The long-term objective of this work is to develop an improved method of displaying tactile information for the deaf. The issues addressed are number of channels used for displaying the desired information, the content (ENCODING) of the displayed signal and, as a secondary issue, the relative noise immunity of two different processing approaches. The specific processing/display types to be examined are: 1) A supplemented formant tracker in which an additional wideband signal will be supplied to the user through an extra specially designed transducer; 2) A formant tracker processor which uses pitch lowered driving signals instead of the more usual single tone encoding; 3) A vocoder which, again, uses pitch lowered driving signals instead of the more usual single tone encoding; and 4) a 24-channel formant tracker using processing similar to that now used by the Tactaid VII (a 7-channel wearable device) but with better resolution. An additional task will be to compare the noise resistant properties of two formant trackers; one using zero-axis analysis techniques while the other uses filter-based analysis techniques. If the results of these studies show promise or any one of these new approaches, Audiological Engineering would undertake the commercial development of the necessary associated technologies in order to make available the more advanced kind of tactile aid for the deaf.
