A brain-computer interface is restoring the ability to speak to a man living with ALS, translating his brain signals into words in a matter of seconds. The man, identified in the study as Casey, has electrodes that read his brain activity as he attempts to talk, turning his intended words into speech.
The electrodes attach directly to his skull and record his brain activity. As Casey tries to speak, the system captures those signals and maps the patterns to phonemes, the individual sound units that make up spoken words.
The decoded words then appear as text on a computer screen and are played aloud through its speakers. According to the research team, the system can identify Casey's intended words with 97% accuracy, and it does so in just seconds.
To make the output sound like Casey rather than a generic machine voice, the team drew on old audio recordings of him from before his condition took away his ability to speak. The recreated voice echoes the way he used to sound.
Neuroscientist Sergei Stavisky, part of the team behind the work, described how the technology records patterns of brain activity and matches them to the sounds Casey is trying to produce. It was that team's approach that reached 97% accuracy in identifying his words.
For Casey, the impact has been profound. He said the system lets him communicate in his natural way more than any other technology he has experienced, describing a life more full of dynamic action, with friends, family and colleagues.
Researchers say the work offers hope for others living with ALS, giving people who have lost their voice a new way to communicate. By restoring that connection, the technology could help patients stay close to the people around them.