Turning Down Your Ears (broadcast Friday, January 23rd, 2009)

Diagram of the human ear. NIH image.

Do the ears have a built-in protection against loud sounds? New research finds that the ears may be able to turn down the volume to avoid damage. Writing in the journal PLoS Biology, researchers described genetically enhancing one protein found on sensory hair cells in mouse ears. The mutant mice with the enhanced form of this protein, a molecular receptor for the brain chemical, acetylcholine, were able to withstand loud noises better than regular mice (although they also weren't as sensitive to quiet noises to begin with.) The researchers say the finding could lead to drugs with a similar effect, artificially 'turning down' the volume in the ear to protect against loud noises. We'll find out more.