AlterEgo

AlterEgo is a proprietary wearable silent speech output-input device developed by MIT Media Lab. The device is attached around the head, neck and jawline and translates muscular and neural activity into words on a computer without vocalization.

The device consists of seven small electrodes that attach at various points around the jawline and mouth to monitor electrical inputs to the muscles used for speech.

The device is not a form of brain–computer interface. Although often cited as a decoder of brain signals, the device primarily reads electrical activity from the muscles and not from the brain, making it closer to a form of electromyography than electroencephalography. The device requires the user to actively engage muscles in the throat and tongue, although demonstrations of the product conceal this fact to convey the impression of a static silent speech decoder.

The device uses statistical models to reconstruct vocal articulation from the recorded activity of muscles in the throat and the tongue, thereby bypassing the need for the user to produce sound using vocal cords. Similar products have existed since.

AlterEgo was designed by Arnav Kapur, a graduate student at MIT, and became public in 2018. The device was designed to help people with speech disabilities. In 2018, the device was presented at the Conference on Intelligent User Interfaces where the research team reported a 92% median word-accuracy rate.

• Silent speech interface
• Imagined speech / Subvocalization
• Intrapersonal communication

• MIT Alterego overview
• MIT news
• International Conference on Intelligent User Interfaces
• Fluid Interfaces group
• Transcribing the Voice in Your Head