Binaural Integration by Cochlear-Implant Users During Voice Matching Tasks

Abstract

The capacity for bilateral cochlear-implant users, bimodal cochlear-implant users, and normal-hearing control subjects to match auditory information presented independently to both ears was examined. Spondee words were re-synthesized to produce three sets of voice stimuli where pitch and spectrum were manipulated independently or together. Children (ages 5-18) were asked to turn a knob to make the voice presented to one ear match a model voice presented simultaneously to the opposite ear. The children were also asked to match voices presented sequentially, either to the same ear or to opposite ears. Statistical comparison of the bilateral cochlear-implant and normal-hearing groups showed that cochlear-implant users had lower sensitivity to the acoustic properties of speech tested, but that their ability to match and integrate them binaurally followed a normal-like pattern. Hearing in noise was tested for conditions where the voice presented to each ear was the same (diotic) or different (dichotic).