Abstract
Although the amplitude of tympanic membrane vibrations is only a few nanometers when we speak in a low voice, we can understand clearly what is being said. This is speculated to be due to the cochlear amplification which is based on outer hair cell (OHC) motility. However, the mechanism of OHC motility in the cochlea is unclear. In order to understand this mechanism, motility of an isolated OHC in response to step voltage stimuli is measured using a high-speed video system. Results indicate that the generation force of the short OHC taken from the basal region of the cochlea was larger than that of the long OHC taken from its apical region.
