Physiological noise level enhances mechanoelectrical transduction in hair cells

Stochastic resonance has been observed in several biological systems. However, an important issue not fully addressed is whether optimal noise levels correspond to the noise levels found under physiological conditions. We have found that mechanoelectrical transduction in hair cells is enhanced by Brownian motion of the cellsʹ sensory organelle, the hair bundle. Our estimates suggest that Brownian motion provides a nearly optimal noise level. This suggests that stochastic resonance might play a physiological role in the detection of weak auditory signals.