Sound-to-Touch Sensory Substitution and Beyond
Novich, Scott David
Eagleman, David M
Doctor of Philosophy
Deafness affects an estimated 2 million people in the United States and 53 million worldwide. Cochlear implants are an effective therapeutic solution but suffer from a number of drawbacks: they are expensive, require an invasive surgery, have low efficacy in early-onset deaf adults, and not everyone who needs them may qualify for them. This creates a large unmet need for a solution that is affordable, non-surgical, and works in adults. "Sensory substitution"--the concept that information can be effectively mapped from one sense to another--has the potential to overcome all of these issues: it is non-invasive (and therefore inexpensive and less regulated) and leverages a developed sensory modality. This is realized by the understanding that (1) the nervous system ultimately encodes information as electrical signals and (2) the brain has the remarkable capability of cortical reorganization. Sensory substitution has previously been successfully applied as a solution for blindess via vision-to-touch substitutions. To this end, a sound-to-touch sensory substitution device, The Versatile Extra-Sensory Transducer (VEST), has been developed for this thesis-work as a means for overcoming deafness. The device consists of a smartphone that takes sound from the environment and converts this information to patterns of vibration on the torso. This occurs via an array of vibratory motors embedded on a vest that is worn under the user's clothing. It is capable of giving congenitally deaf individuals the ability to intuit speech. The development of this device serves as a motivating example for a more general guiding framework that applies to sensory substitution and augmentation devices.