Hearing research at the Waisman Center

More than 278 million people are affected by hearing loss caused by damaged hair cells in the inner ear that process sound to the brain. Waisman Center scientists work to research novel treatments and therapies for individuals with hearing loss that include stem cell research and cochlear implants.

Ruth Litovsky, PhD
Ruth Litovsky, PhD

Currently, the most common treatment for profound hearing loss, for both children and adults, is a cochlear implant (CI). A CI is a small electronic device that can provide a sense of sound to a person who is profoundly deaf or severely hard-of-hearing. One part of the implant sits behind the ear and a second part is surgically placed under the skin. Ruth Litovsky, PhD, directs the Binaural Hearing & Speech Lab where research focuses on the ability of humans to function in complex auditory environments.

“We’ve established world-class environment for training young scientists to study how children and adults can hear, perceive and learn in noisy environments,” says Litovsky. “Our research findings are integrated into clinical practice in the United States and abroad, and this research is leading to improvement in treatment of patients who are deaf and use cochlear implants.”

In order to understand how the brain determines the location and the content of important sounds, Litovsky studies hearing in children and adults with hearing loss and with typical hearing. In particular, she focuses on people who are deaf and use CIs. Litovsky evaluates binaural hearing (being able to integrate information that the brain receives from the two ears) in patients who have CIs in both ears. Binaural hearing is known to help with the ability to listen in noisy, complex auditory environments, and to localize sound sources. Litovsky’s lab investigates whether CI users can benefit from having two (bilateral) CIs and whether, for children, having bilateral CIs at a young age offers unique advantages.

“In the next five to 10 years, we hope to extend these research tools to patients affected by other perceptual, cognitive and developmental disorder,” says Litovsky.

Future treatments for hearing loss hope to regenerate inner ear hair cells to restore hearing without the use of a cochlear implant. Samuel Gubbels, MD, a Waisman Center investigator and surgeon who specializes in cochlear implants, uses induced pluripotent stem (iPS) cells to model the development, disease and regeneration of inner ear hair cells. The ideal treatment for hearing loss would be to replace the elements of the inner ear which have been lost due to loud noise, ageing, medications, or hereditary causes.

Su-Chun Zhang, MD, PhD
Su-Chun Zhang, MD, PhD

“Stem cells are important tools in our arsenal to determine why hearing loss occurs and how we can prevent and repair it in the future,” says Gubbels.

In collaboration with Su-Chun Zhang, MD, PhD, Gubbels creates a method to separate of iPS cells into auditory hair cells and other inner ear cell types. In his lab, Gubbels evaluates the ability of these cells to integrate into the appropriate areas of the inner ear. This research provides important insight into how iPS cells can be used to model inner ear disease and realistically pursue cell-based therapies for hearing loss.

“My hope is that through this research, we can improve the quality of life for children and adults living with hearing loss.”

The Waisman Center hosts an annual community outreach event, Day with the Experts: Cochlear Implants that presents the latest advances in cochlear implant research and clinical treatments with presentations from leading scientists and a panel of experts including individuals with cochlear implants and family members. This year’s event will be held on May 30. For more information visit waisman.wisc.edu/events-experts-ci-May2015.htm.

For more information about hearing research and events at the Waisman Center, visit waisman.wisc.edu.