The Optimization of Binaural Hearing with Hearing Aids Jeremy Agnew This presentation will focus on Starkey's new Cetera digital hearing aid. Conventional analog amplification can restore the audibility of lost sounds and is usually successful in quiet listening situations. However, simple amplification does not always restore the ability to understand speech in difficult listening situations. Part of this problem is due to the alteration of binaural phase and amplitude cues by analog hearing aids. These cues are required for the normal hearing mechanism to produce binaural squelch effects, thus allowing the brain to suppress interfering sounds that the listener does not wish to hear. The fitting of Cetera hearing aids includes measurement of the difference between unaided and aided external auditory canal filtering effects for the individual being fitted, then compensation with the Cetera digital filtering algorithm for the effects of the hearing aid inserted in the ear. The Cetera algorithm restores the natural relationships of phase and amplitude of the sound processed through the hearing aids during amplification. In this way the relationship of binaural cues that the central auditory system expects to hear is maintained, thus allowing the user's residual binaural hearing to hear and interpret these cues in the correct relationships. |