On Mar. 31, 2025, a team of researchers from UC Berkeley and UC San Francisco announced they have unlocked a way to restore naturalistic speech for people with severe paralysis, marking a breakthrough in the field of brain-computer interfaces (BCIs).

This work solves the long-standing challenge of latency in speech neuroprostheses, the time lag between when a subject attempts to speak and when sound is produced. Using recent advances in artificial intelligence-based modeling, the researchers developed a streaming method that synthesizes brain signals into audible speech in near-real time.

As reported in Nature Neuroscience, this technology represents a critical step toward enabling communication for people who have lost the ability to speak. The study is supported by the National Institute on Deafness and Other Communication Disorders (NIDCD) of the National Institutes of Health.

The researchers also showed that their approach can work well with a variety of other brain sensing interfaces, including microelectrode arrays (MEAs) in which electrodes penetrate the brain’s surface, or non-invasive recordings (sEMG) that use sensors on the face to measure muscle activity.

This latest work brings researchers a step closer to achieving naturalistic speech with BCI devices, while laying the groundwork for future advances. The researchers also remain focused on building expressivity into the output voice to reflect the changes in tone, pitch or loudness that occur during speech, such as when someone is excited.