Speechreading enhancement: A comparison of spatial-tactile display of voice fundamental frequency (F-0) with auditory F-0

In two experiments, subjects repeated video-recorded sentences presented via speechreading with and without enhancement by a sensory input derived from the acoustic speech signal. Enhancement was measured as percentage increase in recognized words. In experiment 1, tactile presentation of fundamental frequency (F-0) provided, after training, for three of four postlingually deafened adults a mean enhancement of 11%. In experiment 2, using six hearing adults, the auditory presentation of F-0 provided a mean enhancement of 50%. This value fell, but only to 37%, when the F-0 signal was derived from the processor of the tactile aid used in experiment 1. From these experiments it can be concluded that the unexpectedly small enhancement found in experiment 1 is probably due both to the fact that this tactile aid was not providing effective access to all of the information available in the F-0 contour and to limitations related to the tactile processing ability of the kinaesthetic system. (C) 1996 Acoustical Society of America.