At MIT, researchers are working on technology designed to improve tactile assist listening systems for the deaf. The system converts voice received by a microphone into vibration applied to the skin. Because modern mobile phones have all the necessary electronic components already built in (microphone, computer processor, vibrator), the hope is that with properly tuned mobile software, the system can be offered for next to nothing to the deaf around the world.
As part of their project, the researchers have done several studies on the frequency reception ability of the skin. The human ear can perceive frequencies up to 20,000 hertz, but for touch receptors in the skin, optimal frequencies are below 500 hertz.
Using a laboratory setup with a device that can provide distinct vibration patterns to three fingers simultaneously, Moallem has done preliminary studies of deaf people’s ability to interpret the vibrations from tactile devices.
This project was originally inspired by earlier studies Reed did on the Tadoma technique, a communication method taught to deaf-blind people. Practitioners of that method hold their hands to someone’s face while they are talking, allowing them to feel the vibrations of the face and neck.
Reed’s study, done about 20 years ago, showed that the deaf-blind subjects could successfully understand speech with this method — especially if the other person spoke clearly and slowly.
Press release: Devices aid the deaf by translating sound waves to vibrations
Images: Senior Research Scientist Charlotte Reed speaks while the device she helped develop converts the sounds into vibrations. Graduate research assistant Theodore Moallem uses the device to read her lips and feel the sounds.
