Listen to the ear's song

Auditory perception is shaped by the "microphone" cells of the inner ear (hair cells). The sound stimulus causes these cells to vibrate mechanically, transforming them into a nervous signal that then spreads to the brain. Curiously, the ear is not only a sound receiver; it can also emit sounds!

Some live experiments will show that these sound emissions betray a mechanical activity that amplifies the sensitivity and refines the selectivity of sound detection.