Transcript Auditory Senses

Auditory Senses
You better be listening…
Sound Waves
Amplitude
 Height
of wave
 Determines
how loud
Wavelength
 Determines
pitch
 Peak to peak
High frequency, waves packed = high pitch
Low frequency, loose waves = low pitch
How we hear: Outer Ear
 The
pinna channels
sound waves into the
ear
 Naturally blocks out
‘background noise’
 Sound waves travel
through the auditory
canal and vibrates
the ear drum
How we hear: Middle Ear
 The
ear drum vibrates and pulses your
ossicles
Ear Drum
Cochlea
Ossicles
vibrate the cochlea
Transduction occurs
When
hair cells move in cochlea, it
turns sound waves
(vibrations) into
neural impulses
Video of Natural Earing (1:05)
Major Divisions of the Ear
 Outer

Ear
acts as a funnel to direct sound waves towards inner
structures
 Middle

consists of three small bones
(or ossicles) that amplify the sound
 Inner

Ear
Ear
contains the cochlea that actually transduces sound
into neural response
Hearing Loss
 Conduction
Hearing Loss
 Physical damage to ear
drum or ossicles
 Nerve
Hearing Loss
 2 ways to damage
cochlear hairs
 Can’t
regenerate hair
growth
Sound Location
 Figuring
out where sound is coming from
 .000027 seconds
How we do perceive loud?
number
of hair cells that move in the
cochlea
How do we perceive pitch?
Place
theory
Where the hairs are located
correspond to pitch
High pitch; sensitive near the
beginning
Low pitch; sensitive towards the end
Frequency theory
number of impulses fired from the
auditory nerve