HEARING AID TEST BOX

Typical Number in Hospital: 1

Cost Bands: 4,5

References:

Audiology departments need to test the performance of hearing aids to ensure their correct operation and assess the effect of their preset controls. The hearing aid test box comprises a small acoustically treated chamber (which may be bench-top size or free standing), an audio oscillator, amplifier, loudspeaker (within the chamber), 2 cc coupler, microphone and sound level metering circuitry. The hearing aid is placed within the calibrated sound field within the chamber, and its output is monitored with the 2 cc coupler, microphone and metering system. Measurements can be taken at several discrete frequencies or by sweeping the test frequency continuously throughout the required range (typically 250 Hz to 5 kHz). The usual tests include measurement of the gain of the hearing aid, maximum output and frequency response, although distortion measurements are sometimes included.