New Hearing Device Isolates Voices
New Hearing Device Isolates Voices

New Hearing Device Isolates Voices

An experimental hearing aid differentiates speakers and monitors the wearer’s brain activity to amplify the one she is trying to listen to.

May 17, 2019
Jef Akst

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Having a conversation in a loud room can be challenging, especially for those who wear hearing aids, which indiscriminately amplify voices. A new type of hearing aid, described yesterday (May 15) in Science Advances, could be the solution, by isolating individual speakers and using the brain activity of the wearer to selectively amplify the one voice he or she is trying to listen to.

The device, developed by Columbia University’s Nima Mesgarani and colleagues, is an upgrade from a system the team created in 2017, which had been pretrained to recognize individual voices. The latest version can now separate voices that it has never encountered before, The Guardian reports.

Currently, the device relies on electrodes implanted in the brain. The researchers tested it on three epilepsy patients who already had such electrode implants, playing audio recordings of multiple speakers while monitoring neural activity in the auditory cortex. A computer algorithm compared that brain activity with the spectrograms of the speech recordings to identify the voice that the patient was focusing on, then amplified that voice. “The brain waves of listeners tracked only the voice of the speaker they’re focusing on,” Mesgarani tells STAT.

Mesgarani and colleagues say they hope to create a noninvasive version of the hearing aid within the next five years, according to The Guardian, with electrodes placed in the ear instead of the brain to monitor for the voice that is capturing the listener’s attention.

Jesal Vishnuram, technology manager at the charity Action on Hearing Loss, tells The Guardian that testing the device in people with hearing impairments will be crucial, as it’s possible their brains will send less-clear signals about the focal voice of interest. “One of the reasons people struggle is that they often wait a long time before getting a hearing aid and in that time the brain forgets how to filter out the noise and focus on the speech,” she says. “This is really interesting research and I’d love to see the real world impacts of it.”