Narrator: This is Science Today. Thousands of adults and children worldwide have cochlear implants. These prosthetic medical devices are for people with hearing loss who basically receive little or no benefit from regular hearing aids. Jan Larky, an audiologist at the University of California, San Francisco, says in that respect it's kind of a last resort.
Larky: What you would go to if you've tried all the appropriate new technology in hearing aids and they're not giving you speech understanding and clarity. So it's designed for people who have what most people call nerve deafness, even though their nerve function's fine, so it bypasses the damaged parts of the ear and delivers electrical stimulation directly.
Narrator: Patients must have a hearing level of seventy decibels, have previously used hearing aids and have normal inner ear anatomy.
Larky: The implant is designed to last a hundred years at least and not fail. And the externals will always be changing and so a person will be able to upgrade to whatever technology comes out in the future.
Narrator: For Science Today, I'm Larissa Branin.