More is Better: Cochlear Implants

Ivanhoe Newswire
Wednesday, February 14, 2007; 12:00 AM

By Vivian Richardson, Ivanhoe Health Correspondent

ORLANDO, Fla. (Ivanhoe Newswire) -- One cochlear implant can change the world for someone with significant hearing loss. Now, researchers say two cochlear implants, devices that transmit sound signals to the brain, can make an even bigger difference.

Children with two cochlear implants are better able to understand speech and locate the source of different sounds, according to researchers from the University of Wisconsin-Madison. In a study of 55 deaf children who received a second implant several years after their first, investigators report the children were able to adapt to two-sided hearing over time, as it takes time for the brain to adjust to two sound signals.

"Using two ears helps with you with acoustic functions in complex environments, such as when you're trying to listen to important sounds in noisy environments or when you're trying to localize sounds," Ruth Litovsky, Ph.D., told Ivanhoe. As an expert in binaural hearing, or hearing with two ears, Dr. Litovsky wanted to know more about the actual benefits of having two cochlear implants.

The children in Dr. Litovsky's study all received their second implant years after their first surgery. The delay between implants may make adjusting to hearing on two sides a longer process. "From what I hear from a lot of surgeons, nowadays they are able to put both implants in at the same time without too much difficulty," Dr. Litovsky said, though she added there is not a lot of data to indicate which choice is clearly better.

Otologist Joseph Roberson, M.D., from the California Ear Institute in Palo Alto, Calif., recommends two implants to his patients.

"I think the bottom line question is, 'What would I do with my own child,'" said Dr. Roberson. "I would definitely have two implants." Some restrictions do apply, however. Both ears must be anatomically able to support an implant. For some people, Dr. Roberson explained, a cochlear implant in one ear combined with a hearing aide in the other would work best.