UIUC PSYC 230 Exam #2

Sound Stimulus

the periodic variations in air pressure traveling out from the source of the variations

Sound waves

the waves of pressure changes that occur in the air as a function of the vibration of a source

Medium of sound

* Air or Water: Sound travels four times faster in water than air

Sound travels fast, but slower than light

Pure tones

Air pressure changes to follow a sine wave pattern

Amplitude

Difference between maximum sound and minimum sound pressures

Loudness

perceptual experience of amplitude

Frequency

the number of cycles in a sound stimulus that occur in 1 second

Pitch

the subjective experience of frequency

Children and Young Adults range of hearing

20 - 20,000 Hz

Over 50 years old range of hearing

20 - 12000 Hz

Pinna

collects sound waves

External auditory canal

Conducts sound in tympanic membrane & amplifies specific sound frequencies

Tympanic Membrane (eardrum)

a thin, elastic diaphragm at the inner end of the auditory canal that vibrates in response to the sound waves that strike it; forms an airtight seal between the outer ear and the middle ear

Ossicles

conduct sound mechanically to amplify sounds

Malleus

hammer

Incus

anvil

Stapes

stirrup

Eustachian tube

connects the middle ear with the pharynx & equalizes air pressure on either side of the eardrum

Tensor Tympani & Stapedius

Tense in the presence of loud noises

Inner ear

transduce sound into neural signal

Cochlea

houses the hair cells

Canals within the Cochlea

* tympanic
* Middle
* vestibular

Membranes within the Cochlea

* Reissner's
* Basilar
* Tectorial

Basilar Membrane

A structure that runs the length of the cochlea in the inner ear and holds the auditory receptors, called hair cells.

Organ of Corti

Center part of the cochlea, containing hair cells, canals, and membranes

Inner hair cells

convey info to brain

Outer hair cells

receive info from brain

Coding of small amplitude sounds

hair cells bend to smaller degree

Coding of large amplitude sounds

hair cells bend to larger degree

Place code theory

different locations along the basilar membrane respond to different frequencies

Characteristic frequency

The frequency at which a neuron in the auditory system has its lowest threshold.

Temporal code theory

the view that frequency representation occurs because of a match between sound frequency and the firing rates of the auditory nerve

Coclear nucleus

serves as a lateral inhibition function

Trapezoid body

important for determining direction of sound

Superior Olive

receives info from both ears, critical for sound localization

Primary auditory cortex

the region of the superior temporal lobe whose primary input is from the auditory system

Tonotopic organization

similar frequencies are coded by neurons close to each other in the brain

what pathway

basis for speech perception and music perception

Where pathway

location of sound in space

conductive hearing loss

sound does not properly arrive to the cochlea

otosclerosis

calcification of the ossicles, making them less conducive to sound

sensorineural hearing loss

damage to cochlea, auditory nerve, or primary auditory cortex

Tinnitus

people perceive sounds when none are present

harmonic spectrum

the spectrum of a complex sound in which energy is at integer multiples of the fundamental frequency

missing fundamental effect

The pitch listeners hear corresponds to the fundamental frequency, even if it is missing

Timbre

psychological sensation that combines tonality and harmonic spectrum of a sound as whole

sound localization

we can locate sounds based on which ear they strike first

interaural level difference

sound coming from one side of the body is more intense at the closest ear because of the attenuation of the sound wave as it passes through the head

interaural time difference

the difference in time between a sound arriving at one ear versus the other

Interaural Time difference in the media superior olives

The cone of confusion

A region of positions in space where all sounds produce the same time and level (intensity) differences (ITDs and ILDs).

Elevation perception

Spectral Shape cue

Reverberation

repeated echoes of sound

Echo

a reflected sound wave

Spatial segregation

Brain compares arrival times of sounds that go together, can determine direction and number of sound sources

Temporal Segregation

the process whereby sounds that are linked in time are grouped together, whereas sounds that are not correlated with one another are not grouped together

Spectral Segregation

the process whereby sounds that overlap in harmonic structure are grouped together, whereas sounds that do not overlap in harmonic structure are not grouped together

Vestibulo-spinal reflex

-allows for postural control and body orientation

Visual stability

ability to perceive objects or our environment as stable even though our eyes are moving rapidly

Vestibular System provides...

Balance

Vestibular system location

located in inner ear

Vestibular organs

Three semicircular canals (anterior, posterior, and horizontal)

Sensitivity to changes

detect changes in acceleration, movements in different directions

Hair cells in vestibular system

transduce the mechanical movements into neural energy

Resting state

observed when stereocilia are not bent

Depolarization

observed when stereocilia bend in the direction of kinocilium

Hyperpolarization

observed when stereocilia bend in direction opposite to the kinocilium

Otolith Organs

sense linear acceleration and gravity

Utricle

contain hair cells that detect changes in acceleration along the horizontal plane

Saccule

Contain hair cells that detect changes in acceleration along the vertical plane

Otoconia

crystals lying on top of a gelatinous layer

Striola

band that determines the direction of the kinocilium

semicircular canals

sense rotational movements

Ampulla

each canal has one containing a cupula which is the gelatinous membrane

Cupula

the bottom part of this contains hair cells

Hair cells (Vestibular sense)

As the fluids move in the canals, they will push the cupula and the stereocilia will bend

Push- Pull effect

the arrangement of the hair cells within the two ears is such that when one ear is depolarized the other is hyper polarized

High amplitude movements

larger change in voltage than small amplitude movements

\-Sinusoidal changes in angular acceleration

Passive Translation

Perception of tilt

Vertigo and Vestibular Neuritis

off balance, dizzy, spinning, nausea

Labyrinthitis

inflammation of vestibular and cochlear nerve

Motion sickness

Effect when visual and/or motor feedback is inconsistent with vestibular info

Light

electromagnetic energy

Wavelength

distance between peaks

intensity

height of wave

frequency

number of waves per unit of time

photon

A particle of electromagnetic radiation with no mass that carries a quantum of energy

Properties of light

- scattered/diffracted

- Absorbed

- Reflected

- Transmitted

- Refracted

Reflected light enters eye through

pupil

light is focused on retina by

cornea and lens

Sclera

protective membrane

Cornea

clear surface; focuses light towards retina

Iris

eye color

Heterochromia

when person has irises of different colors

Pupullary reflex

automatic expansion and contract of pupils in different light circumstances