Separating signal and noise in vibrotactile devices for the deaf

This paper briefly reviews a series of experiments demonstrating that a sound-to-touch transform of signal and noise may be perceptually separated by providing tactile cues for sound localization. Following this, three experiments are reported in which it is shown that such stereotactile cues are available if two vibrotactile devices (Minifonators, produced by Siemens Co. Ltd.), are used instead of one. With this system, subjects were able to attend to a target signal (male voice) in white noise and when a female voice was presented simultaneously. This ability depended upon a sufficient spatial separation of the target and noise in acoustic space. These findings appear to have applications in the design of tactile hearing aids and cochlear implants when used in noisy environments or when more than one sound is present.