Design of a hearing test probe using active acoustic noise attenuation Academic Article uri icon


  • Most hearing tests today are done in soundproof rooms. A method is proposed for conducting tests in a regular room while using a hearing test probe with active acoustic noise attenuation. The system consists of passive and active attenuation parts. The passive attenuation is achieved by a foam plug placed in the ear canal. The active attenuation is achieved by using two mini‐microphones, a receiver and a DSP board. The first microphone is placed at the ear canal entrance and receives the acoustic noise. It then transfers the noise to the DSP board (with the TMS320, placed in a PC), which by using an adaptive algorithm transmits the antinoise signal to the receiver placed in the ear canal. The second microphone is placed near the receiver and produces the error signal to the adaptive process. The system was analyzed on a larger scale acoustic model and a 20‐ to 40‐dB noise attenuation was achieved for tones up to 4 kHz (not including the plug passive attenuation). Theoretical analysis of the acoustic filte...

publication date

  • January 1, 1993