Transcript document
Myers PSYCHOLOGY
Hearing
(Do you hear
what I hear?)
Hearing
Audition - the sense of hearing
Measured in decibels
Absolute threshold - zero
The Intensity of Some
Common Sounds
Audition
Amplitude (strength)
determines loudness
Frequency
the number of wavelengths
determines Pitch - a tone’s
highness or lowness
Ear is divided into 3 parts
Outer
Middle
Inner
See diagram
Audition- The Ear
1. Outer Ear - visible part & canal
2. Middle Ear - chamber between
eardrum and cochlea
HAS three tiny bones
HAS (like a piston - hammer, anvil, stirrup)
that concentrate the vibrations of the
eardrum on the cochlea’s oval window
Audition
3. Inner Ear
contains the cochlea, semicircular
canals, and vestibular sacs
Cochlea
coiled, bony, fluid-filled tube in the
inner ear through which sound waves
trigger nerve impulses
Hair cells line the basilar membrane
I am sound, where do I go?
Ear canal to Eardrum (vibrations)
Piston - HAS
Hammer
Anvil
Stirrup
Cochlea
Movement of Hair cells - basilar membrane
Auditory nerve
Neural message to the brain
Thalamus
Auditory cortex of Temporal lobe
How do we hear?
1. Place Theory (Helmholtz)
the theory that links the pitch we hear with
the place where the cochlea’s membrane is
stimulated;
best for high-pitched sounds
How do we hear?
2. Frequency Theory
the theory that the rate of nerve impulses
traveling up the auditory nerve matches the
frequency of a tone, thus enabling us to
sense its pitch;
best for low-pitched sounds
How We Locate
Sounds?
Locating sound
We locate sound by detecting differences
in the intensity (loudness) and timing
(speed) of the sounds received by each
ear
Why can’t I hear?
1. Conduction Hearing Loss
hearing loss caused by damage to
the mechanical system that
conducts sound waves to the
cochlea
Ex. Damage to eardrum, broken
HAS
Why can’t I hear?
2. Sensorineural Hearing Loss
hearing loss caused by damage
to the cochlea’s receptor cells or
to the auditory nerve
also called nerve deafness
Crunched the shag carpet - hair
cells perm. damaged
Audition
Older people tend to hear low
frequencies well but suffer hearing loss
for high frequencies
Amplitude required for
perception relative to
20-29 year-old group
1
time
10
times
100
times
1000
times
32
64
128
256
512
1024 2048 4096
8192 16384
Frequency of tone in waves per second
Low
Pitch
High
Cochlea implants - clip on Amazing brain
Sign language