Improvements to brain–computer interfaces are bringing the technology closer to natural conversation speed.
A brain-reading implant that translates neural signals into audible speech has allowed a woman with paralysis to hear what she intends to say nearly instantly.
Researchers enhanced the device — known as a brain–computer interface (BCI) — with artificial intelligence (AI) algorithms that decoded sentences as the woman thought of them, and then spoke them out loud using a synthetic voice. Unlike previous efforts, which could produce sounds only after users finished an entire sentence, the current approach can simultaneously detect words and turn them into speech within three seconds.
The findings, published in Nature Neuroscience on March 31, 2025, represents a big step towards BCIs that are of practical use.
Older speech-generating BCIs are similar to “a WhatsApp conversation”, says Christian Herff, a computational neuroscientist at Maastricht University, the Netherlands, who was not involved with the work. “I write a sentence, you write a sentence and you need some time to write a sentence again… It just doesn’t flow like a normal conversation.”
BCIs that stream speech in real time are “the next level” in research because they allow users to convey the tone and emphasis that are characteristic of natural speech, he adds.
For a full understanding and analysis of the research report, visit Nature Neuroscience at: https://www.nature.com/articles/d41586-025-01001-6