http://insciences.org/article.php?article_id=8327

MBL, WOODS HOLE, MA—The phrase “perk up your ears” made more sense last year after scientists discovered how the quietest sounds are amplified in the cochlea before being transmitted to the brain.

When a sound is barely audible, extremely sensitive inner-ear “hair cells”—which are neurons equipped with tiny, sensory hairs on their surface—pump up the sound by their very motion and mechanically amplify it. Richard Rabbitt of the University of Utah, a faculty member in the MBL’s Biology of the Inner Ear course, reported last spring on the magnification powers of the hair cell’s hairs.

Now, Rabbitt and MBL senior scientist Stephen Highstein have evidence that hair cells perform similarly in another context—in the vestibular system, which sends information about balance and spatial orientation to the brain.