Sound/Hearing Sensation & Perception

The ear is divided into the outer, middle and inner ear.

The sound waves travel down the auditory canal to the eardrum.

Eardrum = tight membrane that vibrates when struck by sound waves. The Ear Eardrum = tight membrane that vibrates when struck by sound waves.

The Ear Bones of the middle ear = the hammer, anvil, stirrup which vibrate with the eardrum.

The Ear Cochlea = a coiled, body, fluid-filled tube in the inner ear through which sound waves trigger nerve impulses.

The Ear Auditory nerve = nerve which sends the auditory message to the brain via the thalamus.

Characteristics of Sound Frequency corresponds to the perceptual term pitch. Amplitude corresponds to the perceptual term loudness (volume). Complexity corresponds to the perceptual term timbre (quality).

Properties of Sound Wavelength – Hertz (Hz) – waves (cycles) per second Pitch (frequency) High Low Sound has three aspects: pitch (frequency), loudness, and timbre (purity). L4.47

Properties of Sound Wavelength – Hertz (Hz) – waves (cycles) per second Pitch (frequency) High Low Loudness Timbre (purity) Sound has three aspects: pitch (frequency), loudness, and timbre (purity). L4.47

Properties of Sound Complexity: A violin and a piano sound different, even though they may be playing the same note. Mastering3.22

Perceiving Pitch Place Theory The pitch we hear is linked to a particular place where the cochlea’s membrane is stimulated

Perceiving Pitch Frequency Theory The rate of nerve impulses traveling up the auditory nerve matches the tone Problem: individual neurons can’t fire faster than 1000 times per second, but we can hear frequencies above that. Solution: The volley principle. Neural cells alternate firing to achieve faster responses.

Characteristics of Sound Amplitude corresponds to the perceptual term loudness (volume). The #1 cause of hearing loss is exposure to loud noise.

L4.49

Hearing Loss Sensorineural Hearing Loss Conduction Hearing Loss Caused by damage to the mechanical system that conducts sound waves to the cochlea Sensorineural Hearing Loss Caused by damage to the cochlea’s receptor cells or to the auditory nerve Teen hearing loss has risen by one-third since the early 1990s. 1 in 5.

Hearing Loss Hearing Aids Increase amplitude on specific frequencies Cochlear Implants convert sounds into electrical signals and stimulate the auditory nerve.

Grayson Clamp hears for 1st time Cochlear implant example #1 Anna’s Activation Type Cochlear implant into youtube’s search box for more.

Locating Sounds Sound waves strike one ear sooner and more intensely than the other.

Taste Sensation

Taste Gustation - the sensation of a taste. LO 7.6 How do the senses of taste and smell work, and how are they alike? Gustation - the sensation of a taste. Papillae – small bumps on the tongue that have taste buds in them. Taste buds - taste receptor cells in mouth; responsible for sense of taste.

Taste Five primary taste sensations have been identified. ­­ – Sweet – Sour ­­ – Salty ­­ – Bitter ­­– Umami 3.10 How do we detect the primary taste sensations?

Taste Individuals vary in their capacity for experiencing taste sensations. Nontasters (fewer tastebuds) unable to taste certain sweet and bitter compounds Supertasters (more tastebuds) taste sweet and bitter compounds with far stronger intensity than other people Phenylthiocarbamide (PTC) paper 3.10 How do we detect the primary taste sensations?

Smell Olfaction Olfactory bulbs At least 1,000 olfactory receptors. Sense of smell. Olfactory bulbs Areas of the brain specifically dedicated to receive information from the olfactory receptor cells. At least 1,000 olfactory receptors. Each have about a half dozen to a dozen little “hairs” (ciliar) that project into the cavity and send signals to the brain.

How do we smell?

Assignment Complete the Ear Diagram handout Psy – 1: blue book = page 92 AP: green book = page 196