Cochlea (IMAGE) Uppsala University Caption Ear membrane and auditory nerve in the cochlea. The octave bands have been given different colours. Humans can perceive frequencies from 20 Hz (the top of the coil) to 20,000 Hz (the base of the coil). The image also shows the round window, the oval window where sound enters and the facial nerve. Credit Hao Li Usage Restrictions This image may only be used when reporting about Hao Li's research. License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.