الفهرس 
? Speech Processing Strategies in Cochlear ImplantOnly 14 pages are availabe for public view
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Abstract
C
ochlear implant technology continues to afford increasingly higher levels of speech Understanding. Cochlear implant recipients, however, continue to exhibit considerable difficulty understanding speech in background noise. Possible means to improve the ability to understand speech in noise include utilization of multi-microphone technology and coupling the sound processor to a frequency modulation system. but the incorporation of a noise reduction algorithm as a preprocessor to the cochlear implant speech processor may be a more convenient and cost saving strategy.
ClearVoice is a recent proprietary algorithm from Advanced Bionics, based on the HiResolution sound processing strategy, and has been designed to improve speech understanding in difficult listening environments by reducing the stationary noise and emphasizing the dynamic channels containing more speech. The algorithm acts on the signal after it has been passed the band filters, and is based on the assumption that the speech envelope is modulated and the noise envelope is unmodulated. from the analyses of the modulation frequency and modulation depth, the signal-to-noise ratio is estimated in each frequency band separately and bands with low modulation depths and thus low SNRs are attenuated.
The aim of this work was to measure the potential additional improvement, if any, in speech recognition in noise using ClearVoice speech enhancement algorithm in children using HiResolution sound processing strategy.
The study group consisted of twenty children; 12 males (60%) & 8 females (40%); ranging in age from 5 to 10 years. They were implanted with Advanced Bionics (AB) cochlear implants and using HiResolution sound processing strategy.
The protocol of the study included: Programming of CI with activation of ClearVoice speech enhancement algorithm in two modalities (medium & high) and let the patient to use each program for 1 month, Full history taking, Aided pure tone assessment, Speech perception test in quiet & in noise to the basic program and ClearVoice program in two modalities (medium &high), MMN test to the three progams and IT- MAIS questionnaire.
The resulting data showed significant improvement in speech discrimination in noise when using ClearVoice compared to the basic program especially ClearVoice high modality with no impairment of discrimination score in quiet condition. MMN results showed no significant differences regarding the three programs. IT-MAIS questionnaire gives best score in ClearVoice high condition.
This study recommended that all cochlear implantees of Advanced Bionics to use ClearVoice speech enhancement algorithm to improve speech intelligibility in noisy conditions.