A voice-synthesis neuroprosthesis based on a brain–computer interface (BCI) has restored instantaneous, natural-sounding speech to a man with amyotrophic lateral sclerosis (ALS), according to a new report in Nature.
The study participant was BrainGate2 participant T15, a man with ALS who had some residual speaking ability but had difficulty producing intelligible speech. The research team implanted four arrays containing a total of 256 microelectrodes into the precentral gyrus of T15’s brain and used these arrays to record neural activity as he attempted to speak a series of phrases displayed on a screen. This activity was decoded and fed into a voice synthesizer, which generated synthetic speech that closely resembled T15’s pre-ALS voice. Transcription of the synthesized speech by naive human listeners revealed considerable improvements in intelligibility compared with the participant’s own residual speech.
