Identification of speech sounds displayed on a vibrotactile vocoder.

A vocoder‐type speech analyzer interfaced to the tactile display of an Optacon was used to investigate how subjects learned, over a six‐week period, to identify the vibrotactile patterns of different speech signals. Closed sets of four vowel durations, three different vowels, and four spondee words constituted the test material. Learning to identify vibrotactile patterns required many hours of training. Subjects in this study showed significant improvement in the identification of all three types of speech signals, especially the vowel durations and spondee words. Tests for transfer at the end of training showed that shifting the locus of stimulation did not result in decrement in performance.