User Guide

PAMS Technical Documentation 3 - Audio System
NPE-4
Original ãNokia Corporation. Page 3-21
HDC-9P is a purely passive audio accessory.
HDW-1
Bluetooth headset developed in the Tomahawk project.
The BT headset is containing a microphone, a earpiece, bluetooth module and its own
audio codec. HDW-1 is battery supplied
Audio connection is full duplex digital transmission with error correction.
Loopsets:
LPS-1
The Loopset is a hearing aid accessory for hearing impaired persons to use mobile
phones.
It consists of a Wire-loop and a microphone placed in a collar around the person's neck.
This is detected in the mobile as a Headset. In the UI SW it is possible to change profile
Table 10:
HDC-9P interface specifications
Object Specification Notes
Receiver input impedance 150 Ohm +/- 25 % @ 390 mV at 1 kHz
Maximum Sound pressure level 106 dB SPL at 1 mW
Transmitter output impedance 2200 Ohm +/- 30 % at 1 kHz
Transmitter sensitivity - 43.5 dBV/Pa +/- 3 dB at 1 kHz
XMIC bias voltage 1.5 V Typical
XMIC bias current 1.5 mA Maximum
Table 11: Selected specifications for HDW-1 BT Headset
Min Typ Max Unit
Ear signal in Codec after PCM
DAC converter
80 490 mVrms in codec
Ear signal amplifier gain in codec -18 2 12 dB / setting by 2 dB steps
Electroacoustic transfer function
(Rx)
17 dBPa/V/0.5m
Microphone signal level 3 4 6 mV/Pa
Level at AD input in Codec 58 490 mVrms in codec
Mic. amplifier gain in codec 20 42.5 dB
Noise voltage, microphone 5 uVrms