Research Communications

Perfect Pitch 

Software may improve hearing implants

Dec. 15, 2009

No rising and falling of chatter- ing voices fills your ears, no music in the distance dances into your head. That’s what it’s like for peo- ple living with cochlear implants: muffled words and sounds are the closest technology comes to living in a world with hearing. But Ohio University doctoral student Ning Zhou is striving to improve the way sounds are processed through these implants, with support from a new grant from the National Institutes of Health (NIH).

Cochlear implants are electronic devices for the profoundly deaf. The implants are placed into the ears via surgery and stimulate the auditory nerve. According to the Food and Drug Administration, by the end of 2008, more than 150,000 people around the world had received the implants.


Illustration: Christina Ullman, Ullman Design

Zhou is developing a new speech processing strategy for the software in the bilateral implant devices. The strategy would affect how sounds enter the ears in order to improve the percep- tion of pitch. Different sounds would reach each ear and com- bine to allow the implant user to hear more variations of pitch. In current bilateral implants, the same sound information travels to both ears.

“I want the electrodes in each ear to get unique information so it can fuse for a much better frequency resolution. If that works, it will contribute greatly to the field,” Zhou says.

A higher frequency resolution provides better pitch discrimi- nation. This could be especially beneficial for users who speak tonal languages. In these languages, such as Mandarin Chinese, Zhou’s native tongue, the same syllable spoken in various pitches has different meanings. Those who can’t distinguish pitch have a hard time appreciating music or singing on key, explains Zhou, who works with Li Xu, an Ohio University associate professor of hearing, speech, and language sciences.

The NIH National Research Service Award for Individual Predoctoral Fellows, which Zhou received this spring, will help her advance the research, which she hopes to commercialize one day.

Zhou previously has studied the singing abilities of children and music and tone perception of adults in China, with and with- out cochlear implants. In another project, she’s determining what factors contribute to how well cochlear implants impact tonal development in the children.

Throughout her work, she’s observed the potentially life- changing impact of cochlear implants on people with hearing impairments.

“People who were used to reading lips for communication, people who could never use a telephone, people who were isolated from their communities now can hear,” Zhou says. “Because of that, they can have a better quality of life.”

By Jaclyn Lipp

This article will appear in the Autumn/Winter 2009 issue of Perspectives magazine. 

For more information about Ning Zhou, visit: