Probing Cochlear Resonators Using a New Microchamber

The mammalian cochlea is an acoustic spectrum analyzer and pressure transducer with a remarkable operating range, both in frequency and amplitude (Fettiplace & Hackney, 2006). A young, healthy human ear can capture sounds of 40 to 20,000 Hz in frequency and 20 μPa to 20 Pa (0 to 120 dB sound pressure level) in amplitude. One of the most significant achievements in decades regarding cochlear research is the identification of the cochlear amplifier. Tiny acoustic vibrations are amplified in the organ of Corti (OC)–sensori-eptithelium in the cochlea. Mechano-transducer receptors in the OC, called the outer hair cells, have been identified as the cellular actuators that provide energy to boost small pressure waves. However, the underlying mechanism of this amplification is still unclear.