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.

Speech occurs in a frequency range from about 250 hertz to 5,000 hertz. As people age the ability to hear higher frequency sounds fades first. ” This approach works when one person is speaking but does not separate overlapping voices. According to one researcher the cocktail party effect remains the biggest reason people dislike hearing aids.

Devices with directional microphones and noise-dampening algorithms provide partial help but have not fully resolved the issue.

Studies suggest that people who use hearing aids when needed are more likely to maintain better relationships with partners have better sex lives maintain more friendships preserve sharper minds and experience lower rates of loneliness and depression.

Nearly seven million people in the UK would likely benefit from a hearing aid but only about two million use them according to the charity Hearing Dogs for Deaf People.