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Suprasegmental and segmental speech perception tasks were administered to 8 patients with single-channel cochlear implants. Suprasegmental tasks included the recognition of syllable number, syllabic stress, and intonation. Segmental tasks included the recognition of vowels and consonants in three modalities: visual only, implant only, and visual + implant. Results were compared to those obtained from artificially deafened adults using a single-channel vibrotactile device. The patterns of responses for both suprasegmental and segmental tasks were highly similar for both groups of subjects, despite differences between the characteristics of the subject samples. These results suggest that single-channel sensory devices, whether they be cochlear implants or vibrotactile aids, produce similar patterns of speech perception errors, even when differences are observed in overall performance level.

Seven normally hearing adults were trained in the use of a multiple-channel electrotactile speech processor for 70 hours over a 6-month period. Two training strategies were used on each of the subjects: (1) analytic-plus-synthetic (AS), and (2) synthetic (S). The speech perception abilities of the subjects were assessed with closed sets of vowels and consonants, open sets of words and sentences, and speech tracking, for the tactile-plus-lipreading, tactile, and lipreading conditions. The subjects were tested on three separate occasions: (1) at the beginning of the study, (2) after 35 hours of training, and (3) after a further 35 hours of training. Wilcoxon matched-pair signed-ranks (MPSR) tests showed that improvements observed with both the AS and S strategies were significantly (p less than .05) greater than zero for most tests and conditions. The Wilcoxon MPSR test showed that the difference in improvements between the training strategies was significant for only the vowel and consonant tests in the tactile condition.

The intelligibility of two speech synthesizers [ECHO II (Street Electronics, 1982) and VOTRAX (VOTRAX Division, 1981)] was compared to the intelligibility of natural speech in each of three different contextual conditions: (a) single words, (b) "low-probability sentences" in which the last word could not be predicted from preceding context, and (c) "high-probability sentences" in which the last word could be predicted from preceding context. Additionally, the effect of practice on performance in each condition was examined. Natural speech was more intelligible than either type of synthesized speech regardless of word/sentence condition. In both sentence conditions, VOTRAX speech was significantly more intelligible than ECHO II speech. No practice effect was observed for VOTRAX, while an ascending linear trend occurred for ECHO II. Implications for the use of inexpensive speech synthesis units as components of augmentative communication aids for persons with severe speech and/or language impairments are discussed.