Exam 1 Comm. Disorders

A mechanical disturbance propagated through an elastic medium

displacing one object to another (D,T,K)

tends to want to maintain it's shape

number of cycles per second

sound deflects or bends around

reflects off objects

bends around objects

two or more sounds add together

reinforce one another and add together

two forces headed in opposite direction and sound is reduced

Natural frequencies at which objects oscillate. unique to each object

sum of oscillations. All complex sounds are a superposition ofoscillations

bending of sounds around objects

bouncing of sound off of objects

frequency analysis

pinna, ear canal

tympanic membrane, oval window, ossciles

cochlea

Sound localization, Directionally-dependent filter

Funnels sound to amplify important speech frequencies

Eardrum, contact airborne sound

Impedence match between air and cochlear fluid. Prevents sound from bouncing back out the ear

stapes contact with base of cochlea

prevents damage from the inner ear. Acoustic Reflex

Area differential between tympanic membrane and oval window focuses pressure on oval window. Prevents sound from bouncing back out the ear.

Resonant element of inner ear, place code

hair cells and supporting structures

creates shearing force across stereocillia of hair cells

electroacoustic transduction

conversion of mechanical disturbance in fluids of cochlea to change in electrical potential across hair cell body

electrical disturbance to flow

Basic structures of all nerve fibers

Fatty sheath of axon, electrical insulation

carry info from brain to ear

carry info from ear to brain

connection between nerve fibers

chemical substance released by nerve fibers that creates a graded electrical potential

5%

95%

80%

20%

Many to one arrangement (Nerve fibers to Inner hair cells)(Detection)

One to many arrangement (Afferent nerve fibers to Outer hair cells)(Identification)

Tonotopic Organization, Mapping of frequency to place along the basilar membrane preserved in central auditory nervous system

Lateral inhibition, ehances contrast

An auditory delay line which helps explain whether sound comes form left or right by localization through coincidence detection

When hair cells no longer synapse at a certain frequency reorganize very rapidly with other hair cells to allow to hear certain frequencies

No such thing as all or none threshold. 75% signal strength required for correct performance

Threshold for the signal in quiet. Best sensitivity (1.0 - 4.0khz) of pure tone. Consonants help distinguish the difference between each word

A little more or less than 1dB

neural networks designed to detect specific features of sound. Specialization for speech

a fraction of a percent change between 600-2000 Hz. Ex. 1000hz to 1002hz

Effects of phase only audible through interference. Can either create sound or cancel sound.

Only energy within a critical band of frequencies surrounding the signal are effective in masking the signal

250 noise bandwidth - point of which there is no further masking

For wavelengths greater than the diameter of the head (f<2000hz),the primary cue is ITD. which ever ear it reaches first

For wavelengths < than the diameter of the head (f>2000hz), the primary cue is IID. Sound reflects and sound shadow is produced.

Threshold change in angle for a change in sound source position (1degree)

2000Hz

first arriving wavefront dominates perceived location (auditory illusion)

Improved audibility in dichotic listening. Loud party

Exposure to intense sound or to moderately intense sounds over long periods of time

Hearing loss due to the aging process

90%

shearing force subjects delicate stereocillia to potential damage

Higher hz have much higher threshold to hear. First thing that goes are high frequencies

don't hear small wavelenghts, loss of OHC's results in abnormal growth of loudness

loss of OHC's results in loss of frequency selectivity. frequencies become blurred together

1 in 22 births

purpose is to identify those who may have a hearing loss

Purpose is to determine degree, shape, type, and possible site of hearing loss; also to determine possible cause and treatment

problem in outer or middle ear

problem in cochlea, auditory nerve or central auditory nervous system

both conductive and sensorineural

from client reports and medical records

check for outer each occlusion

a measure of eardrum and middle ear function

pure tone thresholds, air and bone conduction

ability to understand speech at intensity levels well above the threshold of hearing

Conductive hearing loss, other and middle ear

sensorineural hearing loss inner ear and cochlea

conductive

sensorineural

infection of the middle ear, most common cause of conductive hearing loss in childeren (conductive)

fixation of the stapes, most common cause of conductive hearing loss in adults

abnormal volume of fluid within the inner ear (sensorineural)

hearing loss due to aging, most common overall (sensorineural)

Low level acoustic signals of cochlear origin that may be recorded in the closed ear canal. Hearing screening in newborns

rocking motion of OHC's causes basilar membrane to vibrate, produces sound that travels out the ear canal. Hair cells functioning properly

The ABR is a waveform that is formed by the synchronous electric activity of neurons in various parts of the auditory brainstem. They are typically elicited by acoustic signals that trigger a neural response, but they do not imply hearing. People who don't have behavioral responses

Abnormal amplitude and latency indication of hearing loss

Tumor on Auditory Nerve

a hearing disorder in which sound enters the inner ear
normally but the transmission of signals from the inner ear
to the brain is impaired (Physiological).

an inability to differentiate, recognize, or understand
sounds when hearing and intelligence are normal
(Psychological).

A rapid loss of hearing occurring over a period of 3 days or less.

Hearing trumpets, early electronic hearing aids, transistorized hearing aids, Digital hearing aid, in ear hearing aids

microphone to circuit to reciever to ear canal and powered by battery

Transducer vibrates ossicular chain

150,000 people worldwide. Coded signals to transducer which vibrates sclap to electrodes to auditory nerve to brain

attempt to provide spatial info

electrode stimulation of auditory brainstem

acoustic stimulation of cochlear through bone conduction

incomplete development of the cochlea

abnormal skin growth (tumor) in middle ear

detached bones of the ossicular chain

(small ear) congenital deformity of the pinna

(no ear) absence of the pinna

absence of the ear canal

tumor on auditory nerve complex

startle response to loud sounds, increase sucking in response to sound

turns head in search of sound, reaches with hands

mobile, doesnt sit still

talks and understand simple intstructions, plays games/computers, likes to please adults

conditioned head turn response