Providing clues to deafness, researchers at Washington University School of Medicine in St. Louis have identified a gene that is required for proper development of the mouse inner ear.

In humans, this gene, known as FGF20, is located in a portion of the genome that has been associated with inherited deafness in otherwise healthy families.

"When we inactivated FGF20 in mice, we saw they were alive and healthy," says senior author David M. Ornitz, MD, PhD, the Alumni Endowed Professor of Developmental Biology. "But then we figured out that they had absolutely no ability to hear."

"Imagine you are playing ping-pong with a friend. Your friend makes a serve. Information about where and when the ball hit the table is provided by both vision and hearing. Scientists have believed that each of the senses produces an estimate relevant for the task (in this example, about the location or time of the ball's impact) and then these votes get combined subconsciously according to rules that take into account which sense is more reliable. And this is how the senses interact in how we perceive the world.

A new study by researchers from the Perelman School of Medicine at the University of Pennsylvania shows that declines in hearing ability may accelerate gray mater atrophy in auditory areas of the brain and increase the listening effort necessary for older adults to successfully comprehend speech.