Unit 4D Hearing Mr Mc Cormick A P

Unit 4(D): Hearing Mr. Mc. Cormick 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 120 d. B 70 d. B

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 of using sign language exclusively in a hearing world? § What should the hearing world’s response be to the use of sign language?

Review § What is determined by the frequency of a sound? The amplitude? § Discuss the path in which sound travels between entering the ear and reaching the brain. § How do we locate sounds? § What is the difference between Conduction and Sensorineural Hearing Loss?

Homework § Unit 4 FRQ § Unit 4 Quiz: “Sensation and Perception” § Unit 4 Test: “Sensation and Perception” § Chapter 5 Outline: “States of Consciousness”