Effect of acoustic dynamic range on phoneme recognition in quiet and noise by cochlear implant users

The present study measured phoneme recognition in cochlear implant users when the dynamic range of the input speech signals was reduced by either peak clipping or center clipping. In quiet, reducing the acoustic dynamic range to 30 dB still provides sufficient speech information for phoneme identification in cochlear implant users with 4-channel continuous interleaved sampler strategy and normal-hearing listeners listening to correspondingly degraded speech. Phoneme recognition decreased when the dynamic range was reduced below 30 dB: peak clipping was more detrimental to vowel recognition and center clipping was more detrimental to consonant recognition. However, in background noise, center clipping produced a small increase in speech recognition for cochlear implant listeners. (C) 1999 Acoustical Society of America.