In 2004, pediatric audiologist Allyson Sisler-Dinwiddie plunged into a world of silence after a car accident damaged her hearing. Under the care of hearing researcher Rene Gifford, she became one of the first test subjects of a new technique to improve cochlear implants, devices that use electrodes to stimulate cells in the inner ear.

Produced and Directed by Emily Driscoll for NPR's Science Fridays. Camera: Jeff Nash