Performance of 3M/house cochlear implant users on tests of speech perception

This report documents both closed- and open-set speech recognition performance for 18 adult experienced users of the 3M/House single-channel cochlear implant. The stimuli included tape-recorded, standard word and sentence recognition tests, an environmental-sound test, nonsense syllables, and sentences presented in auditory (implant-only), visual, and auditory-visual modes. All subjects were tested individually in a single session using their own cochlear implants, set to typical comfort use settings for running speech. Subjects' oral responses to the stimuli were transcribed by the experimenters and scored for percent correct. The results revealed considerable individual differences among the subjects and their performance on different tests. All subjects scored better than chance on the closed-set tests. Although they performed considerably poorer on the open-set tests, approximately half of these subjects demonstrated at least some open-set word recognition, a finding not previously reported in the literature for this device. All subjects performed better on the auditory-visual sentences than on either the auditory or visual conditions alone. These results contribute to the database on speech perception by cochlear implant users and show that open-set word recognition performance was somewhat better for these subjects using this implant than would have been predicted from the literature.