topic 1 types of hearing impairment. types of hearing impairment a loss of sensitivity auditory...
Post on 21-Dec-2015
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TOPIC 1
TYPES OF HEARINGIMPAIRMENT
Types of Hearing Impairment
A loss of sensitivity
Auditory nervous system
pathology
Important Terms
Time of onset
Congenital: present at birth Acquired: obtained after
birth Adventitious: acquired after
birth
Important Terms
Time Course
Acute: sudden onset/short duration
Chronic: long duration Sudden: rapid onset Gradual: changes slowly over
time
Important Terms
Time Course
Temporary: limited duration Permanent: irreversible Progressive: advancing Fluctuating: changes in degree
over time
Important Terms
Number of Ears Involved
Unilateral: Just one
Bilateral: Both
Hearing Sensitivity Loss
“The ear is not as sensitive as normal in detecting sound”
Types:
Conductive Sensorineural Mixed
Conductive Hearing Loss
“Caused by an abnormal reduction or attenuation of sound as it travels from the outer ear to the cochlea”
Conductive Hearing Loss
An audiogram of a bilateral conductive hearing loss
Conductive Hearing Loss
Differences in the air-bone gap across different types of hearing loss
Sensorineural Hearing Loss
“Caused by a failure in the cochlea to transduce the sound from the middle ear to neural impulses in the VIII Nerve.”
Sensorineural Hearing Loss
n Implications include:
A reduction in the sensitivity of the receptor cells in the cochlea
A reduction in the frequency resolving power of the cochlea
A reduction in the dynamic range of the system
Sensorineural Hearing Loss
An audiogram of a bilateral sensorineural hearing loss
Sensorineural Hearing Loss
Differences in the air-bone gap across different types of hearing loss
Mixed Hearing Loss
“A loss with both a conductive and sensorineural component.”
Mixed Hearing Loss
An audiogram of a bilateral mixed hearing loss
Mixed Hearing Loss
Differences in the air-bone gap across different types of hearing loss
Types of Hearing Impairment
A loss of sensitivity
Auditory nervous system pathology
Auditory Nervous System Impairment
Causes:
Disease Disordered auditory nervous
system development
Auditory Nervous System Impairment
Kinds:
Retrocochlear disorders Central auditory processing
disorders
Auditory Nervous System Impairment
§ Auditory Characteristics:
Reduced ability to understand speech in a noise background
Problems understanding speech with reduced redundancy
Problems with localization and lateralization
Problems processing normal or altered temporal cues
