Tactile speech reception using augmented Tadoma

Results obtained with Tadoma have set a new standard for the tactile communication of speech [Reed et al., J. Acoust. Soc. Am. 77, 247–257 (1985)]. These results, however, are inferior to those obtained in the normal auditory domain: they are roughly comparable to those obtained by normal‐hearing subjects listening to speech in signal‐to‐noise ratios of 0–6 dB. The goal of the current research is to augment Tadoma with supplementary tactile displays to improve the perception of speech segments. Among the supplementary displays investigated were a vibrotactile display of tongue contact with the hard palate and a vibrotactile display of the short‐term speech spectrum. The tongue‐palate‐contact display was effective for improving the discriminability of pairs of consonants difficult to distinguish through Tadoma; however, neither this display nor the multichannel spectral display proved to be effective for augmenting vowel discriminability. A third approach to augmenting Tadoma currently under investigation involves the tactile reception of cued speech. [Work supported by NSF.]