Download Module 13 Hearing - Northside Middle School

Audition- sense of hearing
Parts of the ear
 Middle ear- chamber between the ear drum and the cochlea containing 3 tiny bones (hammer,
anvil, and stirrup) concentrates the vibrations of the eardrum on the cochlea’s oval window
 Inner ear- the innermost part of the ear containing the cochlea, semicircular canals, and vestibular
sacs
 Cochlea- coiled, bony, fluid- filled tube in the inner ear through which sound waves trigger neural
impulses
How sound is transferred
 Sound waves travel through auditory canal to eardrum
 Middle ear transmits the vibrations through the piston into the cochlea in the inner ear
 Vibrations cause the cochlea’s membrane to vibrate fluid inside of it
 Fluid ripples bend the hair cells on the nerve fibers that are part of the auditory nerve
Theories
 Place Theory- theory that links the pitch we hear with the place where the cochlea’s membrane is
stimulated
 Frequency theory- theory that the rate of nerve impulses traveling up the auditory nerve matches
the frequency of a tone, enabling us to sense pitch
Hearing loss
 Conduction- hearing loss caused by damage to mechanical system that transfers sound waves
 Sensorineural- hearing loss caused by damage to cochlea’s receptor cells or the auditory nerves
Ear Anatomy
Ribbon candy: Sound Wave
Sound waves travel through
inner ear canal and cause the
eardrum to vibrate, starting
the audition process
Amplitude
Frequency
Review Video