IntriCon Corporation
Feedback reduction for high frequencies

Abstract:

A digital signal processor processes acoustic sound in a body-worn hearing assist device including separating the microphone signal into frequency bands. Two of the frequency bands, which are preferably adjacent, are considered as a pair. In one of the frequency bands in the pair, the band signal is replicated/split into two subsignals. One of the subsignals is frequency shifted into the other frequency band of the pair. The input signal from the paired frequency band is either significantly attenuated or altogether discarded. The unshifted subsignal is attenuated relative to the frequency-shifted subsignal, which is preferably amplified, before both subsignals are combined as part of the acoustic output. Considering both frequency bands as a pair, the likelihood of feedback is significantly reduced or eliminated.