Visual and tactual perception of syllable number in sentence stimuli.

The purpose of this study was to determine whether suprasegmental information could be perceived by artificially deafened subjects via the Multipoint Electrotactile Speech Aid (MESA) so as to enhance the visual perception of connected discourse. This study compared subjects' untrained ability to perceive the number of syllables in sentence stimuli in three conditions: Visual Alone (VA), Tactile Alone (TA), and Tactile plus Visual (TV). Five adults tapped the temporal pattern of stimuli using a telegraph key. Stimuli consisted of 1-, 3-, 5-, and 7-syllable meaningful sentences and 5- and 7-syllable (nonmeaningful) second-order sentences. The subjects perceived correctly a mean of 37% of the stimuli in the TA condition, and approximately 60% of the stimuli in the VA and TV conditions. Three possible explanations are offered to account for these results: (1) the limitations of the MESA's electrocutaneous transform of the speech signal, (2) the sensory limitations of the skin, and (3) the absence of extensive training.