The engineering of future cochlear implants

Publisher’s permission requested and denied.Speech is a complex acoustic signal, and information is transmitted to the brain at a rapid rate. For example during a conversation ten phonemes are uttered per second. Furthermore, these complex speech sounds are coded into patterns of neural discharges that enable the subject to understand speech. In order, therefore, to bring speech signals directly to residual auditory nerve fibres, considerable processing of the speech signal is required before the central nervous system will recognise and comprehend it. The magnitude of the task can be further appreciated when one considers that there are an average of 31,400 nerve fibres in the human auditory nerve and a large proportion of these convey information to the brain about the speech frequencies. Research studies are showing, however, that the perception of ongoing speech with cochlear implants may be achieved 'With speech processing strategies which can be achieved by current electronic technology