Speech-evoked auditory potentials in cochlear implant listeners.

摘要

The purpose of this study was to examine the effect of cochlear implant (CI) channel number on the neural representation of acoustic changes contained in speech. Eleven normal hearing monolingual English speaking adults were tested. Unprocessed naturally spoken syllables, containing medial vowels, as well as processed versions (simulating 2, 4, 8, 12, and 16 implant channels) were used for behavioral and electrophysiological testing. Behavioral results. Similar to our previously published findings, perception improved as a function of channel number (Friesen et al. 2001); however, the effect of channel number was not the same for all stimulus tokens. The perception of 'heed' far example was remarkably better than the perception of 'hid' with only 2 channels of information. Physiological results. Neural response patterns differed as a function of channel number. Evoked neural activity, in response to the acoustic changes contained in the speech signal, increased in amplitude and decreased in latency as the number of channels increased.