A stroke survivor speaks again with the help of an experimental brain-computer implant

Scientists have developed a device that can translate thoughts about speech into spoken words in real time.

Although it’s still experimental, they hope the brain-computer interface could someday help give voice to those unable to speak.

A new study described testing the device on a 47-year-old woman with quadriplegia who couldn’t speak for 18 years after a stroke. Doctors implanted it in her brain during surgery as part of a clinical trial.

It “converts her intent to speak into fluent sentences,” said Gopala Anumanchipalli, a co-author of the study published Monday in the journal Nature Neuroscience.

Other brain-computer interfaces, or BCIs, for speech typically have a slight delay between thoughts of sentences and computerized verbalization. Such delays can disrupt the natural flow of conversation, potentially leading to miscommunication and frustration, researchers said.

This is “a pretty big advance in our field,” said Jonathan Brumberg of the Speech and Applied Neuroscience Lab at the University of Kansas, who was not part of the study.

A team in California recorded the woman’s brain activity using electrodes while she spoke sentences silently in her brain. The scientists used a synthesizer they built using her voice before her injury to create a speech sound that she would have spoken. They trained an AI model that translates neural activity into units of sound.

It works similarly to existing systems used to transcribe meetings or phone calls in real time, said Anumanchipalli, of the University of California, Berkeley.