On the rehabilitation of cochlear implant patients using a flexible and versatile speech processing technique with a spectral approach

A flexible and versatile speech processing technique for rehabilitating deafness by using a cochlear implant system is described. The proposed technique permits not only speech signal processing for delivering appropriate stimuli, but also takes advantage of a visual tool dedicated to adjust as well as to control stimulation. Its digital approach allows adaptability to any cochlear-implant apparatus driven by a digital signal processor (DSP). The sound spectrum can be divided into different frequency bands that can be assigned to stimulation channels located in the inner stimulator. These bands are completely programmable and are adjusted according to a patient´s hearing pathology and comfort. The generation of stimuli in the nerve endings of the cochlea can be described as follows: The proposed technique permits the extraction of the speech signal energy contained in the assigned frequency bands. Then, it codes the output information and transmits the appropriate commands to the internal part via the prosthesis´ modulator. A compatible personal computer is connected to the external part of the prosthesis to allow clinical assessments as well as adjustments of the different apparatus parameters. This technique was conceived to generate a real time display showing the affected frequency bands as well as their relative stimulation levels. This assists patients during their re-education phase by giving a visual reference. Software provided in this stimulation technique ensures flexibility in programming, ease of use as well as different safety features that could help in adapting to an individual´s needs