Skip navigation

Hearing and the cochlea

This video plays in QuickTime format. To view the video, download and install the Apple QuickTime player at: http://www.apple.com/quicktime/download/.

As sound waves enter the ear, they travel through the outer ear, the external auditory canal, and strike the eardrum causing it to vibrate.

The central part of the eardrum is connected to a small bone of the middle ear called the malleus (hammer). As the malleus vibrates, it transmits the sound vibrations to the other two small bones or ossicles of the middle ear, the incus and stapes.

As the stapes moves, it pushes a structure called the oval window in and out. This action is passed onto the cochlea, which is a fluid-filled snail-like structure that contains the receptor organ for hearing.

The cochlea contains the spiral organ of Corti, which is the receptor organ for hearing. It consists of tiny hair cells that translate the fluid vibration of sounds from its surrounding ducts into electrical impulses that are carried to the brain by sensory nerves.

As the stapes rocks back and forth against the oval window, it transmits pressure waves of sound through the fluid of the cochlea, sending the organ of Corti in the cochlear duct into motion. The fibers near the cochlear apex resonate to lower frequency sound while fibers near the oval window respond to higher frequency sound.

Update Date: 11/10/2012

Updated by: David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine. Also reviewed by A.D.A.M. Health Solutions, Ebix, Inc., Editorial Team: David Zieve, MD, MHA, David R. Eltz, Stephanie Slon, and Nissi Wang.

A.D.A.M Quality Logo

A.D.A.M., Inc. is accredited by URAC, also known as the American Accreditation HealthCare Commission (www.urac.org). URAC's accreditation program is an independent audit to verify that A.D.A.M. follows rigorous standards of quality and accountability. A.D.A.M. is among the first to achieve this important distinction for online health information and services. Learn more about A.D.A.M.'s editorial policy, editorial process and privacy policy. A.D.A.M. is also a founding member of Hi-Ethics and subscribes to the principles of the Health on the Net Foundation (www.hon.ch).

The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed physician should be consulted for diagnosis and treatment of any and all medical conditions. Call 911 for all medical emergencies. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. Copyright 1997-2014, A.D.A.M., Inc. Duplication for commercial use must be authorized in writing by ADAM Health Solutions.

A.D.A.M Logo