Brain-Controlled Hearing Aid Tested in First Human Trials

A hearing aid that decodes brain activity to determine which conversation a person wants to follow in a noisy room and then amplifies that voice has shown positive results in its first human trials. Researchers at Columbia University in New York reported the technology could lead to a new generation of hearing aids capable of addressing the cocktail party problem.

In this situation a noisy environment makes it difficult to focus on a single speaker. Conventional hearing aids amplify speech and reduce some background noise such as traffic but struggle when multiple people speak at once because they cannot isolate and enhance one voice.

In the study researchers recruited epilepsy patients who already had electrodes implanted in their brains to locate seizure sources. The electrodes measured brain activity while the patients tried to focus on one of two overlapping conversations played simultaneously.

By analyzing patterns of electrical activity from different clusters of brain cells the system identified which conversation a patient was attempting to follow. The system then adjusted the audio volume in real time increasing the selected conversation and decreasing the other.

One participant was so surprised by the change that she accused researchers of secretly adjusting the volume themselves. The findings published in the journal Nature Neuroscience provide the first direct evidence from human studies that brain-controlled hearing technology can improve speech perception in this manner.

The work builds on more than a decade of research into how the brain processes speech in crowded settings. Earlier studies identified distinctive patterns of brain activity linked to the conversation a person is paying attention to. This laid the foundation for a machine learning system capable of decoding auditory attention in real time.