Binaural hearing and future hearing-aids technology

Abstract
Normal-hearing persons can make use of two ears in daily listening, and this binaural hearing offers a lot of advantages compared to monaural hearing. The mechanisms of binaural hearing are based on an analysis of interaural differences and monaural cues that are due to directional dependent filtering of the outer ears as described by Head- Transfer Functions. In order to support the binaural abilities of hearing-impaired persons it is necessary to provide them with interaural and monaural cues that are in the range of their "natural" values. This can only be guaranteed if a new generation of hearing aids is introduced, namely binaural hearing aids, which consist of two hearing aids that are controlled by a central processor. This processor may have tasks ranging from an adjustment of the amplifications of both hearing aids up to a simulation of binaural processing which will support the understanding of speech in noise. A Cocktail-Party-Processor which may be used for this purpose and results of intelligibility tests are presented.