Evaluation of a non-linear spectral subtraction noise suppression scheme in cochlear implant users

Abstract

The aim of the study was to determine benefit to speech recognition in noise by adult cochlear implant users with the non-linear spectral subtraction (NSS) noise suppression strategy. Users of the Nucleus 22 or Nucleus 24 cochlear implant systems were tested with sentence materials combined with stationary noise at +5 and +10 dB signal to noise ratio (SNR), with and without NSS processing applied offline. Sentence scores were significantly higher with NSS processing, for both SNRs. The effect was greater at +5 dB SNR (12% improvement with NSS) than at +10 dB SNR (5% improvement with NSS). These results are promising and suggest that online implementation of NSS as part of cochlear implant processors has the potential to yield benefits for speech recognition in noise. Copyright © 2006 John Wiley & Sons, Ltd.