Unit 4(D):

Hearing

Mr. McCormick A.P. Psychology

Do-Now

(Discussion) Why does one’s

voice

sound so

different

when it is

recorded

and

played back

?

Hearing 

Audition:

 The sense or act of hearing

The Stimulus Input: Sound Waves  Sound waves are compressing and expanding air molecules 

Frequency:

 The number of complete wavelengths that pass a point in a given time (for example, per second) 

Pitch:

 A tone’s experienced highness or lowness

The Stimulus Input: Sound Waves 

Amplitude:

 The height of a sound wave  Measures the energy/intensity of the wave  Loudness  Measured in decibels

Typical Decibel Levels

Loudness of Sound

120dB 70dB

The Ear

The Cochlea

Perceiving Pitch 

Place Theory:

 Links the pitch we hear with the place where the cochlea’s membrane is stimulated   Different frequencies vibrate in different places of the cochlea

Problem:

low-pitched sounds not localized 

Frequency Theory:

 The rate of nerve impulses traveling up the auditory nerve matches the frequency of a tone, enabling us to sense its pitch   The entire cochlea is believed to vibrate at a particular frequency

Problem:

high-pitched sounds (1,000 waves/second) travel faster than neurons

Locating Sounds

Because we have two ears, sounds that reach one ear faster than the other ear cause us to localize the sound.

Locating Sounds

 Why is it

difficult

to

locate

a sound when it occurs directly

ahead

,

behind

,

overhead

, or

beneath

us?



It is easier to locate a sound when it comes from either side of us; for this reason, to pinpoint a sound, we often need to cock our head, allowing each ear to receive a slightly different message.

Hearing Loss and Deaf Culture 

Conduction Hearing Loss:

 Caused by damage to the mechanical system that conducts sound waves to the cochlea  E.g. punctured eardrum 

Sensorineural Hearing Loss:

   Caused by damage to the cochlea’s receptor cells or to the auditory nerves “Nerve Deafness” Biological changes associated with heredity, aging, and prolonged exposure to ear-splitting noise or music

Hearing Loss and Deaf Culture 

Cochlear Implant:

 A device for converting sounds into electrical signals and stimulating the auditory nerve through electrodes threaded into the cochlea

Hearing Loss and Deaf Culture

 What are the

benefits

and

limitations

using

sign language

exclusively

in a of

hearing world

?

 What should the

hearing world’s

response

be to the use of

sign language

?

Review

 What is

determined

by the

frequency

sound? The

amplitude

? of a  Discuss the

path

in which

sound

between entering the

ear

travels and reaching the

brain

.

 How do we

locate

sounds

?

 What is the

difference

between

Conduction Sensorineural Hearing Loss

?

and

Homework



Unit 4 FRQ



Unit 4 Quiz:

“Sensation and Perception” 

Unit 4 Test:

“Sensation and Perception” 

Chapter 5 Outline:

Consciousness” “States of