As sound waves entering 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 response to higher frequency
sound.
|
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 the first of
its kind, requiring compliance with 53 standards of quality and accountability,
verified by independent audit. 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
process. A.D.A.M. is also a
founding member of Hi-Ethics (www.hiethics.com) and subscribes to the principles
of the Health on the Net Foundation (www.hon.ch).
©Copyright 2005 A.D.A.M., Inc. Any duplication or distribution of the
information contained herein is strictly prohibited.
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.
|
