Evaluation of five different cochlear implant designs: audiologic assessment and predictors of performance.

The audiologic performance of 54 postlingually deafened adults wearing cochlear implants was uniformly evaluated. The participants had 9 months' or more experience with one of five different cochlear prostheses (Los Angeles Single Channel (N = 11), Vienna Single Channel (N = 4), Melbourne Multichannel (N = 18), Utah Multichannel (N = 19), San Francisco Multichannel (N = 2). The multichannel designs enabled participants to recognize more environmental sounds, provided more speech reading enhancement, and enabled most users to understand limited speech in the sound-only condition, compared to the single-channel implant group.

Preliminary assessment of the Los Angeles, Vienna and Melbourne cochlear implants.

We tested four patients using the single-channel cochlear implant from Los Angeles, three patients using the single-channel cochlear implant from Vienna, and two patients using the multichannel cochlear implant from Melbourne. Tests from the MAC battery and the Iowa Cochlear Implant Battery were used. Most patients were able to identify some environmental sounds. Three of the patients had difficulty distinguishing between male and female voices, and three could not distinguish between a noise and a voice. All patients had difficulty discriminating between unknown speakers of the same sex. A four-choice spondee test in noise showed that all patients suffered drastically from background noise. In all cases there was an improvement in lipreading ability with the implant. On a sentence test with a contextual cue seven patients got some words with sound alone. Results obtained with the multichannel implant are superior on several tasks, but we have tested too few patients to allow us any firm conclusions.