FONIX® FP40/FP40D PORTABLE HEARING AID ANALYZER OPERATOR’S MANUAL A Note on this Manual The instructions in this manual are for software version 3.70 and above, with references to earlier software. However, you may contact Frye Electronics for a more appropriate manual if you have earlier software. Software Version 3.70 © September 2005 Frye Electronics, Inc. Rev. Jun. 04, 2007 All Rights Reserved.
Table of Contents Chapter 1: Introduction 1.1 Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1.2 Hardware History . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1.3 Features & Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.3.1 Composite/Digital Speech Option . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.3.2 Customizing the function keys . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 2.4 Source Types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.4.1 Understanding Pure-tone signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.4.1.1 Pure-tone settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.4.1.2 Noise Reduction. . . . . . . . . . . . . . . . . . . . . . . . .
3.4.6 3.4.7 3.4.8 3.4.9 Viewing harmonic distortion. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Viewing battery current drain. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Switching between gain and output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Testing with the reference microphone. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 46 46 46 3.5 Digital 3.5.1 3.5.2 3.5.3 Aids . . . . . . . . . . . . . . . . . . . . . .
Chapter 5: Real-Ear Measurements 5.1 Preparation for Real-Ear Measurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.1.1 Setting up the analyzer for testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.1.1.1 To set up the microphones and monitor headset . . . . . . . . . . . . . . . . . . . . 5.1.1.2 To set up the internal sound field speaker. . . . . . . . . . . . . . . . . . . . . . . . . 5.1.1.3 To set up an external sound field speaker . . . . . . . . . . .
5.8 Miscellaneous . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.8.1 Single frequency response . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.8.2 Smoothing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.8.3 Reset Level . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.8.4 Data Display . . . . . . . . . . . . . . . . . .
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Chapter 1: Introduction 1.1 Description Hearing aid analyzers are designed to give the user accurate information on how much amplification the aid provides, which frequencies it amplifies, how loud it can get, and how much distortion and noise are present. Information is displayed in both graphs and in number tables, and can be printed as desired. The FP40 Hearing Aid Analyzer is the third generation of portable analyzers manufactured by Frye Electronics.
Also in 1994, we introduced the FP40-D desk model analyzer. This unit is always equipped with the real ear testing function. In order to minimize costs, the Battery Pack Option is not available on this unit and some accessories (battery pills and monitor headset) that are standard on the FP40 are optional with the FP40-D. Since this unit does not have a lid, a separate soft carrying case is available for those who want to carry the unit from place to place.
The use of the Composite or Digital Speech signals can uncover the presence of intermodulation distortion in a hearing aid. Intermodulation distortion is the distortion that results when two or more frequencies are delivered to the hearing aid simultaneously, resulting in the addition of frequencies to the output that were not present in the input.
1.3.5 ID Option The ID Option personalizes the printout strips with the owner’s name and address or phone number. Specify two lines of 27 characters each at time of purchase, and we will program them into your instrument. The ID can be changed for a modest fee with an exchange of PROMs (Programmable Read Only Memory). 1.3.6 RS232 Option The RS232 Option allows you to hook your analyzer up to a computer so you can grab your analyzer data from your analyzer and save it on your computer.
1.4 Accessories The standard and optional accessories available for the FP40 analyzer are described in this section. 1.4.1 Standard Accessories Microphone Adapter 14 mm to ANSI 1" diameter microphone size. This is used for calibrating the FP40 microphones. HA-1 2-cc Coupler Dimensions per requirements of ANSI S3.7 for testing in-the-ear aids. HA-2 2-cc Coupler Dimensions per requirements of ANSI S3.7 for testing ear level, eyeglass and body aids. Ear-Level (BTE) Adapter Snaps into the 1/4" (6.
FM40 Microphone Provided if the Real-Ear Option is not ordered. Battery Pills (With 12" [30 cm] cables — 24" [60 cm]) cables available upon request) #13, #675/65, #312, #10A/230. (All pills optional with FP40-D). Operator’s Manual 1.4.2 Optional Accessories 6-CC Coupler Per ANSI S3.7 for NBS 9A—used to check output of audiometers.
6040 Sound Chamber For control of external noises. External Telecoil For checking the response of aids in the “telephone” mode. Open Ear Coupler CIC Coupler Required coupler for use with CIC Option. Non-standard coupler used for realistic testing of open ear hearing aids. RECD Earphone Package Consists of one ER3A earphone with a phono plug, a 72 inch cable, an assortment of ear tips, a calibration certificate, and a lapel clip.
Child Size Wedge Style Earhook Holds probe and reference microphones during real ear testing. Telewand For checking the telecoil response per ANSI-S3.
Wedge Style Ear Hook Standard size Holds probe and reference microphones during real ear testing. Improved design eliminates need for Velcro headband. Optional Swing Arm, Speaker, and Cable Allows precise placement and aiming of the loudspeaker. Monitor Headset, folding (Optional with FP40-D) Infant/Child Headband Package Includes infant, child, and adult headbands, six flexible earhooks, and two sets of “animal ears.
1.5 Layout & Controls This section gives a short explanation of the layout of the FP40 analyzer, its controls, and its functions 1.5.1 LCD (Liquid Crystal Display) The FP40 is equipped with an LCD screen that displays test results and operational instructions in both alphanumeric and graphical formats. This display is mounted on a swing-up door that can be adjusted for optimum viewing by the operator.
1.5.2 Front Panel Buttons There are nine function key buttons in the top row of the FP40 front panel. The function of each of these keys changes as you move from screen to screen on the FP40. The rest of the front panel buttons have specific functions that do not change with each new menu selection. Feed Feeds the paper through the printer. Print Produces a hard copy of the data and graphs displayed on the LCD screen or monitor screen.
1.5.4 Front Panel Knobs Amplitude Controls the amplitude or loudness of the test signal. Is also used to move the cursor up and down in making menu selections. Frequency Controls the frequency of the test signal in pure-tone mode. Is also used to move the cursor left and right when making menu selections. In the real-ear target screen, it selects the amplitude in the audiogram tables. Contrast Control Controls the contrast of LCD display. If no display appears, check this control first.
1.5.6 Right Side Mounted Jack and Module Line input connector, IEC computer variety. Dual “snap in” fuse holder. Instrument will automatically choose the proper voltage. 1.5.7 Sound Chamber Mounted Jacks and Controls Jacks Battery replacement pill jack. Microphone jack. Controls Gain controls for microphones. Found on the left side of the sound chamber, near te speaker. Marked: Probe Gain and Ref. Gain. 1.5.8 Top of Instrument, Printer Printer Door Paper Release Lever Figure 1.5.
1.6 FP40 Setup This section describes how to set up the FP40 analyzer and prepare it for testing. 1.6.1 Setting up the instrument Unpack and locate all accessories (in the lid/FP40; in the boxes/FP40-D). Save the shipping box in case you need to send the unit in to us for repair or major upgrades. Choose a location for the FP40 which is relatively free of ambient sounds and vibrations. See Figure 1.5.5 for a drawing of the rear panel 1.6.
If desired, plug in an external video monitor to the connector labeled “Video Monitor” on the back of the FP40. You can also plug in an external sound chamber or an external sound field speaker into the “external speaker” jack of the FP40. Hint: When something is plugged into the external speaker jack, the sound source of the FP40 is always delivered to that external source, regardless of whether you are performing a coupler test or a real-ear test. 1.6.
1.7.3 Emergency Shutdown If you find it impossible to turn off the instrument using the OPERATE button in units with a Battery Option, hold OPERATE down and then tap RESET twice. Or you can simply hold the OPERATE button down for five seconds. 1.7.4 Warranty The FONIX FP40/FP40-D and its accessories are guaranteed to be free from manufacturing defects which would prevent the products from meeting these specifications for a period of one year from date of purchase.
Chapter 2: General Operation This chapter discusses the general operation of the FP40 analyzer. You will learn how to navigate through the different screens, use the General Setup Menu, and change the function keys to suit your purposes. Other general operational topics will also be discussed such as source types, battery pills, printers, and other topics. 2.1 Screen Navigation You move through the different screens of the FP40 by using the function keys.
2.2.1 Making selections Notice the three columns in the General Setup Menu. Move the selection indicator (lines above and below the selection) from one column to another using the FREQUENCY knob. Move the knob slowly. You will feel each position change. Move the selection indicator up and down within the columns with the AMPLITUDE knob. Push the START/STOP button, found in the very center of the front panel, to switch between the available choices at the indicated position. 2.2.
2.3 Using Function Keys The front panel of the FP40 analyzer contains nine function keys, F1 through F9. These keys control the navigation through the FP40 screens as well as some settings in each screen. 2.3.1 Hints The first thing you need to understand when working with the FP40 is the concept of “function keys.” In order to make it easier to add new functions and screens to the FP40, we made the function of keys F1 through F9 vary, depending upon the current screen and your current settings.
Figure 2.3.1—The Main Coupler Screen Notice that F1, F4, and F5 are written in large letters. They take you to the Menu, ANSI 96, and Probe Screens, respectively. F2, F3, F6, F7, and F9 are all settings that pertain to the current Main Coupler Screen. 2.3.2 Customizing the function keys As described in Section 2.3.1, the functions of F1 through F9 will vary, depending upon the current screen. Most of the time, the functions of these keys in each screen are set at the factory and cannot be changed.
Note: If you toggle a function with SETUP F2 or SETUP F3, that function will remain in that setting until you explicitly change it back or turn off the analyzer. For example, if you were to: 1) Choose MULTICURVE for SETUP F2, 2) Turn MULTICURVE ON using the F2 button in the General Setup Menu, 3) Choose CIC for SETUP F2, then Multi-Curve would remain ON in the Main Coupler Screen even though it would no longer be the selection for SETUP F2.
2.4.1.1 Pure-tone settings There are several different settings available in the General Setup Menu for pure-tone signals. Here is an explanation of those settings. RESET FREQ: The frequency the analyzer returns to when RESET is pressed. NOISE REDUC: The amount of noise reduction used in pure-tone measurements. See Section 2.4.1.2. SETTL. TIME: The amount of time each tone is presented before the measurement is made. See Section 2.4.1.3.
In determining the length of time needed for the proper measurement, a good rule is to use twice the published attack time of the hearing aid. If you are unsure of the attack time, you can experiment with longer times and shorter times and see if there is any difference in the test results. Linear aids can be tested very quickly, so a delay of 20 mS is usually fine. Other aids are quite variable. 2.4.1.
Digital Speech ANSI uses the same speech spectrum as the Composite signal. This speech spectrum, taken from the ANSI S3.42 standard, rolls off the high frequencies starting with 3 dB down at 900 Hz and continuing at a rate of 9 dB per octave. Digital Speech ICRA uses the ICRA speech spectrum developed by the International Collegium of Rehabilitative Audiology. The ICRA spectrum is based on the Long Term Average Speech Spectrum (LTASS) and rolls off the high frequencies more rapidly than the ANSI spectrum.
This type of distortion is only apparent when a composite signal source is used because pure-tone sweeps do not present more than one frequency at a time. Figure 2.4.2.3—IM distortion 2.4.2.4 Composite source levels When you adjust the amplitude of a composite signal, you are adjusting the root-mean-square (RMS) of the signal, not the amplitude of the individual frequency components. None of the amplitudes individual frequency components will be as high as the amplitude of the overall signal.
2.5 Display Mode Although the FP40 comes standard with an LCD screen, it is easy to hook up an external monitor for a larger, more colorful display. To attach the video monitor: Hook a standard computer monitor to the port labeled “Video Monitor” on the back of the FP40 analyzer. To view with the video monitor: • Press F5 from the Opening Screen of the FP40 analyzer. This is the screen that appears only when you first turn on the analyzer.
To turn on the battery current drain measurement in the Main Coupler Screen: 1. Press F1, MENU, from the Main Coupler Screen. 2. Select BATTERY DISP in the third column of the screen, under COUPLER SETTINGS. 3. Press START/STOP to toggle ON. 4. Press F1 to exit back to the Main Coupler Screen. You should now see a battery current reading under the Status Box. See Figure 2.6B. 5. Press F7 to select the battery pill that you are using. To set the default battery pill: 1.
2.7 Using the DATA button Although it’s usually more useful to display test results in the familiar graph format, it can often be useful to look at the actual numerical data. You can do this in the Main Coupler Screen or in the real-ear measurement screens. To switch back and forth between graphical and numerical data format, press the DATA/GRAPH button on the FP40 main panel. See Figure 2.7. Figure 2.7—DATA coupler screen Notes: • Only one measurement curve can be displayed in numerical format at a time.
To use an external sound chamber or an external speaker, plug it into the jack labeled “external speaker” on the back of the FP40. Hint: Whenever you have an external sound source plugged into the external speaker jack on the FP40 analyzer, all sound from the analyzer goes to the external sound source, no matter what operational screen you are viewing. To avoid confusion, unplug the external sound source when it’s not in use. 2.
• If the print head is up, you will see the message PLEASE PUSH LEVER NEXT TO THE PRINTER. To correct this, push the black lever to the left of the thermal printer. To change the paper: 1. Remove the printer door by pushing the small black knob on the printer door to the right. 2. Remove the paper roller. 3. Place the new paper roll on the roller and insert it into the paper slot. Refer to the drawing on the inside of the printer door. 4.
the External Printer Package from Frye Electronics containing a custom cable (PN 119-0312-00), a series-to-parallel converter, and a printer cable. The FP40 will work with all new HP LaserJet printers, and with many Deskjet printers (check language specifications in the printer manual). Also, the Epson FX-870, FX-880, and FX-1170 printers are compatible. If the printer uses PPA (Printer Performance Architecture) it will be incompatible with FONIX instruments.
2.10 The Opening Screen The Opening Screen of the FP40 (Figure 2.10) contains some useful information including: • Software version of your analyzer, • Option code of your analyzer, • RS232 availability, • Frye Electronics contact information. In the Opening Screen, you can turn on and off the screensaver, and switch from LCD to VGA display mode. The screensaver turns off the LCD backlighting if the unit hasn’t been used in 15 minutes. You can deactivate it by pressing any key. Figure 2.
You may still be able to operate when the gauge shows empty, but you are on reserve. Battery operation shuts down when the battery voltage reaches approximately 10 volts. If the software fails and the battery discharges to 9.2V, there is an automatic hardware shutdown to protect the batteries. Be sure to recharge the batteries within 24 hours if the instrument shuts down (having reached 10V), to prevent damage to the batteries.
Chapter 3: Coupler Measurements The Main Coupler Screen is the first operational screen you encounter when using the FP40. In it, you can take coupler frequency response curves and view them in either dB GAIN or dB SPL. By default, the FP40 comes with three different types of pure-tone sweeps that you can use as signals to generate the response curves. You can also add the Composite and Digital Speech signals for testing AGC and digital hearing aids. 3.
3.1.2 Viewing a Composite display Figure 3.1.2—Composite coupler screen 1. Display type: dB GAIN or dB SPL 2. Signal type 3. Composite weighting 4. Amount of noise reduction used (see Section 2.4.1.2) 5. Status of reference microphone 6. Leveling status 7. Source level of signal 8. RMS out measured by analyzer of current graph 9. Battery current drain (only if turned on) 3.
altered since the analyzer was last leveled, invalidating the leveling. When in doubt, level the sound chamber again. 3.2.1 Leveling without the reference microphone (standard) The leveling process described here is adequate for most testing situations. If you have the Probe Option, you can also level the sound chamber using the reference (probe) microphone. That method is described in Section 3.2.2. 1. Look in the Coupler Status Box. Make sure it says “REFERENCE MIC OFF.
1. Set up the aid for testing as described in Section 3.3. If you are using a battery pill for testing, don’t plug it in yet. If you are using a regular battery for testing, do not turn on the hearing aid. 2. Insert the measurement microphone into the coupler. 3. Place the reference (probe) microphone next to the measurement microphone. Use some FunTak to secure the probe tube next to the microphone of the hearing aid. See Figure 3.2.2. 4. Press F1 from a coupler measurement screen. 5.
3.3.1 Setting up a BTE 1. Adjust the tone and gain controls of the aid to the desired positions. If desired, insert a battery pill into the aid. 2. Insert the end of the earhook of the hearing aid into the plastic tubing of the ear level adapter. 3. Insert the measurement microphone into the HA-2 2-cc coupler. 4. Snap the ear level adapter onto the end of the coupler. 5.
3. Align the sound opening of the aid with the hole at the conical end of the coupler. Look through the open end of the coupler to be sure the sound opening of the aid is clear of obstructions and correctly placed. 4. Seal the outside opening of 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.
6. Slowly insert the microphone into the coupler. You may feel an initial resistance when the mic reaches the O-ring. Continue to push the microphone until it stops. 7. Place the completed assembly over the center of the speaker in the test chamber. With ITEs, the position of the aid can affect the frequency response. If possible, point the faceplate of the aid toward the right or the left. 8. If you are using a battery pill, be sure the metal conductor strip does not obstruct the sound path. 3.3.
3.4 Frequency responses The Main Coupler Screen lets you take the frequency response of the hearing aid. You can: • Use a variety of signal sources • View multiple responses at once • Find the single frequency response of the aid • Take a three frequency average • View the harmonic distortion in bars or in a separate table • Switch between viewing curves in output and gain • Test with or without the reference microphone This section will tell you how to do all of these things. 3.4.
Figure 3.4.1—Selecting a pure-tone sweep To select a Composite/Digital Speech source: 1. Press F1—MENU to enter the General Setup Menu. 2. Select SOURCE with the FREQUENCY and AMPLITUDE knobs. 3. Press [START/STOP] to cycle through your choices. To select the Composite signal, choose COMPOSITE. If you have the Digital Speech Option, you will also have access to DIGSP ANSI (Digital Speech ANSI) and DIGSP ICRA (Digital Speech ICRA). 4. Press F1—EXIT to return to the Main Coupler Screen. 3.4.
3.4.3 Viewing multiple measurements It’s often useful to view several different frequencies responses together on the same screen. This is especially important when testing AGC hearing aids. To do this, use the Multi-curve function. To take multiple measurements: 1. Look at the screen just above F2 and F3. If one of them is “OFF MULTICRV,” press the corresponding function button (F2 or F3) to turn it on. Skip to step 6. Otherwise, proceed to step 2 for instructions on selecting Multi-curve for F2 or F3. 2.
2. Press F1 to enter the General Setup Menu. 3. Select SOURCE with the AMPLITUDE and FREQUENCY knobs. 4. Press START/STOP to select TONE. 5. Press F1 to return to the Main Coupler Screen. 6. Open the sound chamber and listen to the signal. You will hear a continuous pure-tone signal. Close the sound chamber. 7. Look at the lower right side of the screen. You will see a box listing the SOURCE, FREQ, and MIC GAIN (or MIC SPL) of the signal. 8.
3. Use the FREQUENCY and AMPLITUDE knobs to select DISTORTION under PURE-TONE SETTINGS. 4. Press START/STOP to toggle between displaying the harmonic distortion in “bar” format on the graph or “table” format next to the graph. 5. Use the AMPLITUDE to select DIST TYPE. 6. Press START/STOP to select the type of harmonic distortion measurement to make. See Section 2.4.1.4 for more details. 7. Press F1 to return to the Main Coupler Screen. 8.
• You must position the reference microphone properly. If you don’t have the reference microphone positioned next to the microphone of the hearing aid, you will get inaccurate results. Worse, if you leave the reference microphone outside the chamber when it is turned on, you will get wildly inaccurate test results. To turn on the reference microphone: 1. Press F1 to enter the General Setup Menu. 2. Use the AMPLITUDE and FREQUENCY knobs to select REFERENCE MIC under COUPLER SETTINGS. 3.
3.5.1 Testing with Digital Speech To test digital aids with noise suppression, we have taken our standard continuous Composite signal and interrupted it at intervals just long enough to trick the hearing aid into thinking it is hearing speech instead of noise. This program is called “Digital Speech” and comes equipped with two different speech spectra: the ANSI S3.
To use the Composite signal to test high end digital aids, you first need to figure out how long you can present the signal before the aid’s noise suppression goes into effect. Follow these instructions: 1. Follow the instructions from Section 3.4.1 to select the Composite signal as the source type. 2. Use the AMPLITUDE knob to select 65 dB. 3. Press START/STOP and watch the response curve carefully.
3.6.1 Preparing for the measurement 1. Set up your analyzer so that the speaker is in the upright position. See Section 5.1.1.2. 2. Position the stand or chair you are going to use to set up the hearing aid. If you are using a chair, face the chair to the side, so that the sound field will not bounce against the large flat surface of the back of the chair. The testing surface should be about 12 inches from the speaker. 3. Use Fun-Tak to affix the large measurement microphone to the testing surface.
5. Use the AMPLITUDE knob to select an appropriate source level. Typically this measurement should be done so that it is above the noise floor of the testing environment, but below the compression knee point of the aid, if possible. If you have a quiet testing environment, use 50 dB SPL. Noisier testing environments may require you to use a higher source level to get a good measurement. 6. Press START/STOP to start the measurement. Press it again to stop the measurement once it has stabilized. Figure 3.6.
6. Press START/STOP once the measurement has stabilized. Compare the reverse measurement to the forward measurement to see the directional advantage that the aid provides. Figure 3.6.3 —Testing the reverse coupler response of a directional aid 3.7 The CIC Option The CIC Option is a way of performing a coupler test of a CIC hearing aid that more accurately reflects the real-ear performance of that aid than a regular 2-cc coupler measurement.
6. Press F2 or F3 (selected in step 3) to turn the CIC correction factors ON. 7. Test as usual. See Section 3.4.2. See Figure 3.7 for a comparison of a CIC aid tested with an HA-1 coupler and the same aid tested with a CIC coupler and correction factors. Figure 3.7—CIC vs. HA-2 comparison 3.
TYPE OF AID ITE, ITC BTE, or BODY* COUPLER COMMENT MZ-1 MZ-1 With custom earmold attached. (NOTE: Vents must be plugged.) EYEGLASS MZ-2 Without custom earmold attached, when a 3-mm horn earmold is planned, use with the Ear-Level Hearing Aid Adapter that normally snaps onto the HA-2, 2cc coupler. MZ-3 Without custom earmold attached, when a conventional #13 tubing) earmold is planned, attach a length of #13 tubing that corresponds to the length of the sound channel of the wearer’s earmold.
Chapter 4: Automated Test Sequences There are several different automated test sequences available on the FP40 analyzer: • ANSI S3.22-2003 • JIS • ANSI S3.22-1996 • ISI • ANSI S3.22-1987 • Profiler • ANSI S3.42-1992 • IEC • ACIC The ANSI S3.22 is the FDA’s hearing aid “labeling” standard. All hearing aids manufactured in the United States are labeled to this standard. ANSI 03, ANSI 96, and ANSI 87 are three versions of the same labeling standard. See Section 4.1, 4.2, and 4.3 for more information.
Here are the major differences between ANSI 03 and ANSI 96: • When you set up an AGC aid for an ANSI 03 test sequence, you will start with its compression controls set to minimum (with the compression knee point set as high as possible). Just before the input/output measurements, the test sequence will pause to allow you to set the compression controls of the aid to maximum (with the compression knee point set as low as possible).
To change the ANSI 03 settings: 1. From the ANSI 03 screen, press F1 to enter the General Setup Menu. 2. Use the AMPLITUDE and FREQUENCY knobs to select MENU TYPE. 3. Press START/STOP to choose PARTIAL. The menu will now only display the selections applicable to ANSI 03. 4. Use the AMPLITUDE and FREQUENCY knobs in conjunction with the START/STOP button to choose the settings for NOISE REDUC, SETTL. TIME, and AVG FREQS under PURETONE SETTINGS. These settings are explained in Section 2.4.1. 5.
4.1.3 Running the test sequence 1. Level the sound chamber if necessary. See Section 3.2 for details. 2. Set up the aid for testing. See Section 4.1.1. 3. Close the sound chamber. 4. Press START/STOP when you are ready to begin the test. 5. Wait for several tests to be run. For most aids, the analyzer will pause after performing several measurements in order for you to turn down the gain of the aid. 6.
8. SPA/HFA FOG: Three frequency average of a full-on gain measurement at 50 dB SPL 9. REFTG TARGET and MEASURED: The calculated reference test gain and the actual measured reference test gain 10. EQ INP NOISE: Equivalent input noise 11. RESP LIMIT and F1 and F2: The response limit level and the two frequencies where the response curve crossed over this level 12. THD: The total harmonic distortion measurements 13. HFA-SPLITS: The three frequency average of the telecoil SPLITS curve 14.
• Set the aid for the widest frequency response range. • Set AGC aids to achieve greatest possible compression. • Make sure the gain control of the aid is full-on. Follow the instructions from Section 3.3 to set up the aid in the test box for testing. 4.2.2 Setting up the analyzer for testing To enter the ANSI 96 screen: 1. From the Main Coupler Screen, look at the FP40’s display above the F4 function key. If it says “AN96,” skip to step 6. 2. Press F1 – Menu. 3.
9. Use F5 to turn ON or OFF the telecoil measurement. The ANSI 96 telecoil measurement requires the Telewand. 10. Press DATA/GRAPH if you are testing an AGC aid. This will change the function key labels. Otherwise, skip to step 14. 11. Press F2 to choose a frequency and press F3 to select whether or not you want to run an input/output (I/O) curve at this frequency. Repeat this for each of the five available frequencies. 12.
4.2.4 Viewing the results See Figure 4.2.4 for an example of an ANSI 96 test sequence (including the telecoil measurement). 1. OSPL90: Output measurement at 90 dB SPL 2. RESP50 (or 60): Response measurement at 50 (or 60) db SPL at reference test gain 3. SPLITS: Telecoil response curve measurement 4. NR: Noise reduction used in tests 5. SPA/HFA: Frequencies used for the three frequency average 6. MAX: Maximum frequency response measured and the frequency at which it occurred 7.
4.3 ANSI S3.22-1987 The ANSI S3.22-1987 standard is an older version of the ANSI S3.22-1996 standard, discussed in Section 4.2. It is still used, however, in the labeling of hearing aids designed before March 17, 2000. In ANSI 87, AGC aids are set at full-on gain for all measurements instead of being reduced to reference test gain, as they are in ANSI 96, and input/output measurements are only taken at 2000 Hz, as opposed to the five different frequencies offered with ANSI 96. 4.3.
5. Press F7 to select the battery type used in the measurements. 6. Press F8 to select whether or not you want to perform an equivalent input noise (EQIN also known as EIN) measurement. Note: The equivalent input noise measurement is difficult without a very quiet environment, especially with low gain aids. 7. Decide whether you want to test with or without the reference microphone. See Section 3.4.9 for instructions on the reference microphone. 4.3.2 Running the test sequence 1.
5. MAX: Maximum frequency response measured and the frequency at which it occurred 6. SPA/HFA SSPL90: Three frequency average of the OSPL90 curve 7. SPA/HFA FOG: Three frequency average of a full-on gain measurement at 50 (or 60) dB SPL 8. REF TEST GAIN: The measured reference test gain 9. EQ INP NOISE: Equivalent input noise 10. RESP LIMIT and F1 and F2: The response limit level and the two frequencies where the response curve crossed over this level 11. THD: The total harmonic distortion measurements 12.
4.4.1 Setting up for the test Follow the instructions found in Section 4.2.1 for instructions on setting up the aid for testing. To enter the ANSI 92 screen: 1. From the Main Coupler Screen, look at the FP40’s display above the F4 function key. If it says “AN92” , skip to step 6. 2. Press F1—Menu. 3. Use the AMPLITUDE and FREQUENCY knobs to select MAIN F4 under FUNCTION KEY DEFIN. 4. Press START/STOP to choose AN92.
4.4.3 Viewing the results See Figure 4.4.3 for an an example of ANSI 92 results. 1. NSPL90: RMS of Composite signal response curve taken at 90 dB SPL 2. FULL-ON NOISE GAIN: RMS of response curve taken with the Composite signal at 60 dB SPL minus RMS of the input signal 3. TARGET REF GAIN: Calculated reference test gain 4. ACTUAL REF GAIN: Measured reference test gain 5. CRV 5-9: Response curves at varying amplitudes 6. I/O: Input/output measurement using Composite signal Figure 4.4.3. —ANSI 92 results 4.
Follow the instructions from Section 3.3 to set up the aid in the test box for testing. 4.5.2 Setting up the analyzer for testing To enter the IEC screen: 1. From the Main Coupler Screen, look at the FP40’s display above the F4 function key. If it says “IEC” skip to step 6. 2. Press F1 – Menu. 3. Use the AMPLITUDE and FREQUENCY knobs to select MAIN F4 under FUNCTION KEY DEFIN. 4. Press START/STOP to choose IEC. This will let you use the F4 function key to enter the IEC screen from the Main Coupler Screen.
4.5.3 Running the test sequence 1. Level the sound chamber if necessary. See Section 3.2 for details. 2. Set up the aid for testing. See Section 4.5.1. 3. Close the sound chamber. 4. Press START/STOP when you are ready to begin the test. 5. Wait for several tests to be run. The analyzer will pause after performing several measurements in order for you to turn down the gain of the aid. 6.
Figure 4.5.4—IEC results 4.6 Profiler The Profiler is an automated test sequence designed to tell you all the important information about the hearing aid in a very short period of time. It was originally modeled after the ANSI 92 test sequence, but it was expanded the test to also include the most useful measurements from ANSI 87/96.
2. If you have chosen DSPA or DSPI in step 1, select the length of time each speech curve will be presented with F3. 3. Select the type of equivalent input noise measurement taken with F5. The HFA/SPA/IEC selections use a three frequency average to obtain the EIN. RMS uses a root-mean-square average to take the measurement. 4. Choose the amount of noise reduction used in the soft speech curve with F6. 5. Choose the battery type with F7. 4.6.2 Running the test sequence 1.
Figure 4.6.3—Profiler results 4.7 ACIC The ACIC test sequence is the ANSI 87 test sequence with CIC correction factors. Follow the instructions in Section 4.3 to run the ACIC test sequence. Make sure to use a CIC coupler. The ACIC test sequence is for informational puproses only. It cannot be used for comparison to manufacturer’s specifications, which assume a 2-cc coupler.
Chapter 5: Real-Ear Measurements The Probe Option of the FONIX FP40 allows you to test hearing aids in the client’s ear, also known as real-ear measurements. There are three real-ear measurement screens: Insertion Gain, SPL, and Audibility Index. Each display presents different format from which to evaluate your hearing aid fitting. There is also a Target 2-cc coupler screen that lets you take coupler measurements and compare them to appropriate targets.
Plug in the monitor headset if you want to be able to “listen in” on the sound received in the client’s ear. The monitor jack, marked “headphones” is found on the back of the FP40. The volume on the headphones is controlled with the knob next to the jack. 5.1.1.2 To set up the internal sound field speaker Remove the test box from the FP40 compartment: • Lift the compartment lid on the right side of the FP40 and remove the foam coupler holder.
speaker jack recessed channel speaker post Figure 5.1.1.2B—Upright sound field speaker Note: Do not close the chamber while it is on the post. In a closed position it may accidentally fall off. You may find it most convenient to position the FP40 at one edge of a table. If the client is seated at the side of the table, the speaker can be rotated so that the correct angle for testing is very easily achieved. See Figure 5.1.2.1.
5.1.1.3 To set up an external sound field speaker If you have a permanent location for your analyzer, you may find it more convenient to use an external sound field speaker for your real-ear measurements. This external sound field speaker can be mounted on either a floor stand or a swing arm. See Figure 5.1.1.3 for an example of the swing arm setup. When performing real-ear measurements, plug in this sound field speaker to the jack on the back of the FP40 labeled “External Speaker.” Figure 5.1.1.
Reference Mic Reference Mic Probe Mic 12" 12" Probe Mic Speaker (45 degrees) Speaker (45 degrees) Top View Front View Figure 5.1.2.1—Positioning of the sound field speaker for real-ear measurements 5.1.2.2 To place the earhook and reference microphone 1. Place the wedge-style earhook on the client’s ear. Alternately, place an earhook (without a wedge) on the client’s ear, and place the Velcro headband around the client’s head. 2.
5.1.2.3 To insert 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 (1/5 inch) past the canal opening.
Figure 5.1.2.3B – Unaided response with correct insertion of the probe tube 5.1.2.4 To level the sound field Leveling is a process that takes into consideration all the inconsistencies in the sound field. In order to get accurate measurements, it is critical that the sound field is leveled for every patient and every ear. The leveling process only uses the reference microphone placed above the client’s ear.
Figure 5.1.2.4—Leveling the sound field speaker 5.2 The Target Screen The Target screen is used to enter the patient’s threshold and uncomfortable levels, select a fitting rule, and create a target. You can modify most real-ear targets in this screen to fit the specific needs of your client. (DSL targets cannot be modified.) 5.2.1 Viewing the target screen See Figure 5.2.1 for an example of the target screen. If the target screen is entered while the realear screen is in SPL display mode (see Section 5.
WARNING: Choose OUTPUT LIMITING carefully (see procedure below). You do not want to damage your client’s hearing or cause them discomfort during testing. To ensure safety and comfort, the FP40 system reacts automatically when the OUTPUT LIMITING level is exceeded at the Probe Microphone. When the level measured at the Probe Microphone exceeds the pre-set limit, the words “PROBE OUTPUT LIMIT EXCEEDED” appear on the screen, and the program automatically stops.
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. DO NOT REUSE INSERT EARPHONE EARTIPS Insert earphone eartips are used primarily for performing RECD and audiometric measurements. Sterilization of these eartips is not possible.
Figure 5.2.1—The Target screen 1. Insertion gain target graphical display. 2. Fitting rule used in generation of the target. 3. Chosen ear. 4. UCL status: predicted or measured. 5. Age of client. 6. Frequency column. 7. HTL data for corresponding frequencies. 8. UCL data for corresponding frequencies. UCLs can be predicted or measured. 9. Insertion gain target data. (DSL LIN and DSL WDRC targets not displayed in this column) 10. HL graphical display for HTL and UCL data.
6. Use the FREQUENCY and AMPLITUDE knobs to input the hearing threshold levels for the selected ear. The numerical values will appear in the HTL dB HL column in the table just to the right of the large graph. As you enter the HTL values, the smaller graph on the right side of the screen will be updated. 7. Press F2 to highlight UCL if you would like to enter measured UCL values using the FREQUENCY and AMPLITUDE knobs.
5.2.4 Creating your own target Advanced users may want to be able to input their own targets, without applying any particular fitting rule. To do this: 1. Use F3 to select DIRECT. 2. Press F5. This will clear any existing targets and put you in a target editing mode. 3. Use the AMPLITUDE and FREQUENCY knobs to generate your own insertion gain target. (You cannot input target values in terms of dB SPL.) 5.2.5 Modifying an existing target All non-DSL targets can be modified. To modify an existing target: 1.
5.3.1 Viewing the Insertion Gain screen Here is an picture of the Insertion Gain screen. 1. Insertion gain graph 2. Source type for current curve 3. Noise reduction status for current curve 4. Reference microphone status 5. Smoothing status 6. Leveling status 7. RMS source level used to take measurement 8. RMS of the current curve. Not available with pure-tone source types. 9. Output limit status 10. Selected ear 11. Fitting rule used to create insertion gain target 12.
4. Select the desired source with F7. Use either NORM (for a pure-tone sweep), or COMP (for a composite signal). 5. Use the AMPLITUDE knob to select the desired amplitude. Unaided measurements are usually made with 65 or 70 dB SPL. 6. Press START/STOP to start the measurement. If you are using a composite source, press START/STOP again when the measurement stabilizes to stop the measurement. See Figure 5.3.2. The analyzer will automatically set itself up for an aided measurement.
6. Press F3 to select Aided 2, and repeat steps 3-5 to perform another measurement. A third aided response may be run in a similar fashion. Figure 5.3.3—The aided response Other functions • Turn on/off the display of the selected aided curve by pressing F6. • Clear all measurement curves by pressing F8. • Set the OUTPUT LIMIT under PROBE SETTINGS in the Menu screen. This sets how loud a signal the probe microphone will level without automatically shutting down the sound field speaker to protect the client.
5.3.5 Testing Open Fit Hearing Aids Open fit hearing aids have been known to interfere with the reference microphone measurement outside the ear. To determine if a particular hearing aid is interfering with the reference microphone, perform the following measurement in the insertion gain screen. The feedback cancellation and other features normally used by the patient should be enabled on the hearing aid. 1. Measure the aided response as described in Section 5.3.3.
5.4 SPL Measurements (including real-ear DSL) The real-ear SPL screen permits the user to view all the major components of the hearing loss and the hearing aid fitting on one SPL screen with real ear measurements. The hearing thresholds and uncomfortable loudness levels, which are generally measured in HL, are converted to SPL. Target insertion gains are also converted to dB SPL. Provision is made to show three aided responses, in SPL, at three different source amplitude levels.
5.4.2 Understanding the specifics of DSL The Desired Sensation Level (DSL) method is a hearing aid selection and fitting approach with the goal of making amplified speech audible. The desired sensation levels for amplified speech are determined at each frequency for all degrees of sensorineural hearing loss. The DSL method is not an insertion gain formula approach (i.e. NAL, POGO), but it does use probe microphone instrumentation as well as 2-cc coupler measurements in the test box.
5.4.3 Viewing the SPL screen See Figure 5.4.3 for a picture of the SPL testing screen. 1. Curve box containing the source type and amplitude of each of the three measurement curves. 2. Source type for current curve 3. Noise reduction status for current curve 4. Reference microphone status 5. Smoothing status 6. Leveling status 7. RMS source level used to take measurement 8. RMS of the current curve. Not available with pure-tone source types. 9. Output limit status 10. Selected ear 11.
2. Set up the client, insert the probe tube, and level the sound field speaker as described in Section 5.1. 3. Insert the client’s hearing aid into the ear, making sure not to dislodge the probe tube. 4. Select the desired source type with F7. See Section 2.4 for a discussion of source types. 5. Select the desired amplitude for the first aided measurement by using the AMPLITUDE knob. We recommend a soft speech level such as 50 dB SPL. 6. Press START/STOP to start the measurement.
Figure 5.4.4—SPL screen displayed on an external monitor 5.5 Audibility Index (AI) The Audibility Index screen displays the audiogram, target, and aided response in dB HL on one display. Technically speaking, these aided responses should be called “aided audiograms” because they incorporate the insertion gain obtained by making unaided and aided measurements. This insertion gain is then added to the unaided audiogram to obtain the curves shown on the HL display.
5.5.1 Viewing the AI display See Figure 5.5.1 for a picture of the Audibility Index display. 1. dB HL graph for unaided and aided audiogram responses 2. Aided audiogram responses (from insertion gain measurements) 3. Insertion gain target displayed in dB HL 4. Table containing expected percentage of audibility of speech 5. Selected fitting rule 6. Source type for current curve 7. Noise reduction status for current curve Figure 5.5.1—External video display of the Audibility Index 8.
13. Output limit status 14. Selected ear 15. Graph containing unaided and aided gain response 5.5.2 Performing AI measurements Performing AI measurements is just like performing normal insertion gain measurements. Follow the instructions in Section 5.3.2 and 5.3.3. Instead of choosing IG in step 2 of Section 5.3.2, use F2 to choose the AI display. Alternately, perform the insertion gain measurements as normal in the Insertion Gain display, and then press F2 to switch to the AI display.
5.6.1.1 To perform the coupler measurement The coupler measurement part of the RECD is saved into the analyzer’s permanent memory until another measurement is stored on top of it. This saves a lot of time because it means you only have to perform the real-ear part of the RECD for each client instead of performing both the coupler and the real-ear measurements. Note: Steps 1-7 are optional but good to do in order to get the most accurate RECD. 1.
8. Plug a 50-ohm insert earphone into the external speaker jack on the back of the FP40. An adapter may be needed if you are taking the insert earphone from an audiometer. 9. Insert the larger coupler microphone into HA-2 coupler. 10. Attach insert earphone plastic tip to the tubing of the HA-2 coupler. See Figure 5.6.1.1B. 11. Press F5 to enter PROBE mode. 12. Press F1 to enter MENU. 13. Press F4 to enter CAL MIC(S). 14. Press F7 to select HA2 ER3A. 15. Press [START/STOP] to begin measurement.
Foam eartip Foam eartip Probe mic Lapel clip 3A IN EARSERT PHO NE 3A RT INSE NE PHO EA R Probe mic WITH FOAM EARTIP External speaker jack 3A IN EARSERT PHO NE Custom earmold Microphone jack Probe mic on earhook WITH CUSTOM EARMOLD Figure 5.6.1.
Figure 5.6.1.2B—Measured RECD 5.6.2 Performing coupler measurements to a DSL target 1. Enter your client’s thresholds and generate a target as described in Section 5.2. Make sure to input your client’s age before generating the target. 2. Enter the Target 2-cc screen by pressing F7. 3. Decide whether you want to use the average RECD data to create the 2-cc target or the client’s measured RECD. To measure the client’s RECD, follow the instructions found in Section 5.6.1.
Figure 5.6.2A—Coupler gain measurement with a DSL target 11. Press F5 to enter SSPL MODE. You should see a series of star symbols on the screen. These symbols stand for the highest comfortable levels predicted for this patient. Again, make sure the RESER is set to zero. 12. Press [START/STOP] to take a pure-tone 90 dB measurement. If the resulting measurement is higher than the target symbols, those sounds will be uncomfortable for the patient.
If the FP40 has the OES Option, it is also possible to make a prescription that uses the modified Zwislocki (MZ) couplers. 5.7.1 Viewing the Target 2-cc screen Figure 5.7.1 contains a picture of the Target 2-cc screen. 1. Gain graph containing the 2-cc target including the calculated target and modified target if available. 2. Selected ear. 3. Selected aid type. 4. Selected coupler. 5. Status of unaided response used to make the 2-cc conversion. 6. Fitting rule. 7. Signal source type. 8.
5.7.2 Taking the FOG measurement 1. Follow the instructions found in Section 5.2 to generate a real-ear target. 2. Press F7 to enter the Target 2-cc screen. 3. Use F2 to select whether or not you want to use the KEMAR average unaided response to generate the 2-cc target, or the client’s measured unaided response. To measure the client’s unaided response, follow the instructions found in Section 5.3.2. 4.
7. Age of client. 8. Instructions for performing the SSPL 90 measurement. Note: Once a measurement has been taken, the modification table will disappear from the display. Figure 5.7.3—The SSPL 90 screen 5.7.4 Taking the SSPL 90 measurement This measurement is always made with a pure-tone sweep in order to make sure the fitting is comfortable for the client even when presented with 90 dB SPL of sound at any frequency. 1. Press F5 to enter the SSPL 90 screen. See Figure 5.7.3 for a picture of this screen.
5.7.5 Checking an aid against a prescription This procedure allows the operator to reenter data from the client’s initial prescription FOG curve, so that the actual “custom” hearing aid ordered can be compared and adjusted to the original FOG Curve when it is received and before the client is scheduled for a real ear fitting. It is assumed that you have followed the instructions found in Section 5.7.2 and 5.7.
5.7.6 Accounting for venting effects You can make 2-cc targets more accurate by modifying the target to account for venting effects. Target Coupler FOG Vent Corrections Frequency (Hz) 250 500 750 1k 1.5k Tight Seal — — — — — Slit Leak 2 2 1 — — 1 mm 1* 2* 1 — — 2mm 7* 1* — — — Long Open 17* 10* 4* 1* — Short Open 26* 21* 14* 10* 5* Note: Use starred values only if prescribed insertion gain is greater than 0 dB at that frequency. Otherwise, use no correction.
5.8 Miscellaneous This section describes a few real-ear features accessible from the Setup Menu. 5.8.1 Single frequency response In some cases, it’s useful to be able to evaluate the real-ear response to a tone presented at a particular frequency. The single tone measurement in the Probe screens is always warbled. To do this: 1. Enter the Probe mode by pressing F5 from the coupler screen. 2. Set up the client for testing as described in Section 5.1. Make sure to level the sound field speaker. 3.
5.8.3 Reset Level The reset level is the sound pressure level that the analyzer automatically returns to when the RESET button is pressed. By default, it is set to 70 dB SPL. This is set in the Setup Menu under PROBE SETTINGS. 5.8.4 Data Display It is often useful to look at the numerical data from real-ear measurements. The DATA/GRAPH button is used for this purpose. To select which curve is converted to numerical data: 1. Press F1 to enter the Setup Menu from any of the real-ear measurement screens. 2.
5.9 Body, CROS, and BI-CROS aids When using the FP40 probe with a Body aid, CROS, or BI-CROS aid, we suggest the following setups and procedures. But you certainly may experiment with different methods. 5.9.1 Testing body aids The setup below is recommended for Body aids. Follow normal Insertion Gain measurement procedures. REFERENCE MIC REFERENCE MIC 12" PROBE MIC SPEAKER (HEAD HIGH) TOP VIEW 12" SIDE VIEW PROBE MIC (ON EARHOOK) SPEAKER BODY AID (FACING FORWARD) Figure 5.9.
5.9.2 Testing CROS and BICROS aids Four Goals: 5.9.2.1 5.9.2.2 5.9.2.3 5.9.2.4 Measure Measure Measure Measure the head baffle effect how well the aid overcomes the head baffle effect the overall insertion gain the insertion loss to the “good” ear Each of these measurements uses the insertion gain measurement technique, taking advantage of the fact that insertion gain is a difference curve between two measured curves (usually the unaided and aided response).
5.9.2.2 How Well the Aid Overcomes the Head-Baffle Effect CROS A. Unaided—Measurement of “good” ear canal (baffled by head) Set up the FP40 analyzer as follows. • Reference microphone ON • Sound field LEVELED • Unaided CUSTOM GOOD EAR BAD EAR 12" • Reference microphone over pinna of bad ear • Probe microphone inside unoccluded ear canal of good ear SPEAKER • Loudspeaker at 90º, 12 inches from bad ear B.
The difference curve, labeled “Insertion Gain” on the screen, shows the benefit of adding the second microphone for sound arriving from the “bad” side. 5.9.2.3 Overall Insertion Gain Note: Since it has not been shown for CROS and BI-CROS instruments that a 45º position of the loudspeaker improves the reliability of insertion gain measurements, we recommend a 45º position of the loudspeaker only for monaural instruments, and a 0º position for CROS and BI-CROS instruments. CROS A.
B. Aided—Measurement of “better” ear Same setup as A, except… • Complete aid in place in better ear and set at use gain • Both transmitters on The difference curve, labeled “Insertion Gain” on the screen, shows the overall benefit of inserting the hearing aid. 5.9.2.
5.10 FM Systems For users who test FM Systems, a comprehensive guidebook is available free of charge. Contact the factory and request the publication Testing FM Systems with FONIX FP40 Analyzers 5.11 Testing Directional Aids Perhaps the most convenient way to test directionality is with a real-ear measurement. You can use the Insertion Gain screen on the FP40 analyzer to show you the forward and reverse responses as well as a curve showing the directional advantage.
9. Press START/STOP to start the measurement. While the measurement is running, you may want to adjust the angle of the speaker (or the position of the client) to make sure the sound source is hitting the null position of the aid. You are looking for the response with the least amount of amplification. 10. Press START/STOP to stop the measurement once it has stabilized. The “unaided” response is now the reverse measurement of the directional aid. Figure 5.11.
Chapter 6: Spectrum Analysis 6.1 Spectrum Mode This mode is only available on FP40 instruments that have the Real-Time/Composite Signal. The FONIX FP40 can be used as a sound spectrum analyzer in either the coupler (test box) or realear test modes. When the Spectrum Mode is selected, external sounds can be measured through the microphones, or through a direct electrical connection, and displayed in an amplitude-vs-frequency format. 6.2 Entering the Spectrum Mode The FP40 must be in the “COMPOSITE MODE.
6. Use F3 to select AIDED 1. 7. Place the hearing aid in the ear. The aid should be turned off. 8. Push the START/STOP button. Instruct the client to sustain the vowel sound “ee.” 9. While the “ee” is still sounding, and once the curve on the screen has stabilized, press START/STOP. Note the total RMS Output in the ear canal as indicated in the status box. 10. If the SPL seems high, you might modify the vent size. Use F3 to select AIDED 2 and repeat steps 6 and 7.
APPLICATION 3: REAL EAR AIDED RESPONSE (REAR) IN SPL USING AN EXTERNAL SOUND SOURCE. This application is similar to the Insertion Gain test described in Application 2. But instead of measuring real-ear gain you will measure the SPL generated in the ear canal and compare it to the patient’s HTL and UCL values. This is sometimes known as a “Visible Speech.” Suggested Procedure: 1. Prepare the sound source. 2. Press F5 from the Main Coupler screen to enter the Probe Mode. 3.
Chapter 7: Telecoil Testing Telecoil testing is available on serial number 940000 and above, manufactured in September, 1994 and later. Testing with the Telewand is available with software version 3.60 and above. 7.1 Setup with the Telecoil Board 1. Set up the hearing aid in the usual way, by connecting it to the correct coupler and insert the test microphone. You may use either a normal hearing aid battery or a battery substitution pill to power the aid. 2.
7. Press F1 to return to the Main Coupler screen. 8. Press F2 to turn ON the telecoil feature. 9. Orient the hearing aid on the telecoil board for the maximum output. (If you’re using the Composite signal, you will have to press START/STOP to start the test signal.) Figure 7.1B shows various positions that could be tried. Notice that the hearing aid must be at the center of the board. Figure 7.1B Orienting hearing aid for maximum output 7.2 Setup with the Telewand 1.
4. Use the AMPLITUDE and FREQUENCY knobs to select MAIN F2 under FUNCTION KEY DEFIN. 5. Press START/STOP repeatedly to select TELECOIL. 6. Press F1 to return to the Main Coupler screen. 7. Press F2 to turn ON the telecoil feature. 8. Hold the Telewand next to the hearing aid as if you were holding a telephone next to the aid in the patient’s ear. That is, if the aid is a BTE, hold the Telewand parallel to the aid’s body. See Figure 7.2. If the aid is an ITE, hold the Telewand against the aid’s faceplate.
7.4 Testing 1. Use the amplitude knob to increase the level of the magnetic field. If you are using the Composite signal, the amplitude will be displayed in the Status box. If you are using a puretone signal, the amplitude is displayed in the lower right corner of the screen. When changing the field strength from 00 mA/M to 10 mA/M, the amplitude of the response should increase by 10 dB if you are in an environment where it is possible to make valid telecoil measurements.
Appendix A: Specifications SINE SIGNAL Frequencies 1/12 octave frequencies from 200 to 8000 Hz, closest 100 Hz, Normal Sweep within 1 %: 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1, 2.2, 2.4, 2.5, 2.6, 2.8, 3.0, 3.1, 3.3, 3.5, 3.7, 4.0, 4.2, 4.5, 4.7, 5.0, 5.3, 5.6, 6.0, 6.3, 6.7, 7.1, 7.5, 8.0 kHz. Frequencies Fast Sweep 0.2, 0.3, 0.4, 0.5, 0.6, 0.8, 1.0, 1.2, 1.6, 2.0, 2.5, 3.1, 4.0, 5.0, 6.3, 8.0 kHz.
Tolerance +/- 0.01V, no load. Battery Type Selection Under software control from front panel, but proper size battery pill must be selected. DIGITAL READOUT OF SPL Frequency Range 200 Hz through 8000 Hz. Amplitude Range 0 dB SPL through 149.9 dB SPL, -70 dB through +100 dB gain. Max Input Signal 150 dB SPL. Resolution 0.1 dB. Type Accuracy True RMS if Source is set to “off ”. From 250 Hz to 2500 Hz, 2 dB +/- one digit. All other frequencies, 3 dB +/- one digit.
Auto Shutdown General shutdown after no operation of controls for 15 minutes (battery operation only). Battery Charger Built-in automatic battery charger. Full charge in 10 hours. DISPLAY SCREEN Backlit Liquid Crystal Display Graphical display, 640 pixels wide x 200 pixels high. Color Blue background with white lettering or white background with blue lettering. Illumination Fluorescent edge lighted. Display Angle Module tilts from 12 to 90 degrees with respect to horizontal.
PHYSICAL DESCRIPTION Dimensions 20.125” x 14.750” x 6.5” (50,5 x 36,9 x 16,25 cm) (with lid on case). Color Light grey with black trim, white control panel. Weight FP40: 25 pounds (11,40 kg) with lid and battery; 22 pounds (10 kg) without battery FP40-D: 16.5 pounds without accessories SAFETY Safety Approval Note that for the UL listing to be valid, all mains connected electrical equipment attached to the FP40/FP40-D must conform to UL 544.
Appendix B: Calibration Calibration Your new instrument has been calibrated at the factory. However, from time to time, you will wish to check it with an external source, a sound level calibrator. Frye Electronics offers the QUEST QC-10 calibrator, especially adapted to our equipment, but other models can also be used. While in the SETUP menu, push F4, CAL MIC(s). Calibrating the Coupler /Reference Microphone 1. Place the 1” to 14 mm adapter in the QC-10 calibrator. 2.
Calibrating the Probe Microphone 1. Place the probe calibration adapter in the 1” to 14 mm adapter as show in Figure B-3 2. Put the probe tube in the adapter, pushing it completely through, as shown in Figure B-4 Proceed as in Fig. B-1, except observe the measured output for the probe microphone and adjust the calibration at the control marked PROBE GAIN. Figure B-3 Figure B-4 Compensating Probe Microphone to Reference Microphone.
7. PUSH F6 COMPEN (compensate) Probe. When the signal stops, the probe has been compensated and the compensation has been saved. 8. To view the effects of compensation, EXIT MENU, adjust AMPLITUDE to 70 dB and push START. Note: You may want to view the uncompensated differences between the two microphones. Follow instructions 1-7 above. Interrupt the compensation process by pushing RESET shortly after you hear the tones. Then follow instruction 8 above to view uncompensated differences.
Appendix C: History of Changes VERSION 1.0 (ORIGINAL RELEASE 3/90) VERSION 1.2 (5/90) Added: JIS Standard. VERSION 1.3 (8/90) Added: ISI Standard; CRT Option. VERSION 2.0 (3/91) Added: Fast Sweep VERSION 2.1 (2/92) Added: New Multi-Curve in Real Ear & Coupler. Target 2cc FOG & SSPL90. Easy-to-read Double-Size Characters. Full & Partial Menu Choices. Probe Signal Selection (F7 Definition). VERSION 2.3 (4/93) Added: 40 dB Input Source (K-Amp). Spectrum Analysis Mode.
Appendix D: Custom RECD Test There are two methods of getting Custom RECD measurements with the FP40 using the Probe Option. One method uses a linear BTE hearing aid and the other uses an ER-3A Insert Earphone. This appendix describes the BTE method. The insert earphone method is described in Section 5.6.1. BTE / RECD Method This simple method doesn’t require any additional equipment. A linear BTE hearing aid with a moderate amount of gain is all that is required.
Part C: The RECD Calculation. On a separate sheet of paper, subtract the REAR measurements (Part B) from the 2cc coupler measurements (Part A). The differences at the required test frequencies are the RECD values. These RECD correction factors can be used for DSL and TARGET 2cc (sections 7.7.1, 7.7.3) calculations.
Appendix E: The FONIX CIC Option 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.
of the cavity between the hearing aid and the TM by moving the aid closer to it, we should expect to see the TM play a more important part in determining the response of the aid. For more shallow standard earmolds, the volume of the central cavity of the ear reduces the effect of the TM’s frequency impedance changes. This is because the volume of the cavity is added to the equivalent volume of the TM.
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 1.4 3100 4.07 5100 4.95 7100 -5.
Appendix F: Storage Compartments in the FP40 pull up here Accessories are stored in three compartments located inside the FP40’s carrying case lid. To open a compartment, pull upward at the top recessed area. The lid, which is held in place with velcro, will come completely off. To replace the lid, align its bottom edge with the bottom edge of the compartment, interlocking them as shown here. Press the top of the lid down to secure it in place.
Appendix G: 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: 1. 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. 2. CRT/VGA/LCD display monitor is not working a. b. c. d.
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. There may be a coupler vent leak. c. The #13 coupler tubing could be cracked or broken. PROBE PROBLEMS: 1. Probe Reference Mic does not Level. a. b. c. d. e. f. Check the reference mic calibration. Be sure the reference mic is properly plugged into the instrument.
Appendix H: Probe SPL Mode Description The Target IG is converted to the Target SPL in the following steps. 1. Add the source level for Aided curve 2. 2. Interpolate from 10 frequency to 80 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. If Aided 2 is Speech Weighted, subtract the Speech Weighting in Table 2.
TABLE 1 Average Real-Ear Unaided Response (REUR) FREQ GAIN (Hz) 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 FREQ GAIN (Hz) dB 2100 13.9 2200 14.7 2300 15.1 2400 15.0 2500 15.1 2600 15.0 2700 14.6 2800 14.1 2900 13.6 3000 13.7 3100 13.8 3200 14.1 3300 14.5 3400 14.8 3500 14.9 3600 14.7 3700 14.3 3800 13.9 3900 13.5 4000 13.1 FREQ GAIN (Hz) dB 4100 12.7 4200 12.4 4300 12.2 4400 12.
TABLE 3 HL to real-ear SPL conversion table from ANSI S3.6-1989 Table G.1 FREQ (Hz) 250 500 750 1000 1500 2000 3000 4000 6000 8000 dB This table is only used when the age is not specified in the Target Screen. For age-specific conversion values, contact Frye support at support@frye.com or call the factory. 19.0 12.0 10.5 9.0 12.0 15.0 15.5 13.0 13.0 14.
FONIX FP40 Portable Hearing Aid Analyzer
Appendix I: DSL Programming Notes Notes on the DSL® Programming The DSL® (Desired Sensation Level) software in the FONIX FP40/FP40-D program is based on the latest copyrighted I/O computer program. The DSL method was originally described by Seewald, Ross & Stelmachowicz in 1987. Its purpose was to provide amplified speech that is consistently audible, comfortable, and undistorted across the broadest relevant frequency range.
channel instrument can meet those targets. If the compression ratio targets are very different in different frequency regions, a dual-channel or multi-channel instrument may provide a better fitting for the client. When setting the aid, the compression ratio should be set to match the average of the target compression ratios in each frequency band. Warning: If the prescribed compression ratio is greater than 4:1, a WDRC fitting may not be appropriate for this hearing loss.
Appendix J: Battery Simulator Impedances FP40 Battery Simulator Settings Battery Size Battery Chemistry Impedance NONE 0V 1 OHMS 10A/230 ZINC-AIR 10 1.3V 312 SILVER 10 1.5V 312 MERCURY 8 1.3V 312 ZINC-AIR 6 1.3V 13 SILVER 8 1.5V 13 MERCURY 8 1.3V 13 ZINC-AIR 6 1.3V 76 SILVER 5 1.5V 675 MERCURY 5 1.3V 675 ZINC-AIR 3.5 1.3V 401 MERCURY 1 1.3V 1 1.5V 10 1.0V 10 1.3V AA LOW BAT 1.0V 5 ZINC-AIR FONIX FP40 Portable Hearing Aid Analyzer Voltage 0.
Index A Accessories 6 Optional 6 Real-Ear 8 Standard 5 ACIC 55, 72 Aided response 87 ANSI 23, 43, 48 ANSI S3.22-1987 55, 56, 58, 59, 60, 61, 63, 64, 66, 67, 69, 70, 71 results 64 settings 63 ANSI S3.22-1996 55, 59 results 58, 62 ANSI S3.22-2003 55 ANSI S3.
H Harmonic distortion 45 Hearing aid setup 39 body aid 41 eyeglass aid 41 ITE/ITC/CIC 39 History of changes 133 I ICRA 23, 43, 48 ID Option 3 IEC 55, 67 results 69 settings 68 Insertion gain 88 Intermodulation distortion 2 ISI 55 J JIS 55 K Knobs, front panel 12 L Label 31 Lamps, front panel 11 LCD screen 10 Leveling 36, 37 sound field 79 Line power 11 M M200 Microphone 8 Magnetic fields 123 Main Coupler Screen 35, 39, 42, 44, 45, 47, 48, 52, 53 microphone adapter 5 Monitor headset 9 Mounting sle
Shutdown 16 Single frequency response 44, 107 Smoothing 107 Sound chamber 7 Sound level calibrator 6 Source type 21, 42 Speaker, swing arm 9 Specifications 125 Spectrum Mode 117 SPL measurements 90, 92 SPL Mode 145 SPL Screen 92 SSPL 90 Screen 103 Storage compartments 141 T Target 2-cc 102 FOG 103 Target Screen 80 Telecoil, external 7, 121 Telecoil Option 1 Telewand 8, 122 Three frequency average 45 Troubleshooting 143 U Unaided response 86 V VGA 3, 12 VGA Option 1 W Warranty 16 Index 155
