Sounds Better

In most cases, deafness is caused by the loss of hair cells in the inner ear that convert acoustic vibrations into nerve signals. Patients compensate by using cochlear implants with electrodes that stimulate the auditory nerve. But 'bionic ears' don’t restore hearing to normal sensitivity. Now, researchers have upgraded the performance of cochlear implants in guinea pigs by using the devices to deliver gene therapy. Pictured is a CT scan of a guinea pig’s skull with a cochlear implant. Electrical pulses from the implant create tiny holes in target cells, enabling the delivery of a gene that stimulates growth of new auditory nerves. Sure enough, nerve cells grew toward the implant’s electrodes, restoring the intimate connection that had been missing. The result was a dramatic improvement in hearing. If the method works in humans, it could help deaf people to experience something closer to the sharpness of normal hearing.

Written by Daniel Cossins

Daniel Cossins

Writer

As a freelance science writer, Dan's work has been published in award-winning magazines including BBC Focus, Wired UK, Cosmos, BBC Knowledge, BBC History and Men's Health.

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• Image by Biological Resources Imaging Laboratory, University of New South Wales, Australia
• Copyright held by University of New South Wales, Australia
• Research published in Science Translational Medicine, April 2014