Vibrotactile perception of segmental features of speech: a comparison of single-channel and multichannel instruments

This experiment compared the recognition performance of artificially deafened listeners for segmental stimuli presented through a single-channel tactile device and through a 24-channel vocoder. Both consonant and vowel stimuli were tested under visual only, tactile only, and visual + tactile conditions. Each subject received a pretest, eight 2-hr training sessions, and a posttest. Results indicated no significant differences between subject's overall recognition performance with two different tactile devices. Analysis of consonant confusions showed that both devices transmit the features of voicing, manner, and place of articulation in a similar fashion. In contrast to an earlier study on suprasegmental features by Carney and Beachler (1986), these results do not support the notion that preservation of the waveform envelope of speech is necessary for the transmission of segmental features of speech. These results also suggest that tactile perception of segmental features may not be altered significantly by the tactile array chosen.