FONIX® 7000 Hearing Aid Test System Operator’s Manual Version 1.51 ©2006, Frye Electronics, Inc. All rights reserved Oct.
Contents Chapter 1: Introduction & Setup 1.1 1.2 1.3 1.4 History. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Basic Test Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 Options . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.3.1.2 Noise reduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 2.3.1.3 Delay times. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 2.3.1.4 Harmonic distortion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.5 3.6 3.7 3.8 3.9 3.4.2 Running a Test Curve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69 3.4.3 Example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70 3.4.4 Deleting measurements and settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5.1.7 Testing Digital Hearing Aids. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114 5.1.8 Viewing ANSI measurements in the Coupler screen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114 5.1.9 Explaining the Menu Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115 5.2 ANSI S3.
6.5 6.6 6.7 6.8 6.9 6.4.6 Using Semi-Auto and Fully-Auto Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 151 6.4.7 Testing with a single tone or three frequency average . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 151 6.4.8 Using the reference microphone . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 152 6.4.
Chapter 1 1 Introduction & Setup Welcome to the newest innovation in hearing aid testing! The 7000 Test System is the long-awaited successor to the 6500-CX, the analyzer that arguably has become the standard by which all other hearing aid test equipment is measured. The 7000 Test System has many design improvements, including a high-resolution color display, a flexible and easy-to-use interface, and built-in help screens.
2 FONIX 7000 Hearing Aid Analyzer were implemented and tested on other Frye instruments. The FP40 analyzer introduced “function buttons” that adapt to handle the specific needs of each test screen and sequence. The FP35 analyzer added help screens and local menus to make the analyzer more intuitive and easier to use. The lessons learned in the FP40 and FP35 analyzers have been incorporated into the 7000 Test System.
Introduction and Setup 3 with a probe microphone. Using real-ear measurements makes it possible to individualize the fitting of a hearing aid since a coupler measurement can seldom tell the operator exactly how what sound is received by the client. Many factors affect the sound on its way to the ear drum. When measuring with a probe microphone, you will know what is happening in the “real-ear.” ANSI Option The ANSI Option gives the user access to the ANSI 03, ANSI 96, ANSI 87, and ANSI 92 test sequences.
4 FONIX 7000 Hearing Aid Analyzer 1.4 Accessories The following are accessories that are standard and optional on your FONIX 7000 hearing aid analyzer. 1.4.1 Standard Accessories The following accessories come standard with each 7000 test system. Coupler Microphone—M1950E 14 mm pressure-type electret instrumentation microphone. Note: Older 7000 analyzers may use the M1750E microphone. HA-1 2-cc Coupler Dimensions per ANSI S3.7 for testing in-the-ear aids, canal aids, and aids fitted with earmolds.
5 Introduction and Setup Microphone Adapter 14 mm to 1" (25.4) mm adapter for coupling the M1950E microphone and reference microphone to a 1-inch device such as a sound level calibrator. Test Chamber Cable Connects the main module to the test chamber. Battery Substitution Pills Used to power hearing aids, measure battery drain, and estimate battery life.
6 FONIX 7000 Hearing Aid Analyzer 1.4.2 Real-Ear Accessories When the Real-Ear Option is ordered, the following accessories are included. Remote Module and Microphones The remote module allows the user to control the analyzer while remaining close to the patient. The probe and reference microphones, used for performing real-ear measurements, are plugged into this module. Sound Field Speaker Produces the output for most real-ear measurements.
7 Introduction and Setup Monitor Headset Plugs into the remote module, and allows the user to listen to the signal being measured by the probe microphone. Model of headset may differ from one shown. Wedge-style Ear Hook Standard Size. Holds probe and reference microphone during real-ear testing. Probe Tubes Used for performing real-ear measurements. Probe tubes are not reusable.
8 FONIX 7000 Hearing Aid Analyzer 1.4.3 Optional Accessories Infant/Child Headband Includes infant, child, and adult headbands, six bendable earhooks, and two sets of “animal ears.” 6-cc Coupler Enables checking the response of standard audiometer headphones. It is designed around the NBS 9A coupler specifications. MZ Couplers MZ-3, MZ-2, and MZ-1 couplers are supplied with the OES Option. CIC Coupler Non-standard (0.4 cc) coupler used for realistic testing of CIC hearing aids.
9 Introduction and Setup Open Ear Coupler Non-standard coupler used for realistic testing of open ear hearing aids. #5 battery pill Provides battery current measurements for many CIC hearing aids. Also available: #41 battery pill AA Sound Level Calibrator A portable, self-contained, field-type calibrator for calibrating the microphone amplifier. It operates on one nine-volt transistor battery. Use with 14 mm-to-1" adapter. Calibration is traceable to the U.S.
10 FONIX 7000 Hearing Aid Analyzer Sound Chamber Stand A secure, steel-tube stand that improves sound isolation and brings the testing area of the test chamber to convenient table height. Color matches the electronics module. Sound Chamber Spring Damper Factory-installed.or Assembly Kit. This spring assembly fits onto the back of the sound chamber, making it easier to open the sound chamber lid.
11 Introduction and Setup RECD Earphone Package Consists of one ER3A earphone with a 1⁄4 inch plug, a 72 inch cable, an assortment of ear tips, a calibration certificate, and a lapel clip. This package is suitable for performing an RECD measurement with the 7000 Test System. 1.5 Layout, Controls, and Safety This section describes the basic layout of the front and rear panel of the 7000 test system, and special information pertaining to safety regulations. 1.5.
12 FONIX 7000 Hearing Aid Analyzer • To navigate from screen to screen • To toggle a selection • To pop-up up a selection menu For a more complete description of the operation of the function keys, see Section 2.1.1. [RESET]: Resets the analyzer and returns you to the opening screen. Many settings, measurements, and test conditions are erased or returned to their default conditions with the push of this button. Use [EXIT] instead of [RESET] to avoid the loss of data.
13 Introduction and Setup 1.5.2 Rear Panel Layout The rear panel of the 7000 test system contains most of the external connections for the analyzer. See Figure 1.5.2 for a diagram of the back panel. T630 mAL FONIX 7000 Serial No. 1234 Made in Tigard, Oregon, USA by Frye Electronics, Inc. Frye Electronics products are protected by U.S. and/or foreign patents and/or patents pending Figure 1.5.2—Back panel 1. PRINTER: Connects an external printer to the 7000 test system. 2.
14 FONIX 7000 Hearing Aid Analyzer 11. PROBE: Connects the main module to the remote module (used for real-ear measurements). KEYBD: Not currently active. AUX: Not currently active. The following safety symbols can be found on the back of the 7000 hearing aid analyzer: Type B Equipment. The probe microphone and insert earphone are type B applied parts, according to IEC 60601-1. Read the accompanying documents. Please read this manual before operating the 7000 test system.
Introduction and Setup 15 Connection of peripheral equipment to the 7000 Compliance with IEC 60601-1-1 Safety requirements for medical electrical systems must be determined on a case-by-case basis. All electrical equipment attached to the 7000, such as video monitors, computer equipment, etc. must, at a minimum, meet one of the following conditions: a. The equipment complies with IEC 60601-1 b.
16 FONIX 7000 Hearing Aid Analyzer Otherwise, please report all safety related concerns to the Frye factory: Frye Electronics, Inc. 9826 SW Tigard St. Tigard, OR 97223 Ph: (503) 620-2722 or (800) 547-8209 Fax: (503) 639-0128 email: support @frye.com sales@frye.com Frye Electronics, Inc. is a Registered Firm of British Standards Institution, and we conform to the ISO 13485 standard. 1.6 Setup This section describes the unpacking and setup of the 7000 test system.
Introduction and Setup 17 1.6.2 Locating and arranging the 7000 test system Locate the 7000 test system in a moderately quiet area, such as a private office or laboratory. In order for test results to reliably conform to specifications, the ambient noise, mechanical vibrations, electrical or magnetic fields must not affect test results by more than 0.5 dB (ANSI S3.22). Low-noise acoustic conditions, as found in sound treated rooms and booths, are recommended but not necessary.
18 FONIX 7000 Hearing Aid Analyzer 7020 Sound Chamber M1950E Microphone Speaker Telecoil board (optional) Earphone ATTENTION: Ground reliability can be achieved ONLY when equipment is connected to “HOSPITAL GRADE” receptacles. For service refer to qualified personnel only. Consult accompanying documents. GAIN AUX EARPHONE T630 mAL MICROPHONE SPKR KEYBD Telewand (optional) CALIBRATED Frye Electronics, Inc. 800-547-8209 www.frye.
Introduction and Setup 19 4. Depending on whether you have a floor stand or a swing arm, either (1) Unfold and extend the floor stand to the desired height, about the level of a seated client’s ear, or (2) Mount the wall/desk bracket of the swing arm in a convenient location. Attach the loudspeaker to the stand or arm, using the threaded connection. 5. Plug the dual banana plug into the rear jacks of the loudspeaker. Then plug the other end of the cable into the main module where it is marked “SPKR.” 1.
20 FONIX 7000 Hearing Aid Analyzer The 7000 microphones should be wiped with a dry cloth. Excess moisture may damage the microphones. Solvents and abrasives will cause permanent damage to the 7000. 1.7.2 Care & Maintenance of your M1950E Coupler Microphone Microphones are perhaps the most delicate of FONIX products. They require care and concern when handled. At the risk of sounding negative, the following is a list of the five microphone DON’Ts. 1.
Introduction and Setup 21 Figure 1.7.3A—Serial number location The software version of your 7000 test system can be found on the Opening screen. See Figure 1.7.3B. Press [HELP] to open a help window with more detailed service information. This data may be requested if you call in with a repair-related question. Press [HELP] again to close the help window. Figure 1.7.
22 FONIX 7000 Hearing Aid Analyzer 1.7.4 Contacting the Factory If you have any questions regarding your instrument, have your serial number and software version ready (see Section 1.5.3), and contact us at: Mailing address: Shipping address: Frye Electronics, Inc. PO Box 23391 Tigard OR 97281-3391 USA Frye Electronics 9826 SW Tigard St. Tigard, OR 97223 USA Phone: (800) 547-8209 or (503) 620-2722 Fax: (503) 639-0128 Email: sales@frye.com (sales questions) Support@frye.
Chapter 2 23 General Operation This chapter describes the general operation of the 7000 test system, including basic operation of the buttons, screen navigation, default settings, source types, printing, and other information. 2.1 Operation of buttons The general operation of the various buttons on the 7000 test system are described in this section. This includes a description of the function buttons, the arrow buttons, and the Menu, Help, Reset, Exit, Level, Feed, Print, Stop, and Start buttons. 2.1.
24 FONIX 7000 Hearing Aid Analyzer There are three basic uses of the function keys: • To navigate from screen to screen • To toggle a selection • To pop-up a selection menu Navigation In the Opening screen, the function keys are used to navigate between the various measurement screens. For example, pushing [F1] in the Opening screen will take you to the Coupler screen.
25 General Operation 2.1.2 Navigating through the screens The function keys are used to move from screen to screen. Here is a flow chart of all the available screens and the buttons used to open each screen. Some of the screens will only be available to you if you’ve ordered a certain option. OPENING SCREEN F1 F2 Coupler Screen F1 Audiogram Entry F3 Real-Ear Menu F4 F2 F3 Target Edit Insertion Gain F4 Figure 2.1.2—Navigation Flow Chart F5 SPL F6 Other Tests ANSI S3.42 ANSI S3.
26 FONIX 7000 Hearing Aid Analyzer 2.1.3 Using the pop-up help windows Each operational screen on the 7000 test system has a local help window designed to give you a basic operational overview of the current screen. In general, these help windows tell you what each button does in the current screen. See Figure 2.1.3 for an example. To clear the help window, press [HELP] again or the [EXIT] button. Figure 2.1.
General Operation 27 2.1.4 Using the local menus Pressing the [MENU] button will pop up a local menu that, like the help window, will be overlaid on your current screen. Each local menu contains selections specific to your current screen. For instance, when you are in the Coupler screen, the local menu will contain only selections specific to coupler measurements. See Figure 2.1.4 for an example of a local menu. Figure 2.1.4—Local menu Some local menu selections are common across screens.
28 FONIX 7000 Hearing Aid Analyzer 2.1.5 Using the EXIT and RESET buttons The [EXIT] and [RESET] buttons can be used to exit from any screen, menu, or window. The [RESET] button resets the analyzer and returns it to the start screen. By default, this start screen is the Opening screen with the Frye logo. However, the user can change the start screen to be the Coupler Multicurve screen by changing the settings in the Default Settings (see Section 2.2.1).
General Operation 29 2.2.1 Saving and loading default settings All of the settings in the Setup menu (described in Section 2.2.4) can be saved as default settings. There are five possible setups, so you can have five different configurations saved into the analyzer’s permanent memory. To save a user configuration: 1. Open the Setup menu by pressing [MENU] from the Opening screen. 2. Set up the Setup menu as desired. All displayed settings will be saved, so make sure that you check all fields.
30 FONIX 7000 Hearing Aid Analyzer 2.2.3 Setting the user mode There are two different user modes available on the 7000 test system: Beginner and Expert. In the Beginner mode, extra help windows pop up automatically when function keys are pressed in order to give the user more direction in using the instrument. In Expert mode, those help windows are eliminated. To change the user mode: 1. Press [MENU] in the Opening screen to open the Setup menu. 2. Use [∨, ∧] to select User under Other. 3.
General Operation 31 START SCREEN: The screen shown when the analyzer is powered on or the [RESET] button is pressed. COUPLER sets this screen to the Coupler Multicurve screen. OPENING sets this screen to the Opening screen with the Frye logo. Date/Time YEAR/MONTH/DAY/HOUR/MINUTE: Current date and time. See Section 2.2.2. AM/PM/24: Clock setting. Choose between using AM and PM settings or the 24hour clock.
32 FONIX 7000 Hearing Aid Analyzer NOISE RED (TONE): Pure-tone noise reduction for real-ear measurements. See Section 2.3.1.2. NOISE RED (COMP): Composite noise reduction for real-ear measurements. See Section 2.3.2.1. SMOOTHING: Status of smoothing, which rounds off real-ear curves and removes minor peaks. Turn it ON or OFF. RECD MODE: Real-ear to coupler difference used in real-ear conversions such as HL to SPL.
33 General Operation harmonic distortion measurement should be ignored. Choose ON to apply this rule. Choose OFF to ignore this rule. ANSI OPTION: Modifications to the ANSI test sequences. VA-CORFIG adds the modification requested by the Veterans Administration of the United States. CIC adds CIC correction factors and is meant to be used with the CIC coupler. BATTERY MEAS: Status of the battery current measurement. Turn it ON or OFF. EQUIV NOISE TEST: Status of the equivalent input noise measurement.
34 FONIX 7000 Hearing Aid Analyzer 2.3.1.1 Pure-tone settings There are several different settings available for pure-tone sweeps. You can change all of them in the Setup menu (see Section 2.2). Some of these settings are also available in local menus. Here is an explanation of the pure-tone settings. NOISE RED (TONE): The amount of noise reduction used in pure-tone measurements. This is set independently for real-ear and coupler measurements. See Section 2.3.1.2.
35 General Operation HFA (High Frequency Average) SPA (Special Purpose Average) SPA SPA SPA IEC–(HAIC) 1000, 1600, 2500 800, 1250, 2000 1250, 2000, 3150 1600, 2500, 4000 2000, 3150, 5000 500, 1000, 2000 2.3.1.2 Noise reduction Noise reduction is used in noisy testing environments. Pure-tone noise reduction takes several measurements at each frequency and averages those measurements together.
36 FONIX 7000 Hearing Aid Analyzer In addition to the delays, the aid type will also have an effect on the way some measurements are made. With a selection of ADAPTIVE, the analyzer will throw away the first three measurements of all averaging (including reference test gain) and harmonic distortion measurements. This will increase the amount of time it takes for the test, but it should increase the accuracy of the test for adaptive AGC aids.
37 General Operation tone sweeps with speech-weighted Composite or Digital Speech signals. For this reason, we have made it possible to “weight” the real-ear pure-tone sweeps on the 7000 hearing aid test system. The TONE FILTER selection is available in the Setup Menu under Real-ear settings and in the local menus of the Real-Ear Insertion Gain and Real-Ear SPL measurements screens.
38 FONIX 7000 Hearing Aid Analyzer A significant advantage of using a composite signal is that each frequency present in the signal can be individually controlled in amplitude and phase. As the analyzer goes through the leveling process, each component is adjusted to produce a signal that is optimally accurate at the reference point where the leveling microphone is located. The 7000 test system is able to equalize the amplitudes to within 0.25 dB for coupler measurements made with the Composite signal.
General Operation 39 Figure 2.3.2.2—Example of IM distortion 2.3.2.3 Composite filter There are two main types of composite filters (also known as “speech weighting”): ICRA and ANSI. They differ in the speech spectrum they use. The ANSI filter, taken from the ANSI S3.42 standard, rolls off the high frequencies at a rate of 6 dB per octave, starting with a 3 dB drop at 900 Hz. The ICRA filter uses the ICRA speech spectrum developed by the International Collegium of Rehabilitative Audiology.
40 FONIX 7000 Hearing Aid Analyzer Figure 2.3.2.3—Comparison of the ICRA shape and the ANSI shape 2.3.2.4 Composite type There are two types of the traditional Composite signal available on the 7000 test system. They are known as “Standard” and “Chirp.” The two signals differ in the manner that their phase is generated, and this difference has an impact on the crest factor of the signals. The crest factor of a waveform is the ratio of its highest amplitude to its RMS amplitude.
General Operation 41 Chirp Composite signal is the standard composite signal used on the FP40 and FP35 portable hearing aid test systems. Although the Standard and Chirp Composite signals sound the same to most people, an analysis tool such as Tempus3D will show the difference between them. Both the Standard and the Chirp Composite signals are further speechweighted to agree with the user-selected composite filter (described in Section 2.3.2.3.) 2.3.2.
42 FONIX 7000 Hearing Aid Analyzer 2.3.2.6 Digital Speech technical details The digital speech signal works by turning the composite signal on for a set period of time, taking a measurement, turning the signal off for a random period of time, and turning the signal back on again. This sequence is repeated until the test ends. The signal “on” time takes a minimum of 60 milliseconds. This includes the time to turn the signal on, take the measurement, and turn the signal off.
General Operation 43 To set the default printer, and/or to set the external printer language and color choice, use the Setup menu: 1. Press [MENU] from the Opening screen to open the Setup menu. 2. Use [∨, ∧] to select Printer under General. 3. Use [>] to make your printer selection (INTERNAL or EXTERNAL). 4. Use the arrow keys to make the desired selections for EXT PRNT COLOR and EXT PRNT LANGUAGE, if you are using an external printer. 5. Press [MENU] to close the menu. 6.
44 FONIX 7000 Hearing Aid Analyzer If you want to include a label on all printouts by default: 1. Press [MENU] from the Opening screen to enter the Setup menu. 2. Use [∨, ∧] to select Print Label. 3. Use [>] to select ON. 4. Press [MENU] to close the Setup menu. 5. Press [F8] to save the user defaults. This will also save all the other selections in the Setup menu. 6. Press [EXIT] to return to the Opening screen. 2.4.
45 General Operation • Init failed 0: No memory available for the converted screen buffer • Init failed 1: No memory available for the label bitmap • Init failed 2: Printer driver unresponsive • Init failed 3: Version number from printer board is unreadable Errors that occur when actually printing have the following error codes: • Print failed 0: Switching from internal to external printer failed • Print failed 1: Copying the label bitmap to the printer board has failed • Print failed 2: Converting of
46 FONIX 7000 Hearing Aid Analyzer Figure 2.4.4A—The internal printer Step II: Loading paper into the printer 1. Turn on the instrument. 2. Place the Head-Up lever into the up position. See Fig. 2.4.4B. 3. Unroll approximately six inches of paper from the roll, and insert the paper’s leading edge into the bottom of the printer, directly behind the rubber roller. See Fig. 2.4.4C. Figure 2.4.4B—Head-Up lever in up position.
47 General Operation Figure 2.4.4C—Loading paper into the printer 4. While holding the paper in place behind the rubber roller, manually turn the thumbwheel to advance the paper approximately one inch. Never press the [FEED] button while the Head-Up lever is in the up position. See Note 2 at the end of this section. 5. Center the paper on the rubber roller. Visually inspect the paper path to ensure that the paper advances smoothly without hitting the edges of the printer.
48 FONIX 7000 Hearing Aid Analyzer 8. Tear off excess paper by pulling the paper against the thermal head at approximately a 45º angle. 9. Close the printer door. Press the [FEED] button to advance the paper through the printer door slot. You can tear off excess paper by pulling it upward against the tear strip (on top of the pritner door opening) at approximately a 45º angle. You are now ready to print. Note 1: Whenever the printer door is opened, you will need to repeat steps 8 and 9.
49 General Operation 2.4.7 Putting multiple screens on a page When printing with an external printer, it is possible to save paper by putting two screen prints on one piece of paper. This is done by printing the first screen on one half of the paper and leaving the paper halfway through the external printer until you choose to print the second screen. To do this: 1. Press [MENU] in the Opening screen to open the Setup menu. 2. Change Ext Prnt #Scrns/Page under General to 2.
50 FONIX 7000 Hearing Aid Analyzer Curve Name: This identifies the name of each curve. The first letter is derived from its measurement type—coupler (C) or probe (P). The second letter is derived from its ear—left (L) or right (R). (Coupler curves can also be labeled A and B.) The third letter is the number of the curve. CR1 is the first coupler curve for the right ear. PL2 is the second probe curve for the left ear. Curve Title: This identifies the title of the real-ear curve.
51 General Operation RMS Out: The root-mean-square of the measured curve. Correction Factors (COR): The coupler correction factors used to make the measurement. Coupler screen only. Noise Reduction: The noise reduction used to make the measurement. See Sections 2.3.1.2 and 2.3.2.1. Lastly, just to the right of the Curve Name column, the 7000 test system uses symbols to describe the display status of the curves.
52 FONIX 7000 Hearing Aid Analyzer Figure 2.5.2—Data display of a composite measurement 2.6 Computer Connection The 7000 test system is equipped with an RS232 connection that will allow you to connect to a personal computer and exchange data. You will also need a software program, such as WinCHAP, on your Windows computer that can communicate with the analyzer. It is possible to make your own program using the FRYERS protocol. 2.
53 General Operation Figure 2.7—Remote Module 2.8 Leveling Leveling is the process by which the response of the sound chamber or sound field is measured and computer-corrected so that a flat sound field is achieved. Sound chamber leveling can be saved into permanent memory, but sound field leveling for real-ear measurements must be done for every patient and every ear. See Section 3.2.1 and Section 6.2.4 for instructions on how to perform coupler and real-ear leveling, respectively.
54 FONIX 7000 Hearing Aid Analyzer • WEAK_LEVELED: Tolerances are the same as SEMI-LEVELED but the maximum output for the speaker is less than 100 dB for coupler measurements or 80 dB for real-ear measurements. To achieve a louder signal, the speaker needs to be moved closer to the analyzer microphone and re-leveled. If a leveling error occurs during sound chamber leveling, check the connections of the sound chamber and the microphone, and make sure that you are getting noise out of your sound chamber.
Chapter 3 55 Basic Sound Chamber Tests In the Coupler screen, you can view measurement curves in dB SPL or dB Gain, and run them with Composite, Digital Speech, or pure-tone signals. You can display up to 10 curves on the Coupler screen at the same time. From the Opening screen of the 7000 test system, enter the Coupler screen by pressing [F1]. The Coupler Multicurve screen can be set as the screen that appears when the 7000 test system is powered or the [RESET] button is pressed. See Section 2.2.1 and 2.
56 FONIX 7000 Hearing Aid Analyzer Refer to Figure 3.1.1 for the following explanation of the graphical display: 1. Type of display. This will be either dB SPL (coupler output) or dB Gain (coupler gain). 2. Selected ear. 3. Curve Characteristics box. See Section 2.5.1 for more details. 4. Signal type and leveling status. 5. Selected noise reduction. 6. Maximum output and three-frequency average of the selected curve. 7. Source Signal Statistics Box.
Basic Sound Chamber Tests 57 4. Signal type, speech weighting, leveling status, and bias status (Digital Speech only). 5. Selected noise reduction. 6. Source Signal Statistics Box. Displays the source amplitude. 3.2 The Leveling Process Leveling is the process by which the response of the sound chamber is measured and computer-corrected so that a “flat” sound field is achieved.
58 FONIX 7000 Hearing Aid Analyzer Figure 3.2.1—Leveling the sound chamber Note: See Section 5.1.1 for the ANSI standardized leveling procedures. 3.2.2 Removing the leveling of the sound chamber: In some instances, you may want to look at the response of the sound chamber without the benefit of leveling. In order to do this, you will need to remove the leveling of the sound chamber. To do this: 1. Disconnect the microphone or the sound chamber. 2. Push the [LEVEL] button. The leveling will be removed.
59 Basic Sound Chamber Tests 3.3.1 Explaining the Coupler Types The HA-1 direct access coupler is used to test in-the-ear and canal aids, and aids with molds connected. Figure 3.3.1B shows the direct access coupler. The sound bore of the aid is sealed directly to the 2-cc cavity of this coupler with Fun-Tak putty, provided with the instrument. The HA-2 coupler approximates the human ear with an earmold attached. See Figure 3.3.1A. Note the tube that simulates the earmold.
60 FONIX 7000 Hearing Aid Analyzer to duplicate that used by the manufacturer to obtain the original data. For ANSI tests, use #13 thick-walled tubing with a length of 0.4 inches (10 mm). When cutting tubing to length, leave extra space at each end to go around the nubs of the ear-level adapter and the hearing aid hook. Both the HA-1 and the HA-2 couplers have an O-ring located deep within them that reduces pressure on the inserted microphone, thereby reducing damage to the microphone.
Basic Sound Chamber Tests 61 4. Seal any vent on the aid with a small kernel of Fun-Tak. 5. Complete the acoustical sealing of the aid to the coupler by using a pencil or finger. You may want to double-check the aid placement through the open end of the coupler at this point. Slowly reinsert the coupler microphone into its access opening. 6. Place the completed assembly at the reference position in the test chamber. With ITEs, the position of the aid can affect the frequency response.
62 FONIX 7000 Hearing Aid Analyzer 3.3.3 Behind-The-Ear (BTE) Aids 1. Insert the coupler microphone into the HA-2 2-cc coupler. 2. Couple the aid to the HA-2 coupler using the ear-level adapter. There should be 0.4 inches (10 mm) of tubing between the nub of the ear-level adapter and the nub of the coupler adapter. See Figure 3.3.1-C. 3. Place the microphone of the hearing aid at the reference point in the chamber, as shown in Figure 3.3.3. 4. Close the lid and test as desired. Figure 3.3.
63 Basic Sound Chamber Tests We have also developed a non-standard coupler for open-ear hearing aids. It has two design purposes: 1) To make an convenient connection between the hearing aid and the coupler, and 2) To provide a more real-ear like frequency response than is possible with an HA-1 or HA-2 coupler. Figure 3.3.4C shows a picture of the open-ear coupler with an attached hearing aid. Figure 3.3.4A—HA-2 Coupler Figure 3.3.4B—HA-1 Coupler Figure 3.3.4C—Open-ear coupler Figure 3.3.
64 FONIX 7000 Hearing Aid Analyzer Figure 3.3.4D—Comparison of couplers with open-ear hearing aid. Curve 1 was measured using the Open Ear coupler, Curve 2 with an HA-1 coupler, Curve 3 with an HA-2 coupler, and Curve 4 is the KEMAR real-ear response. 3.3.5 Body Aids 1. Insert the coupler microphone into the HA-2 coupler. (The most consistent results for body aids can be obtained by locating the 2-cc coupler outside the test chamber, preferably on a foam pad to isolate it from vibration.) 2.
65 Basic Sound Chamber Tests Figure 3.3.5A—Coupler setup Figure 3.3.5B—Body Aid in test chamber 3.3.6 Eyeglass Aids 1. Follow the manufacturer’s instructions for removing the hearing aid assembly or the temple piece from the eyeglass frame, if possible. Should you be unable to remove the aid assembly or temple from the frame, it is possible to place the entire frame in the test chamber for testing. Be sure to fold the glasses first. 2. Insert the coupler microphone into the HA-2 coupler. 3.
66 FONIX 7000 Hearing Aid Analyzer Figure 3.3.6—Eyeglass Aid Set-up 3.3.7 Wireless CROS and BICROS Aids The key to testing these aids is to get the proper amount of separation between the transmitter and the receiver. This separation may be vertical. The transmitter may be in the chamber while the receiver is on top of it. If you are using a CRT monitor, it may be necessary to turn it off while testing these aids, because CRT monitors create magnetic fields which may interfere with testing.
67 Basic Sound Chamber Tests Receiver/Coupler Assembly located parallel to Transmitter, at specified distance (d ) (see manuf. specs). Transmitter located at Reference Point Place foam under assembly if necessary to achieve specified distance “d.” d Figure 3.3.7—Testing Wireless CROS Hearing Aids 4. Place the receiver on top of the lid of the test chamber. The total depth of the lid of the test chamber is about 5 ½ inches (14 cm).
68 FONIX 7000 Hearing Aid Analyzer Additional Notes for Testing Wireless Instruments 1. There must not be any metal objects between the transmitter and the receiver sides. 2. The two sides must be directly parallel as illustrated (See Figure 3.3.7). 3. The distance between the two sides should be as specified by the manufacturer. THE GAIN OF THE AID INCREASES AS THE TRANSMITTER AND RECEIVER MOVE CLOSER TO EACH OTHER. EVENTUALLY, THE RECEIVER WILL OVERLOAD. 4.
Basic Sound Chamber Tests 69 3.4.1 Signal Types The following signal types are available: DIGITAL SPEECH—A randomly interrupted composite signal designed to mimic speech. This signal is for use with hearing aids with a “noise reduction” or “speech enhancing” feature that lowers the gain of the aid in the presence of a continuous signal (such as the regular composite signal). COMPOSITE—A continuous real-time, speech-weighted signal made up of 79 different frequencies.
70 FONIX 7000 Hearing Aid Analyzer Figure 3.4.2—Pure-tone measurement 3.4.3 Example Following the instructions above, run 4 Gain curves using amplitudes 50, 60, 70, and 80 dB SPL. Use a signal source of COMPOSITE. This scenario will provide you with a family of curves. Whenever the curves sit on top of each other, the gain of the aid is the same for the amplitudes of those curves. This indicates the aid is running linearly.
Basic Sound Chamber Tests 71 6. Use [F2] to select CRV 2. 7. Use [∧] to select a source level of 60 dB SPL. 8. Press [START] to run the second measurement. Press [STOP] when the measurement has stabilized. 9. Use [F2] to select CRV 3. 10. Use [∧] to select a source level of 70 dB SPL. 11. Press [START] to run the third measurement. Press [STOP] when the measurement has stabilized. 12. Use [F2] to select CRV 4. 13. Use [∧] to select a source level of 80 dB SPL. 14.
72 FONIX 7000 Hearing Aid Analyzer Figure 3.4.3B—Family of curves. Notice how the curves show less gain as the amplitude increases. This aid shows a great deal of compression between 50 dB and 80 dB. 3.4.4 Deleting measurements and settings Use the [F4] key to permanently delete measurement curves. When you press it, there are four possible selections: • Selected Curve: Delete only the selected curve, but keep the curve selections (usually source type and level).
Basic Sound Chamber Tests 73 3.4.5 Running a Single Frequency Measurement At times, you may want to find out what the frequency response of the hearing aid is to a single pure-tone signal. See Figure 3.4.5. 1. Press [MENU] from the Coupler screen. 2. Use [∨, ∧] to select Static Tone under Source Settings. 3. Use [<, >] to choose SINGLE. 4. Press [EXIT] to return to the Coupler screen. The single tone will automatically be running. 5. Adjust the frequency using the [<, >] buttons.
74 FONIX 7000 Hearing Aid Analyzer 3. Use [<, >] to choose AVERAGE. 4. Use [∨, ∧] to select Avg Freqs under Aid Settings. 5. Use [<, >] to choose the highest frequency of the three frequency average. See Section 2.3.1.1 for a complete list of frequencies. 6. Press [EXIT] to return to the Coupler screen. The three frequency average will automatically be running. 7. Adjust the amplitude using the [∧,∨] buttons. Figure 3.4.6—Measuring a three frequency average 3.4.
Basic Sound Chamber Tests 75 3RD: Distortion present at the third harmonics, or three times the presented frequency. TOTAL: Distortion present at the second and third harmonics. 4. Press [EXIT]. 5. Use [F5] to select a signal type of TONE NORMAL. (Press [F5]. Use [∨, ∧] to select TONE NORMAL. Use [>] to complete the selection and close the pop-up menu.) 6. Press [START] to run normal frequency sweep.
76 FONIX 7000 Hearing Aid Analyzer 3.4.8 Intermodulation Distortion The composite signal is helpful for identifying intermodulation distortion (IM), a type of distortion that sometimes occurs in a hearing aid response. IM distortion occurs when more than one frequency is present in the source signal and those frequencies combine to create new frequencies not actually present in the source. IM distortion is disturbing to the client, often more so than harmonic distortion.
Basic Sound Chamber Tests 77 3.4.9 Battery Current Drain You can measure the battery current drain in the Coupler screen if you use battery pills (instead of regular batteries) in the hearing aid while performing your measurements. To turn on the battery current drain measurement in the Coupler screen: 1. Set up the hearing aid in the sound chamber for testing. You must use a FONIX battery pill to test for current drain. 2. Press the appropriate battery button inside the sound chamber. 3.
78 FONIX 7000 Hearing Aid Analyzer 3.4.10 Telecoil Telecoil measurements can be performed in the Coupler screen using any of the source signals available on the 7000 Hearing Aid Test System. During a telecoil measurement, a magnetic field is used that is supposed to simulate the field of a telephone receiver. A telecoil board capable of producing this field is built into every 7000 sound chamber. When the analyzer has the ANSI option, the external Telewand can also be used for the measurement.
Basic Sound Chamber Tests 79 8. Use [∧, ∨] to change the intensity of the magnetic field. The choices are: OFF, 1.00, 1.78, 3.16, 5.62, 10.0, 17.8, 31.6, 56.2, and 100 mA/m. 31.6 is the default source intensity. 9. Press [STOP] to stop the measurement or continue to test, as desired. Figure 3.4.10A—Testing with the Sound Chamber Telecoil Board Testing with the Telewand When the ANSI Option is ordered with the 7000 Hearing Aid Test System, the Telewand device is also included.
80 FONIX 7000 Hearing Aid Analyzer is in a vertical position. If necessary, use Fun Tak to help hold the aid in that position. See Figure 3.4.10B. 5. Use [∧, ∨] to change the intensity of the magnetic field. The choices are: OFF, 1.00, 1.78, 3.16, 5.62, 10.0, 17.8, 31.6, 56.2, and 100 mA/m. 31.6 is the default source intensity. 6. Press [STOP] to stop the measurement or continue to test, as desired. Figure 3.4.10B—Testing with the Telewand 3.4.
Basic Sound Chamber Tests 81 Speaker Placement The speaker in the 7000 sound chamber is positioned on the right side of the chamber at a 45º angle, as illustrated in Figure 3.4.11A. It is important to keep this in mind when positioning the directional hearing aid for measurements. Figure 3.4.
82 FONIX 7000 Hearing Aid Analyzer Figure 3.4.11B—Forward directional measurement. Reverse measurement Next, open the sound chamber and position the hearing aid so that the front of the hearing aid is pointing towards the left side of the chamber. See Figure 3.4.11C. Different hearing aids have different null points so you will want to adjust the positioning so that the sound chamber speaker is pointing towards what should be the null point of the directional aid.
Basic Sound Chamber Tests Figure 3.4.11C—Reverse directional measurement Figure 3.4.
84 FONIX 7000 Hearing Aid Analyzer 3.5 Digital hearing aids All digital aids can be tested, but some of the high-end models require a little more thought and care; these aids have a “noise suppression” feature (also known as “speech enhancement”). This noise suppression, not to be confused with the automatic compression of AGC hearing aids, checks if the sound going into the hearing aid is a continuous signal that could be regarded as noise.
Basic Sound Chamber Tests 85 5. Use [F5] to choose the DIG SPEECH signal source. It will now have the ICRA speech weighting. See Figure 3.5.2 for a comparison of an aid tested with the ANSI and ICRA speech weightings. 5. Use [F5] to choose the DIG SPEECH signal source. It will now have the ICRA speech weighting. See Figure 3.5.2 for a comparison of an aid tested with the ANSI and ICRA speech weightings. Figure 3.5.
86 FONIX 7000 Hearing Aid Analyzer Figure 3.5.3—Using the bias signal with Digital Speech. CRV 1-3 have bias signals at 500 Hz, 1000 Hz, and 4000 Hz respectively. CRV 4 was performed with Digital Speech and no bias signal. 7. Use [<, >] to change the frequency of the bias signal. The current selected frequency will be displayed on the screen below the Curve Characteristics Box. 8. Press [STOP] when done with the measurement. See Figure 3.5.
Basic Sound Chamber Tests 87 2. Use [F2] to select CRV 1. (Press [F2]. Use [∨, ∧] to select CRV 1. Use [>] to complete the selection and close the pop-up menu.) 3. Use [F5] to select DIG SPEECH in the same manner as described above. 4. Use [∨, ∧] to select a normal speech amplitude, such as 65 dB SPL. 5. Make sure the digital noise suppression feature is enabled on the hearing aid, and set it up for testing in the sound chamber. 6. Press [START] to begin the measurement.
88 FONIX 7000 Hearing Aid Analyzer 3.5.5 Understanding Terminology With the new testing terminology of hearing aid analyzers combined with the new technology of hearing aids, it’s easy to get terminology confused. “Noise Reduction” is a term that Frye Electronics has always used to denote the averaging that the analyzer makes when analyzing data to achieve a smooth curve. This process is described in Section 2.3.1.2 and Section 2.3.2.1.
Basic Sound Chamber Tests 89 8. Press [START] to perform the measurement. You should see CIC appear in the Curve Characteristics box in the “Cor” column of the selected curve. If you are using the FAST, COMPOSITE, or DIG SPEECH signal, press [STOP] to end the measurement once it has stabilized. Figure 3.6 shows the difference between a CIC hearing aid tested with an HA-1 coupler, and the same aid tested with a CIC coupler and correction factors. Figure 3.
90 FONIX 7000 Hearing Aid Analyzer To use the OES Option: 1. Attach the MZ coupler to the aid. See Table 3.7 for details on choosing the correct MZ coupler. 2. Set up the hearing aid for testing as described in Section 3.3. 3. Press [MENU] in the Coupler screen. 4. Highlight Coupler Type under Measurement Settings with [∨, ∧]. 5. Select MZ with [<, >]. 6. Press [EXIT]. 7. Select the desired source type with [F5]. (Press [F5]. Use [∨, ∧] to select the desired source type.
Basic Sound Chamber Tests 91 Figure 3.7—Comparison of the responses with the MZ and HA-2 couplers. Curve 2 was measured with an MZ coupler and OES correction factors. Curve 1 was measured using a standard 2-cc coupler. 3.8 Automatic Testing—Loading & Saving Groups You can use the 7000 Test System to program simple automated or semi-automated test sequences that will help you test hearing aids more efficiently.
92 FONIX 7000 Hearing Aid Analyzer If there is a sequence of tests that you would like to perform frequently, you can save it into the 7000 Test System’s permanent memory using the SAVE GROUP function. Three groups of up to 10 curves can be saved into SAVE GROUP 1, 2, and 3, respectively. When you want to load a group that has previously been saved, you use the LOAD GROUP function. See Section 3.8.2. 3.8.
Basic Sound Chamber Tests 93 3.8.2 Loading a Saved Test Sequence It is not necessary to permanently save a custom test sequence, but doing so allows you to bring it up in the Coupler screen at any time, even if you’ve turned off and on the analyzer. Follow the directions in Section 3.8.1 to program and save your custom test sequence. Then, use [F6] to LOAD GROUP 1, 2, or 3. Choose the group you saved in Step 11 of Section 3.8.1. (Press [F6]. Use [∨, ∧] to select the correct LOAD GROUP number.
94 FONIX 7000 Hearing Aid Analyzer 1. If desired, follow the instructions in Section 3.8.2 to load a test sequence. You can do this by following the directions in Section 3.8.1 to create a new sequence, or by loading a previously saved sequence by following the directions in Section 3.8.2. 2. Use [F6] to select SEMI-AUTOMATIC. (Press [F6]. Use [∨, ∧] to select SEMIAUTOMATIC. Press [>] to complete the selection and close the pop-up menu.) 3. Use [START] to start the automated test sequence.
Basic Sound Chamber Tests 95 Measurement Settings • Coupler Type: The type of coupler being used in making sound chamber measurements. Selections of CIC and MZ turn on corresponding software correction factors (see Sections 3.6 and 3.7). A selection of 2CC does not apply correction factors to the curve but will note a 2-cc coupler was used in the COR column of the Curve Characteristics Box. The NONE selection will apply no corrections and leave the COR column blank.
96 FONIX 7000 Hearing Aid Analyzer • Misc Meas Delay: The amount of time each subsequent tone is presented before the measurements is made in one of the measurements listed above. See Section 2.3.1.3. Misc Settings • Battery Meas: Status of the battery current measurement. Choose ON or OFF. • Battery Size: Size of battery used with the hearing aid being tested. • Print Label: Status of the printing label. Choose ON or OFF. • Printer: Printer used for printouts. Choose INTERNAL or EXTERNAL. See Section 2.4.
Chapter 4 97 Advanced Coupler Tests 4.1 Enhanced DSP The Enhanced DSP measurement screen was designed to give you more information about digital hearing aids. The new technology in digital hearing aids has added a great deal of capability such as increased clarity and flexible programming. However, the same technology can also have its pitfalls. This test will tell you the digital processing delay (also known as group delay) and the signal phase of the hearing aid.
98 FONIX 7000 Hearing Aid Analyzer Technical details The digital processing delay measurement is taken by sending a short impulse from the sound chamber speaker to the hearing aid. The 7000 Test System microphone collects information from the hearing aid for 20 milliseconds from the time the impulse is delivered. This information is a series of numbers of varying amplitudes. The 7000 Test System finds the maximum peak amplitude of the resulting information.
Automated Test Sequences 99 It then continues through a complete cycle and terminates when it reaches the baseline again. This signal, although consisting of only a single pulse, contains very few frequencies above 1 kHz and is one millisecond wide at its base. The data collected from this measurement is displayed in a graphical format 20 milliseconds wide. The system delay and the digital processing delay are noted for reference on the phase graph in the form of vertical lines. 4.1.3 Procedure 1.
100 FONIX 7000 Hearing Aid Analyzer When measuring a set of binaural hearing aids, both the phase and the delay graphs should match fairly closely. 4.2 Battery Current Test The Battery screen lets you perform extensive tests on the amount of battery current that the hearing aid uses. These tests were designed to give you a complete picture of the amount of battery current that the hearing aid drains when exposed to different situations.
Automated Test Sequences 101 Figure 4.2—Battery Current Test 1. mA/Freq graph 2. mA/Ampl graph 3. Static test (estimated battery life) 4. Selected test settings. 4.2.1 Static Test (Estimated Battery Life) The Static test estimates the battery life of the hearing aid. To turn on the test: 1. Enter the Battery screen (as described above). 2. Use [F7] to set the battery size: Press [F7]. Use [∨, ∧] to select the battery size of the hearing aid. Use [>] to complete the selection and close the popup menu. 3.
102 FONIX 7000 Hearing Aid Analyzer 4.2.2 mA/Freq The mA/Freq test shows how much battery current the hearing aid drains when exposed to different frequencies. By default, it runs a 60 dB SPL LONG puretone sweep. The selected amplitude is displayed below the mA/Ampl graph. This amplitude can be changed by using [∨, ∧]. Press [START] to run the test. A few technical details about this test: • The amplitude used for a test currently being displayed on the screen is shown above the mA/Freq graph.
Automated Test Sequences 103 • You can view the numerical data results by entering the local menu by pressing [MENU] and setting DATA/GRAPH to DATA by using the arrow keys. Close the local menu by using [EXIT] or [MENU] again. Test results will now be shown in tabular data format. • You can turn this test off by toggling the test status with [F6]. If the mA/Ampl graph is not displayed, it will not be measured when [Start] is pressed. • Use [F1] to switch between left and right ear.
104 FONIX 7000 Hearing Aid Analyzer A few technical details about this test: • Choose between showing test results in SPL (Output) and Gain in the local menu. (Use [MENU] to open the local menu, the arrow keys to adjust the selections, and [EXIT] or [MENU] again to close the local menu.) • [F2] sets the aid type. This changes the length of time each stimulus is presented before the measurement is taken. Suitable default delay times are set when the aid type is selected.
Automated Test Sequences 105 Figure 4.4—Attack & Release Test 1. Attack graph 2. Release graph 3. Measured Attack & Release times and test settings. 4. Currrent Attack & Release settings By default, the Attack & Release test uses the settings specified by the ANSI 96 test sequence at 2000 Hz. If you want to perform attack and release measurements using a different standard, use the [F4] key. The available test selections are: IEC Loud, IEC Speech, JIS, IEC, and ANSI 96.
106 FONIX 7000 Hearing Aid Analyzer For most hearing aids, the most interesting part of the attack and release measurements occurs at the beginning of each test. After the aid reaches its settling amplitude, the test result just records a rather uninteresting flat line. The user can zoom in on the beginning of the test by using [F6] and [F7]. These keys rescale the test results to show only the selected time interval. The beginning of the interval is always the beginning of the test.
Chapter 5 107 Automated Test Sequences There are several automated coupler test sequences available for the 7000 hearing aid analyzer. The test sequences present on your analyzer are dependent upon the features purchased when you ordered your unit. If you would like access to a test sequence not present on your unit, you can always order an upgrade. Call the factory or your local distributor for more information. The following test sequences are available: • ANSI S3.22-2003 (ANSI 03) • ANSI S3.
108 FONIX 7000 Hearing Aid Analyzer Here are the main differences between ANSI 87 and ANSI 96: • AGC aids are tested at reduced reference test gain in ANSI 96, but tested at full-on gain in ANSI 87. This will have an effect on nearly all measurement results in the ANSI test sequence. • The input/output and attack & release measurements are performed at up to five different frequencies in ANSI 96. ANSI 87 only measures those functions at 2000 Hz.
Automated Test Sequences 109 3. Position the hearing aid/coupler assembly in the test chamber with the microphone of the aid at the reference point of the chamber. 4. Place the test microphone as close as practical to the hearing aid microphone (3-5 mm). See Figure 5.1.1A. 5. Close the lid of the sound chamber. 6. Press the [LEVEL] button. The sound chamber will level. 7. Exchange the position of the dummy microphone and the test microphone and plug the battery pill into the battery voltage supply.
110 FONIX 7000 Hearing Aid Analyzer 3. For ANSI 87 and ANSI 96, set AGC aids to achieve the greatest possible compression or as otherwise specified by the manufacturer. For ANSI 03, set AGC aids to have the most minimum compression possible or as otherwise specified by the manufacturer. 4. Put the hearing aid in “test mode,” if applicable. All noise suppression and feedback cancellation features should be turned off. 5. Set the gain control of the aid to the full-on position. 6.
Automated Test Sequences 111 2. Push [START] to continue the test. 3A. If you chose to perform a telecoil measurement, do the following steps when the analyzer pauses. If you are running an ANSI 03 test of an AGC aid and are not performing a telecoil measurement, skip to step 3B. Otherwise, just wait for the test sequence to complete. a. Open the lid of the sound chamber. b. Switch the aid to telecoil mode. c.
112 FONIX 7000 Hearing Aid Analyzer 5.1.5 Running an ANSI 87 Test After leveling the sound chamber as described in Section 5.1.1, setting up the aid as described in Section 5.1.2, and setting up the analyzer as described in Section 5.1.3, follow these instructions: 1. Press [START] from the ANSI 87 screen to start the test. 2. If you have enabled the telecoil test, do the following when the sequence stops for the telecoil measurement. Otherwise, skip to step 3. a. Open the lid of the sound chamber. b.
Automated Test Sequences 113 Figure 5.1.6—ANSI 03 test results, Frequency Response Screen 9. RTG Measured: Measured reference test gain 10. EQ Inp Noise: Equivalent input noise measurement 11. Resp Limit: The response limit level is determined by taking the three frequency average of the RESP 50 curve and subtracting 20 dB. F1 is where the RESP 50 curve crosses the response limit level on the way up. F2 is where the RESP 50 curve crosses the response limit level on the way down. 12.
114 FONIX 7000 Hearing Aid Analyzer 18. I/O curve selection box: the key to the I/O graph, listing which frequencies go with which curve. 19. Attack and release measurements, including the frequencies at which they were measured.
Automated Test Sequences 115 1. Run the ANSI test sequence. 2. Press [F6]. 3. Use [∨] to select Store Crvs Coup, if necessary. 4. Press [>] to store the curves and close the menu. The following is a list of where the curves are stored in the Coupler screen. Any previous measurements stored in those curve locations will be overwritten. • SPLITS – CRV 4 • VA CORFIG – CRV 5 • Response – CRV 6 • OSPL90 – CRV 7 5. Press [EXIT] and [F1] to enter the Coupler screen and view the ANSI response curves. 5.1.
116 FONIX 7000 Hearing Aid Analyzer • OSPL90 Sweep Meas Delay—The delay between frequencies in the OSPL90 sweep. • Res Crv Sweep Start Delay—The delay after the first tone is presented in the response curve (at 50 or 60 dB SPL) sweep and before the first measurement is taken. • Res Crv Sweep Meas Delay –The delay between frequencies in the response curve (at 50 or 60 dB SPL) sweep.
Automated Test Sequences 117 5.2 ANSI S3.42-1992 (ANSI 92) The ANSI Option includes a test sequence based on the ANSI S3.42-1992 standard. This standard has been developed to test non-linear hearing aids with a broadband noise signal. The need for this standard stems from the importance of evaluating the performance of these circuits in a more real-world environment. ANSI 92 gives you: noise saturation sound pressure level, noise gain, a family of frequency responses, and a noise input/output curve. 5.2.
118 FONIX 7000 Hearing Aid Analyzer For some aids, the analyzer will pause the test and tell you to turn the aid down to reference test gain. Adjust the volume of the aid until it comes within 1 dB of the target gain. Take care not to move the aid from its position. If you must move it in order to adjust the gain control, replace as close as possible to its original position. Push [START] to complete the test. To delete the displayed results, press [F4] and use [∨, ∧] to select DELETE ALL CRVS.
Automated Test Sequences 119 Figure 5.2.3—ANSI 92 test results 5.2.4 Viewing ANSI measurements in the Coupler screen It’s possible to copy ANSI response curves to the Coupler screen where they can be compared to other response curves. To do this: 1. Run the ANSI 92 test sequence. 2. Press [F6]. 3. Use [∨] to select Store Crvs Coup, if necessary. 4. Press [>] to store the curves and close the menu. The following is a list of where the curves are stored in the Coupler screen.
120 FONIX 7000 Hearing Aid Analyzer 5.2.5 Explaining the Menu Settings There are only a couple of menu settings in the local menu of the ANSI 92 screen. Misc. Settings • Print Label—Status of the printing label. Choose ON or OFF. • Printer—Printer used for printouts. Choose INTERNAL or EXTERNAL. See Section 2.4. 5.3 IEC The International Electro-technical Commission (IEC) standard in the international community is analogous to the ANSI standard in the United States.
Automated Test Sequences 121 5. Level the sound chamber, if necessary (see Section 5.1.1). 6. Plug the battery simulator into the jack near the battery voltage supply. 5.3.2 Running IEC 1. Press [START] from the IEC screen. The instrument will run a measurement and then pause. 2. Turn the gain of the aid down to the reference test position. Match the target value within 1 dB. 3. Press [START] to complete the test sequence. 4. Press [PRINT] to print test results. 5.3.3 Viewing IEC Results 1.
122 FONIX 7000 Hearing Aid Analyzer 7. Reference test gain measured (actual) 8. Reference frequency 9. Total harmonic distortion 10. Equivalent input noise measurement 11. Battery current drain 12. I/O curve measured at the reference frequency 5.3.4 Viewing IEC measurements in the Coupler screen It’s possible to copy IEC response curves to the Coupler screen where they can be compared to other response curves. To do this: 1. Run the IEC test sequence. 2. Press [F6]. 3.
Automated Test Sequences 123 • Misc. Start Delay—The delay after the first tone is presented and before the first measurement is taken in the HFA/SPA, reference test gain, equivalent input noise, and harmonic distortion measurements. • Misc. Meas. Delay—The delay between frequencies in the measurements mentioned above. • I/O Start Delay—The delay after the first tone is presented in the I/O sweep and before the first measurement is taken. • I/O Meas. Delay—The delay between frequencies in the I/O sweep.
124 FONIX 7000 Hearing Aid Analyzer 5.4.2 Viewing JIS Results Figure 5.4.2 See Figure 5.4.2 for the following explanation of test results. 1. OSPL90 response curve 2. Full-on gain response curve measured at 50 or 60 dB SPL 3. Response curve measured at reference test gain at 60 dB SPL 4. Output with a 90 dB input at 500 Hz 5. Output with a 90 dB input at the reference frequency 6. Maximum output and the frequency at which it was measured 7. Gain of the FOG curve at the reference frequency 8.
Automated Test Sequences 125 5.4.3 Viewing JIS measurements in the Coupler screen It is possible to copy JIS response curves to the Coupler screen where they can be compared to other response curves. To do this: 1. Run the JIS test sequence. 2. Press [F7]. 3. Use [∧] to select Store Crvs Coup, if necessary. 4. Use [>] to “store” the curves (that is, copy them to the Coupler screen) and close the pop-up menu. The following is a list of where the curves are copied in the Coupler screen.
126 FONIX 7000 Hearing Aid Analyzer JIS Settings • Equiv Noise Test—Status of the EIN measurement. Turns it ON or OFF. Misc. Settings • Print Label—Status of the printing label. Choose ON or OFF. • Printer—Printer used for printouts. Choose INTERNAL or EXTERNAL. See Section 2.4.
Chapter 6 127 Real-Ear Measurements 6.1 Introduction The Real-Ear Option gives you the capability to make probe microphone measurements inside your client’s ear. You can: • Input audiograms • Create targets • Perform insertion gain measurements • Perform SPL measurements • Perform Visible Speech measurements • Perform RECD measurements 6.1.1 Understanding the Real-Ear Screens There are several different screens associated with real-ear measurements.
128 FONIX 7000 Hearing Aid Analyzer These screens are: • Audiogram Entry screen [F1] • Target screen [F2] • Insertion Gain screen [F3] • SPL screen [F4] • Visible Speech [F5] 6.1.2 Navigating through the Real-Ear Screens The Real-Ear Navigation screen is the key to moving through the different realear screens. • To enter the Real-Ear Navigation screen from the Opening screen, press [F2]. • To enter any of the real-ear screens, press the appropriate function key button from the Real-Ear Navigation screen.
129 Real-Ear Measurements Reference Mic Reference Mic Probe Mic 12" 12" Probe Mic Speaker (45 degrees) Top View Speaker (45 degrees) Front View Figure 6.2.1—Sound field speaker setup 6.2.2 Placing the earhook and reference microphone 1. Place the wedge-style earhook on the client’s ear. 2. Attach the reference microphone, facing forward, on the wedge of the earhook, directly above the ear to be tested. The reference microphone should be as close to the head as possible. See Figure 6.2.2. 3.
130 FONIX 7000 Hearing Aid Analyzer 6.2.3 Inserting the probe tube There are several different methods used for properly inserting the probe tube. Here are two easy methods. Method 1 1. Place an unattached probe tube on a flat surface along with the client’s earmold or shell. 2. Place or hold the ear mold next to the probe tube, so that the tube rests along the bottom of the canal part of the earmold, with the tube extending at least 5 mm past the canal opening.
131 Real-Ear Measurements WARNING Choose OUTPUT LIMITING carefully (see procedure below). You don’t want to damage your clients’ hearing or to cause them discomfort during testing. To ensure safety and comfort, the 7000 Test System reacts automatically when the OUTPUT LIMITING level is exceeded at the Probe Microphone.
132 FONIX 7000 Hearing Aid Analyzer SANITATION NOTICE DO NOT REUSE PROBE TUBES. Use a new probe tube for each ear to prevent the possible spread of infection. Sterilization of probe tubes is not possible, and germicidal solutions can leave a residue inside the tubing which can result in errors. Do not cut off any portion of the tube.
Real-Ear Measurements 133 3. Press [F5] to select the Composite signal as the source type. 4. Press [START] to start a measurement. 5. Insert the probe tube carefully, looking at the composite measurement. At some point, there will be a large dip below the 0 dB level at 6 kHz caused by the standing wave inside the ear. Keep inserting the probe tube until that dip goes away and the unaided response is above 0 dB gain between 6 kHz and 8 kHz. See Figure 6.2.3B. 6.
134 FONIX 7000 Hearing Aid Analyzer Figure 6.2.4—Leveling the sound field speaker 1. Follow the instructions found in Sections 6.2.1 and 6.2.2 to position the client, sound field speaker, and microphones for testing. Only the larger reference microphone is used for leveling. However, to speed things up and ensure the client is in the same position for leveling as he is for measuring, it is recommended that you insert the probe microphone tube in the client’s ear (described in Section 6.2.
135 Real-Ear Measurements If the instrument didn’t successfully level, there are several things you can try. • Check the position of the sound field speaker. It should be 12 to 15 inches from the client’s head. • Make sure the microphones are securely plugged into the remote module. • Make sure the front of the reference microphone is as close to the client’s head as possible. • Check the calibration of the loudspeaker and microphones. See Appendix B. • Check the noise level in the room.
136 FONIX 7000 Hearing Aid Analyzer 4. Make sure HTL is selected above F2. You should see a cursor in the HTL column for the selected ear in the middle of the display. If the cursor is in a different column, press [F2] to select HTL. 5. Use the arrow keys to input the client’s HTL (hearing threshold level) values. Use [<, >] to input the amplitude. Use [∨, ∧] to select the frequency. 6. Use [F5] to select the client’s age. (Press [F5]. Use [∨, ∧] to make the selection.
Real-Ear Measurements 137 6.3.2 Deleting Audiometric Information If you make a mistake, it’s often useful to be able to delete all or part of the inputted audiometric data. To do this: 1. Press [F4] and use [∨, ∧] to select the data you would like to delete. You can delete the client’s HTL, UCL, Bone, and RECD. Selecting “This Ear” will delete all data in the selected ear. Selecting “New Client” will delete all data in both ears. 2. Press [>] to perform the action. 6.3.
138 FONIX 7000 Hearing Aid Analyzer 6.3.4 Entering Bone Data The NAL-NL1 target uses bone data in its calculations. If the patient’s bone thresholds are not entered, it will assume average values. No other fitting rules use the bone data. To enter this data: 1. Press [MENU] in the Audiogram Entry screen to open the local menu. 2. Set the FITTING RULE to NAL-NL1 using the arrow keys. 3. Press [EXIT] to exit the local menu. 4. Press [F2] repeatedly until BONE is selected. 5.
139 Real-Ear Measurements To perform the coupler measurement: 1. Insert the 50 ohm insert earphone into the jack on the back of the 7000 test system labeled “EARPHONE.” 2. Plug the other end of the insert earphone into the tubing of the ear level adapter attached to an HA-2 coupler. See Figure 6.3.5A. 3. Insert a probe tube through the black probe microphone adapter as shown in Figure 6.3.5B. Attach a dab of Fun-tak to the adapter to keep the probe tube from slipping. 4.
140 FONIX 7000 Hearing Aid Analyzer 5. Press [F1] from the Real-Ear Navigation screen to enter the Audiogram Entry screen. 6. Press [MENU] from the Audiogram Entry screen to enter the local menu. 7. Use [∨, ∧] to select RECD Mode under Misc, and use [<, >] to choose Custom Measured. 8. Use [∨, ∧] to select RECD Transducer and use [<, >] to choose ER3. Foam plug or custom earmold ER3 IN EARSERT PHO NE Probe mic Probe mic Figure 6.3.5C—Insert probe microphone Figure 6.3.
Real-Ear Measurements 141 Figure 6.3.5E—Taking an RECD Measurement 6.3.6 Modifying a Target Once you input an audiogram in the Audiogram Entry screen, a target will automatically appear on the real-ear measurement screens. You can use the Real-Ear Target screen to modify a target or to input your own target in dB insertion gain or dB SPL, edit your client’s HTL and UCL values in dB SPL, and input a custom real-ear to dial difference (REDD). 1.
142 FONIX 7000 Hearing Aid Analyzer • REDD: The real-ear to dial difference (only selectable when REDD is set to CUSTOM) • TARG IG: The mid-level target in dB insertion gain 6. Use [F5] to select the signal source if you are modifying the SPL target: • Select the Source Type. Choose between Tone and Composite. Press [START] to make your selection without closing the pop-up window. • Select the Source Level. Choose between 40 through 90 dB SPL. Press [>] to make your selection and close the pop-up window.
Real-Ear Measurements 143 6.3.7 Entering an REDD transform The REDD transform affects how dB HL values are converted to dB SPL. To enter a measured REDD value: 1. Enter the Real-Ear Navigation screen by pressing [F2] from the Opening screen or [EXIT] from a real-ear screen (such as the Audiogram Entry screen). 2. Press [F2] to enter the Real-Ear Target screen. 3. Press [MENU] in the Real-Ear Target screen. 4. Select REDD using [∨, ∧]. 5. Choose CUSTOM using [<, >]. 6.
144 FONIX 7000 Hearing Aid Analyzer In other words, the bottom graph of the insertion gain screen shows the difference between the sound field measured by the reference microphone outside of the ear and the probe microphone in the ear canal. (When the reference microphone is disabled, the estimated sound field is subtracted.) The top graph shows the insertion gain, which are the values obtained when the unaided response is subtracted from the aided response.
Real-Ear Measurements 145 6.4.2 Measuring in the Real-ear SPL screen In the past ten years, the SPL method of performing real-ear measurement has increased in popularity. In the SPL method, the patient’s hearing threshold levels (HTLs), uncomfortable levels (UCLs), real-ear target, and real-ear measurements are displayed together on one graph in terms of dB SPL. This allows for a direct comparison of audiometric measurements and real-ear measurements.
146 FONIX 7000 Hearing Aid Analyzer this section apply to measurements performed in both screens. Any differences between operations in the two screens are noted. To enter the Real-ear SPL screen, press [F2] from the Opening screen to enter the Real-ear Navigation screen. Then press [F4]. Figure 6.4.2—Rear-ear SPL screen. The T curve represnts the patient’s thresholds, the L, M, and H curves represent the NAL-NL1 targets. Curve 1 shows the unaided response.
Real-Ear Measurements 147 5. Enter the Insertion Gain or Real-ear SPL screen by using [F3] or [F4] in the Real-ear Navigation screen, respectively. 6. Level the sound field speaker. See Section 6.2.4. 7. Select the desired ear with [F1]. 8. Look at the [F2] setting to see which curve is selected. If necessary, use [F2] to select REUR 1. (Press [F2]. Use [∨, ∧] to select REUR 1. Press [>] to complete the selection and close the pop-up menu.) 9. Use [F5] to select Composite. 10.
148 FONIX 7000 Hearing Aid Analyzer the local menu. The average unaided response will now be displayed on the measurement graph. To auto-adjust the unaided response: When using the SPL display in the Insertion Gain screen, or when measuring in the Real-ear SPL screen (in other words, when the unaided response is displayed in terms of SPL and not gain), the unaided response includes the input signal used in the measurement.
Real-Ear Measurements 149 pop-up selection menu. Use the up-down arrow keys to make the desired selection. Press the right arrow key to complete the selection and close the menu.) 4. Use [F2] to select REAG 2. By default, this curve is set to 50 dB SPL (i.e., soft speech). To perform a medium speech curve measurement, use the up arrow key to increase the source level to 65 dB SPL. 5. Press [START] to take the measurement. When the frequency response has stabilized, press [STOP] to stop the measurement.
150 FONIX 7000 Hearing Aid Analyzer another measurement curve. It is recommended to perform real-ear measurements as 50, 65, 80, and 90 dB SPL. For this reason, the default source levels of REAG 2-5 are set accordingly. Use the up-down arrow keys to change the selected source amplitude at any time. 6.4.5 Working with prescription targets The 7000 Hearing Aid Test System has the following fitting rules available: NAL-NL1, NAL-RP, 1/3 Gain, 1/2 Gain, 2/3 Gain, Berger, and POGO.
Real-Ear Measurements 151 6.4.6 Using Semi-Auto and Fully-Auto Mode The Real-ear Insertion Gain and Real-ear SPL screens have basic implementations of Semi-Automatic and Fully-Automatic test modes. In Semi-Automatic mode, the analyzer automatically advances to the next measurement curve when the measurement is stopped. That is, if the user selects REUR 1 and takes a measurement, the analyzer will automatically advanced the curve selection to REAR 2.
152 FONIX 7000 Hearing Aid Analyzer 1. Enter the Real-ear Insertion Gain or Real-ear SPL screen. 2. Press [MENU] to enter the local menu. 3. Select Static Tone under Source using [∨, ∧]. Pressing [START] will jump ahead to the beginning of the next section in the local menu. 4. Choose Single or Avg using [<, >]. If choosing Avg for a three-frequency average, use the Avg Freqs setting to select the highest frequency of the three frequency average. See Section 2.3.1.
Real-Ear Measurements 153 To view curve data in the Real-ear Insertion Gain screen: 1. Enter the Real-ear Insertion Gain: 2. Press [MENU] to enter the local menu. 3. Select Data/Graph under Display using [∨, ∧]. 4. Use [<, >] to choose: • AIDED DATA: To view selected aided curve. • IG DATA: To view selected insertion gain curve. • GRAPH: To view in standard graphical (non-numeric) format. 5. Press [EXIT] to return to the Insertion Gain screen.
154 FONIX 7000 Hearing Aid Analyzer 4. Use [<, >] to select DATA. 5. Press [EXIT] to return to the Real-ear SPL screen. The numerical data display will be shown. 6. Use [F2] to select the curve data you want to display. 6.4.10 Deleting and un-displaying measurements It is often convenient to temporarily clear one or more of the measurement curves without deleting them. To turn off/on the display of a curve without deleting it: 1. Press [F3] to open the pop-up menu with the curve selections. 2.
Real-Ear Measurements 155 • From 3000 Hz–8000 Hz, measured data points from seven consecutive frequencies 100 Hz apart are averaged to get the curve point at the center frequency. In normal pure-tone log smoothing: • Each center frequency is smoothed by averaging it together with the outputs from the next upper and lower 12th octave frequency. To turn on/off log smoothing: 1. Enter the measurement screen. 1. Press [MENU] to enter the local menu. 2. Use [∨, ∧] to select Smoothing under Display. 3.
156 FONIX 7000 Hearing Aid Analyzer 6.4.12 Using Output Limiting When performing real-ear measurements, it is very important not to expose your client to noises that could conceivably further damage his hearing. For this reason, the 7000 test system has built-in output limiting. When the probe microphone reads a value above the output limit at any frequency, the test will automatically stop. The default setting for the output limit is 120 dB SPL.
Real-Ear Measurements 157 7. Press [∨] repeatedly until the chosen source is OFF. 8. Press [START] to start the measurement. 9. Instruct your client to sustain the vowel sound “eee.” 10. Press [STOP] while the “eee” is still sounding, and the curve has stabilized. The client can now stop vocalizing. 11. Look at the amplification in the low frequencies. If it seems high, you may consider adjusting the vent to a more open condition, to prevent occlusioneffect discomfort. 12.
158 FONIX 7000 Hearing Aid Analyzer 6.5.2 Choosing a speech weighting By default, the Digital Speech (and Composite) signal uses the ANSI S3.42 speech weighting. Some clinicians, however, prefer to test using the ICRA speech weighting, which was used in the development of some digital hearing aids.
Real-Ear Measurements 159 2. Select the Digital Speech signal source with [F5]. 3. Press [MENU] to enter the local menu. 4. Select Bias Tone under Source using [∨, ∧]. 5. Use [<, >] to select the level of the bias signal. Choose from 40-90 dB SPL in 5 dB steps. 6. Press [EXIT] to return to the measurement screen. The Digital Speech signal will now include the pure-tone bias signal. 7. Press [START] to start the measurement. 8. Use [<, >] to change the frequency of the bias signal.
160 FONIX 7000 Hearing Aid Analyzer 5. Press [START] to measure the frequency response of the hearing aid. Press [STOP] when the measurement has stabilized. 6. Use [F2] to select the REAR 3. 7. Use [F5] to select Composite. 8. Use [∨, ∧] to set the source amplitude to 65 dB SPL. 9. Press [START] to start the measurement. After the measurement has stabilized, press [STOP] to stop the measurement. Figure 6.5.4 illustrates an example of a digital hearing aid with noise suppresion.
Real-Ear Measurements 161 4. Press [LEVEL] to level the sound field speaker. 5. Use [F2] to select REUG 1. (Press [F2] to open the pop-up selection menu. Use [∨, ∧] to select REUG 1. Press [>] to complete the selection and close the menu.) 6. Use [F5] to set the source type to DIG SPEECH. 7. Use [∨, ∧] to set the source amplitude to 50 dB SPL. 8. Press [START] to start the frequency response measurement. When the measurement has stabilized, press [STOP]. This is the “reverse” measurement curve.
162 FONIX 7000 Hearing Aid Analyzer 14. Press [START] to start the frequency response measurement. (The “reverse” measurement will reappear when the measurement starts.) When the “forward” measurement has stabilized, press [STOP]. 15. Look at the difference between the “forward” (REAG 2) and the “reverse” (REUG 1) frequency responses (Figure 6.6.1). The “forward” frequency response should show more amplification than the reverse frequency response.
Real-Ear Measurements 163 7. Test as usual. With the reference microphone disabled, it is even more critical than usual that the patient not move after leveling and that the sound field be undisturbed during testing. 6.8 Visible Speech The Visible Speech screen, shown in Figure 6.8, is a special screen used for performing real-ear measurements with live speech or other external source types. The following features are displayed upon the Visible Speech screen before the test has started.
164 FONIX 7000 Hearing Aid Analyzer Figure 6.8—Visible Speech screen before a measurement is taken. The shaded regions are below and above the patient’s thresholds and uncomfortable levels. The L, M, and H lines reppresent the real-ear targets at 50, 65, and 80 dB SPL. The l, m, and h lines represent the region of unamplified speech. 6.8.1 Performing Visible Speech measurement 1. Enter the patient’s audiogram into the analyzer, as described in Section 6.3.1. 2.
Real-Ear Measurements 165 6.8.
166 FONIX 7000 Hearing Aid Analyzer Figure 6.8.3—Completed Visible Speech test. 6.8.4 Measuring multiple envelopes The clinician can measure up to three different Visible Speech envelopes. For example, it may be beneficial to perform measurements of the different programs on the hearing aid. Another example of the usefulness of multiple measurements is when using the voice of the spouse of the patient. Have the spouse stand a few feet from the patient when measuring Visible Speech Envelope 1.
Real-Ear Measurements 167 6.9 CROS/BICROS Aids When performing real-ear measurements on a Body aid, CROS, or Bi-CROS aid, we suggest the following setups and procedures. Four Goals: 6.9.1—Measuring the Head Baffle Effect 6.9.2—Measuring the Overcoming of the Head Baffle Effect 6.9.3—Measuring the Overall Insertion Gain 6.9.
168 FONIX 7000 Hearing Aid Analyzer 6.9.1 Measuring the Head-Baffle Effect The measurements described in this section are for both CROS and BI-CROS hearing aids. Unaided—Real Ear response on “bad ear” side Set up the 7000 test system as follows.
169 Real-Ear Measurements 6.9.2 Measuring the Overcoming of the Head-Baffle Effect This section describes how to measure how well the hearing aid overcomes the head-baffle effect. The methods are different for CROS hearing aids than they are for BICROS hearing aids. 6.9.2.1 CROS Unaided—Measurement of “good” ear canal (baffled by head) Set up the 7000 test system as follows.
170 FONIX 7000 Hearing Aid Analyzer 6.9.2.2 BI-CROS Unaided—Measurement of “better” ear canal (baffled by head) Set up the 7000 test system as follows.
171 Real-Ear Measurements 6.9.3.1 CROS Unaided—Measurement of “good” ear Set up the 7000 test system as follows. GOOD EAR • Reference microphone ON BAD EAR • Sound field LEVELED • Reference microphone over pinna of bad ear • Probe microphone inside unoccluded ear canal of good ear PROBE MIC • Loudspeaker at 0º, 12 inches from bridge of nose 12" REFERENCE MIC SPEAKER Aided—Measurement of “good” ear Same setup as above, except: • Aid in place in good ear and set to user gain.
172 FONIX 7000 Hearing Aid Analyzer 6.9.4 Measuring Insertion Loss to the “Good” Ear (CROS) The method for measuring insertion loss in the patient’s “good” ear is described in this section. They are the same for CROS and BICROS hearing aids. When a CROS aid has been prescribed to overcome a severe unilateral high-frequency loss, you may want to ensure that inserting an open ear mold into the good ear has not significantly attenuated the acoustic transmission to the good ear.
Appendix A 173 Specifications ACOUSTIC DRIVE SIGNAL Frequencies: Composite: 200 to 8000 Hz in 100 Hz intervals SINE: 200 to 8000 Hz 1/12 oct, nearest 100 Hz intervals Frequency Accuracy: 1% Amplitute (RMS 5-dB steps) Chamber Sound Field Amplitude Accuracy COMPOSITE: 40 to 100 dBSPL; SINE: 40 to 100 dBSPL COMPOSITE: 40 to 90 dBSPL; SINE: 40 to 90 dBSPL Within 1 dB from 300 to 5000 Hz, all others within (All Modes, M1950E only) 3 dB; after leveling CREST FACTOR Composite Mode Signal: Less than 12 dB
174 FONIX 7000 Hearing Aid Analyzer SPECTRUM MODE AVERAGING Spectral : off, 2,4,8 and 16. HARMONIC DISTORTION ANALYZER Type: Selectable for 2nd, 3rd, Total (2nd plus 3rd), or none. Resolution: 0.1 percent. Reading: Percent (%) with respect to fundamental. Single frequency readings made at 100-Hz intervals from 200 through 2600 Hz. Sweep readings made at 100 Hz intervals from 400 through 1900 Hz. ATTACK/RELEASE TIME Range: 1.25 to 5000 mSec.
175 Specifications ELECTRONICS MODULE Color: Blue module case, white front panel and gray bezel Size: 17.4"W x 6.5"H x 14.6"D (44.2 x 16.5 x 37.1 cm). Weight: 17 lbs.(7.7 kg). PRINTER, INTERNAL Type: High speed line thermal printer Paper width: 4.41" (112 mm) Print speed: 80 mm/ s PRINTER, EXTERNAL (PRINTER NOT PROVIDED) Port: 25 pin D, female Type: HP compatible, Epson Stylus series Language: HPCL3 and ESC-P/2 TEST CHAMBER Type: FONIX FC 7020 Test Area: 7"x 7.5"x 1.5 deep (17.8 x 19.
176 FONIX 7000 Hearing Aid Analyzer Ear Level Adapter: (044-1007-00) Per requirements of ANSI S3.22-1996 for adapting ear level aids to the HA-2 coupler. Sound Chamber Cable: (119-0204-07) Battery Pills #13: (059-2005-02) #675/76: (059-2004-02) #312: (059-2006-02) #10A/230: (059-2010-01). All with 12" cables—24" cables available on request. Roll of Printer Paper (026-0006-00) Operator’s Manual: (010-0019-00) OPTIONAL ACCESSORIES Video Display Monitor: (058-0077-00) VGA, flat panel, 15", color.
Appendix B 177 Calibration B.1 Calibrating the microphones To calibrate the 7000 Test System’s microphones, you will need a sound level calibrator such as the Quest CA-12, the 14mm-to-1 inch microphone adapter provided with your 7000 Test System, and a small flathead screwdriver. If you are calibrating the probe microphone, you will also need the probe microphone adapter and a Phillips-head screwdriver. Figure B.1A—Equipment for calibrating the 7000 microphones.
178 FONIX 7000 Hearing Aid Analyzer 6. If necessary, adjust the gain of the 1950E microphone by using the flathead screwdriver to adjust the “gain” pot on the back of the 7000 Test System next to the microphone connector. Match the levels as close as possible. If you are unable to adjust the gain of the microphone to the level emmited by the calibrator, you probably have a faulty microphone and should contact your local FONIX distributor or the Frye factory. Figure B.
179 Calibration Figure B.1.C—Adjusting the reference pot with a Phillips-head screwdriver. 5. Remove the reference microphone from the adapter and turn off the calibrator. 6. Attach a new probe tube to the probe microphone. 7. Thread the probe tube through the edged side of the probe microphone adapter so that the probe tube sticks out a couple of millimeters from the other end of the adapter. See Figure B.1D. Figure B.1D—Calibrating the real-ear probe microphone 8.
180 FONIX 7000 Hearing Aid Analyzer 10. Turn on the sound level calibrator and look at the “Probe Mic” level in the Microphone Calibration window. It should match the calibrated tone emitted by the sound field calibrator. 11. If necessary, adjust the gain of the probe microphone by using the Phillipshead screwdriver to adjust the “probe” pot on the back of the remote module of the 7000 Test System. Match the levels as close as possible.
181 Calibration Figre B.
182 FONIX 7000 Hearing Aid Analyzer
Appendix C 183 Troubleshooting Guide These are the most common problems that typically cause instrument failure. Please check these troubleshooting suggestions and follow the procedures outlined in this manual before contacting your local service representative or Frye Electronics. General Problems: No power a. Check ON switch(s). b. Make sure the the power cable is plugged into a working wall outlet. c. Check the fuse in the power entry module. CRT/VGA/LCD display monitor is not working a.
184 FONIX 7000 Hearing Aid Analyzer Coupler Problems: 1. HA-2 Coupler (BTE) adapter tubing is missing, loose, or cracked Replace with #13 thickwall tubing. Length: 0.6" (15mm). 2. Test microphone is difficult to get into coupler or the ear level adapter does not easily seal to the other end of the coupler Lubricate the black “O” ring with light petroleum type lubricant. 3. A bump or peak in the low frequency response curve a. There may be a hearing aid vent leak. Be sure to Fun-Tak the vent. b.
Appendix D 185 The FONIX CIC Feature Background Zwislocki built an ear simulator coupler years ago to better approximate the real ear’s impedance variation with frequency. The ear’s volume appears to get larger at lower frequencies. Mahlon Burkhard at Industrial Research Products agreed with this approach, especially when they built the KEMAR, and designed an ear simulator that had impedance changes that matched the Zwislocki figures.
186 FONIX 7000 Hearing Aid Analyzer a good hearing aid fitting. It also felt that the approach taken in the use of the MZ coupler has been well accepted by professionals throughout the world and that the new CIC coupler should use a similar approach, with response corrections modified to take the smaller CIC volume into account. The Basic Problem The ear is not a simple structure. It is a biological coupling device that converts sound energy to nerve impulses.
The FONIX CIC Feature 187 Knowing the physical volume of the occluded ear canal and its frequency response variations, it is possible to calculate the equivalent volume of the TM itself at each frequency and to apply this figure to the response of the 0.25 cc cavity between the hearing aid and the TM. When the calculated volume variation of the TM is applied to the smaller volume of the CIC coupler, the total response variation comes out to be from -8.6 dB at 200 Hz to +5.
188 FONIX 7000 Hearing Aid Analyzer CIC CORRECTION FACTORS dB Hz dB Hz dB Hz dB Hz -8.7 200 -0.95 2200 3.2 4200 4.54 6200 -8.6 300 -0.5 2300 3.3 4300 4.55 6300 -8.7 400 -0.2 2400 3.5 4400 4.6 6400 -8.75 500 0 2500 3.6 4500 4.65 6500 -9 600 0.3 2600 3.7 4600 4.7 6600 -8.9 700 0.5 2700 3.8 4700 4.75 6700 -8.8 800 0.7 2800 3.85 4800 4.8 6800 -8.2 900 1 2900 3.95 4900 4.85 6900 -6.55 1000 1.2 3000 4 5000 4.9 7000 -6 1100 1.
Appendix E 189 Fitting Formula Tables The conversions used by the FONIX 7000 Test System to convert audiograms to target gain curves are the following: NAL-RP FITTING FORMULA CALCULATION The insertion gains at each frequency are calculated according to the following formulas: Freq (Hz) Insertion Gain (dB) 250 500 750 1000 1500 2000 3000 4000 6000 8000 X + .31 HTL - 17dB + S X + .31 HTL - 8dB + S X + .31 HTL - 3dB + S X + .31 HTL + 1dB + S X + .31 HTL + 1dB + S X + .31 HTL - 1dB + S X + .
190 FONIX 7000 Hearing Aid Analyzer POGO Prescription of Gain/Output (POGO) for Hearing Aids by: Geary A. McCandless, PhD, & Poul Erik Lyregaard, MSc Hearing Instruments vol 34 #1, 1983 Required insertion gain is calculated as follows: Frequency (Hz) * * * * 250 500 750 1000 1500 2000 3000 4000 6000 8000 Insertion Gain (dB) 1/2 1/2 1/2 1/2 1/2 1/2 1/2 1/2 1/2 1/2 HTL - 10 dB HTL - 5 dB HTL - 2.
191 Fitting Formula Tables 1/3, 1/2, 2/3 Gain The 1/3-2/3 Insertion Gain Hearing Aid Selection Guide by: Robert Libby Hearing Instruments vol 37 #3, 1986 Required insertion gain is calculated as follows: FREQ.
192 FONIX 7000 Hearing Aid Analyzer
Appendix F 193 Probe SPL Mode Description The Target IG is converted to the Target SPL in the following steps: (Conversion tables appear on the following pages.) 1. Add the source level for Aided curve 2. 2. Interpolate from 10 frequency to 79 frequency curve frame. 3. Add the AVG Unaided ear response REUR in Table 1. 4. If Aided 2 is composite, subtract 10.7 dB from each frequency. If Aided 2 is Speech Weighted tone, add 2.1 dB to each frequency. 5.
194 FONIX 7000 Hearing Aid Analyzer TABLE 1 Average Real-Ear Unaided Response (REUR) FREQ (Hz) GAIN dB FREQ (Hz) GAIN dB FREQ (Hz) GAIN dB FREQ (Hz) GAIN dB 200 300 400 500 600 700 800 900 1000 1100 1200 1300 1400 1500 1600 1700 1800 1900 2000 1.6 2.1 2.7 2.9 2.9 3.1 3.3 3.6 3.4 3.1 3.6 4.2 4.4 5.6 7.0 8.1 9.3 10.9 12.6 2100 2200 2300 2400 2500 2600 2700 2800 2900 3000 3100 3200 3300 3400 3500 3600 3700 3800 3900 4000 13.9 14.7 15.1 15.0 15.1 15.0 14.6 14.1 13.6 13.7 13.8 14.1 14.5 14.8 14.
195 Probe SPL Mode Description TABLE 3 HL to real-ear SPL (or SPL to HL) conversion table from ANSI S3.6-1989 Table G.1 FREQ (Hz) 250 500 750 1000 1500 2000 3000 4000 6000 8000 dB 19.0 12.0 10.5 9.0 9.5 15.0 15.5 13.0 13.0 14.
196 FONIX 7000 Hearing Aid Analyzer
Appendix G 197 Glossary of Terms AGC Automatic Gain Control (or Automatic Volume Control). A feature on a hearing aid that automatically adjusts the gain, depending either on the input level (AGC-I) or the output level (AGC-O). Also known as “Compression.” AIDED RESPONSE The response of a hearing aid in place on the ear. (Also called “In-situ Response.”) Subtract the “Unaided Response” from the “Aided Response” to get the Insertion Gain Response.
198 FONIX 7000 Hearing Aid Analyzer BICROS A CROS aid that has two microphones, one at each ear, sending both signals to one ear. BLOOMING EFFECT A characteristic of pure tone testing at high levels, that typically shows low frequencies being amplified more than they are under normal use conditions. CALIBRATOR A sound generator that produces a tone at a precisely controlled frequency and amplitude. CHAP Computer Hearing Aid Program.
Glossary of Terms for the FONIX 7000 199 DATA In FONIX analyzers, the word “data” refers to displaying curve information as a table of numbers. DEFAULT A choice automatically made by a computer program. DIN CONNECTOR A European-standard connector with pins surrounded by a round metal shell. DISTORTION Elements of a reproduced sound that deviate from the original. DSIN Digital speech-in noise. The source signal used for testing digital aids. The ANSI and ICRA speech weightings are available.
200 FONIX 7000 Hearing Aid Analyzer GIFROC The inverse of “CORFIG.” GIFROC is the transformation that, when added to a coupler response, will give the estimated insertion-gain response. GRAPH A grid of lines, with the vertical lines representing one set of information and the horizontal lines representing another. A “Curve” superimposed on a graph grid, gives information about test results. HAIC Hearing Aid Industry Conference. HARMONICS Integral multiples of a pure tone.
Glossary of Terms for the FONIX 7000 201 INTERMODULATION DISTORTION Distortion generated by the faulty mixture of different input frequencies. This is a primary cause of harshness and lack of intelligibility in a hearing aid. INVALID In the Multi-Curve Option, this word appears when there is no curve stored in a selected memory location. JIS Japanese Industrial Standard. The organization which sets standards for measurements in Japan. KEMAR Knowles Electronics Manikin for Acoustic Research.
202 FONIX 7000 Hearing Aid Analyzer POWER The output of an aid, in dB SPL. PROBE MICROPHONE A miniature microphone with a thin, flexible tube that is inserted into an ear canal to measure sound. PT BURST A burst of ten pure tones corresponding to standard audometric frequencies. The entire signal lasts for less than two seconds. PURE TONE A testing tone consisting of only one frequency.
Glossary of Terms for the FONIX 7000 203 RMS Root Mean Square. An overall measurement of the signal going in or coming out of a hearing aid. When measuring with Pure tones, the RMS level at each individual frequency will be the same as the level shown at each frequency on a response curve. When measuring with a Composite Tone, the (overall) RMS level will be several dB higher than the level at each frequency on a response curve, since all the frequencies are presented at once.
204 FONIX 7000 Hearing Aid Analyzer WARBLE TONE A pure tone with slight, but rapid, frequency variations. WEIGHTED GAIN A measure of the amplification (gain) of an aid, using an input signal (source) that has a spectral shape similar to that of the long term average of speech. WEIGHTED POWER The measurement of amplitude, in SPL, of the output of an aid, using an input signal (source) that has a spectral shape similar to that of the long term average of speech.
205 FONIX 7000 Hearing Aid Analyzer Index A Adaptive AGC 36 AGC frequency 116 AIDED DATA 153 Aided response 148 Aid type 95 ANSI 84, 158 ANSI 03 107, 108, 110 ANSI 92 117 ANSI Option 3 Arrow keys 12, 28 Attack & Release test 104 Attack Window 116 Audiogram 135 Automatic 151 Automatic testing 91 Average 73 Average unaided response 147 Avg Freqs 95 Azimuth 128 B Battery 100 Battery current drain 77 Battery Meas 96, 115, 122, 125 Battery Size 96, 115, 122, 125 Battery substitution pills 5, 9 Bias signals 85
206 E Ear-level adapter 4, 59 Ear hook 7, 129 Enhanced DSP 97 Equiv Noise Test 115, 122, 126 EXIT 12, 28 Eyeglass 65 F Factory 22 FAST 33, 69 FEED 12, 28 Fitting formula tables 189 Fitting rules 150 FM kit 10 Frequency 151 Frequency sweep 69 Front panel layout 11 Fully-automatic 151 Fully-automatic mode 93 Function keys 11, 23 G Gain 147 Glossary 197 GRAPH 153 Graph scale 94 Group delay 97 H HA-1 4, 59 HA-2 4, 59 Harmonic distortion 36, 74 Head-baffle effect 168 Headband 8 Hearing aid setup 58 HELP 12 His
207 Index Noise reduction 35, 38, 88 Noise Red (Comp) 95 Noise Red (Tone) 95, 115, 122, 125 Noise suppression 84, 86, 88, 159 NORMAL 33, 69 O Occluded ear simulator 89 Occlusion effect 156 OES 89 OES Option 3 Open ear 62, 162 Option 115 OSPL90 115 Output 147 Output limit 156 Output limiting 156 Output Trans 95 P Phase 98 Powering 19 Prescription targets 150 PRINT 12, 28 Printer 96, 116, 120, 123, 126 choice 42 error messages 44 external 48 internal 44 label 43 loading 45 Printing 42 Print Label 96, 116,
208 Specifications 173 Speech mapping. See live speech mapping Speech weighting 158 SPL 145, 147, 149, 150, 193 START 12, 28 Static test 101 Static Tone 95 STOP 12, 28 Sweep Meas.
