The long term purpose of this work is to develop an improved method of displaying tactile information for profoundly deaf individuals. The issue addressed is whether the tactile sensory system can benefit from encoding schemes that present data in a manner for analogous to the way the basilar membrane operates than is currently done. While the most advanced tactile methods include spectral analysis of the signals as part of the processing, what is displayed tactually is the envelope of the power spectrum encoded at a fixed frequency, typically 100 to 250 Hz. In this research we wish to study an approach in which additional information about the signal frequency content is retained in the tactile display. In our initial work we will test perceptual responses to signals consisting of low frequency tone pairs within the tactual range. Comparison will be made to responses using the more traditional processing paradigm. If it is found that this extra information appears to enrich perceptual experience, methods will be examined in the later stages of the work to determine how the entire speech frequency range can be processed to bring it into the bandwidth of the tactile system while still retaining the extra data. During this initial work, two processing paradigms that retain the desired information, each in a different format, will be examined.
