Physics at the threshold of hearing
(Phys.org) —The mammalian auditory system is one of the most sensitive detectors found in nature. Two kinds of cells, the inner and outer hair cells, work together to transduce mechanical vibrations into action potentials. Sound energy is detected and transmitted by the inner hair cells, while properties like gain and frequency selectivity, are controlled by the mechanical adjustments of vibrating outer hair cells. The business end of these cells, known as the hair bundle, is comprised of 30 or more stereocilia, that serve as the transducers. To date, physiologists are at odds to explain how the hair bundle can respond to mechanical stimuli whose energy is an order of magnitude below the energy level of the background thermal motion. A new study from Dolores Bozovic's lab at UCLA takes theoretical look at the mechanical vibrations of hair cells. Their analysis, recently published in Physical Review Letters, does not close the...