© Richard Goldman October 9, 2006 Module 10 Hearing and Other Senses Chapter 3, Pages 108-120 Essentials of Understanding Psychology- Sixth Edition PSY110 Psychology © Richard Goldman October 9, 2006

Ear Converts sound waves into nerve pulses Senses motion Helps maintain balance

Ear Structure Outer Ear Inner Ear Oval window Cochlea Basilar membrane Pinna Auditory canal Eardrum (Tympanic membrane) Middle Ear Ossicles (bones) Hammer Anvil Stirrup Eustachian tube Inner Ear Oval window Cochlea Basilar membrane Hair cells Auditory nerve Semicircular canals (3) – motion sensors Otoliths- orientation & acceleration sensors

Orientation & Acceleration Otoliths

Sound Compression wave (not transverse) that travels through a medium Human can hear sound in the range of 20-20,000 Hz (cycles per second) – pitch Amplitude – Intensity of sound – measured in decibels (a 10X logarithmic scale) – sounds greater than 120db is painful Sensitivity –

Sound Waves

Sound Localization Differences in intensity and time differences between sound reaching each ear help the brain determine what direction the sound came from

Theories of Hearing Place Theory – Excitation of specific locations on the basilar is responsible for frequency discrimination Frequency Theory – Excitation across the basilar membrane in sync with the sound is responsible for frequency discrimination

Hearing Loss Damage due to: My be corrected with: Physical damage – cotton swab (Q-tip) Illness – Mumps Prolonged exposure to loud sound Brief exposure to very loud sound My be corrected with: Hearing aid – auditory discrimination is often a problem Cochlear implant

Deaf Culture Some people believe that belonging to a deaf culture is just a good as belonging to a hearing culture.

Olfaction - Sense of Smell Humans can detect > 10,000 separate smells 1,000 different specialized types of olfactory cells Pheromones – secreted odors use to communicate

Gustation - Sense of Taste Taste results from combinations of stimulating 4 different types of taste buds located on tongue, in mouth, and throat. Sweet Sour Salty Bitter Humans have about 10,000 different taste buds Each taste bud is replaced every 10 days

Interrelation of Taste and Smell The perception of taste often relies on the perception of smell to identify a food substance

Skin Senses: Touch Pressure Temperature Pain

Pain Gate-control theory - Pain is a perception under control of the brain Treatments: Medication Electro stimulation of the nerve Light Therapy Hypnosis Surgery Cognitive Restructuring - Rewrite of the pain “script”