Tactile presentation of voice fundamental frequency as an aid to the perception of speech pattern contrasts

The perception of initial consonant voicing, final consonant voicing, pitch change, and word stress, was measured in six normal subjects, by speechreading alone, by tactile transmission of fundamental voice frequency alone, and by the two in combination. Two tactile displays were used: a single-channel (temporal) display and a 16-channel (spatial) display. By speechreading alone, all contrasts except initial consonant voicing were partially perceptible. By both tactile aids alone, all four contrasts were partially perceptable. The addition of tactile input to speechreading provided better performance than that obtained by speechreading alone. The multichannel display was found to be significantly more effective than the single-channel for perception of pitch rise/fall only.