Download selection and evaluation

CSD 2230
HUMAN COMMUNICATION
DISORDERS
Audiology

The Profession

Acoustics

Anatomy

Hearing Loss and Pathologies

Assessment and Treatment
The Profession of Audiology
The discipline involved in:
The prevention, identification,
and evaluation of hearing
disorders
The selection and evaluation of
amplification systems
The habilitation/rehabilitation
of individuals with hearing
loss
What Kinds of Audiologists are
There?
Rehabilitative Audiologists
Educational Audiologists
Medical Audiologists
Industrial Audiologists
Audiologists in Private Practice
University-Based Audiologists
Why Are Audiologists Important??
Hearing loss interferes
with communication…
Adults
Consequences
Children
Consequences
Video
The Hearing System
The Hearing System
Basic schematic diagram of the entire auditory
system
The Outer Ear
Major Landmarks:
1.
2.
3.
Pinna
External Auditory
Meatus
Tympanic Membrane
Function of the Outer Ear
1.
2.
3.
Collect and funnel
sound to the
eardrum
Protection
Resonance
The Middle Ear
Major Landmarks:
Middle Ear Space
2. Eustachian Tube
3. Oval and Round
Windows
4. Ossicles
1.
Function of the Middle Ear
1.
2.
Amplifier
and
Transformer
Protection
The Inner Ear
Major Landmarks:
1. Bony Labyrinth
2. Cochlea
3. Auditory and
Vestibular Portions
4. Organ of Corti
5. Hair Cells
Central Auditory Pathways
Types of Hearing Impairment
A loss of sensitivity
Auditory nervous
system pathology
Important Terms

Time of onset
 Congenital
 Acquired
Adventitious
Important Terms
•







Time Course
Acute
Chronic
Sudden
Gradual
Temporary
Permanent
Progressive
Fluctuating
Important Terms
Number of Ears Involved
Unilateral
 Bilateral

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”
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
Mixed Hearing Loss
“A loss with both a conductive and
sensorineural component.”
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
Auditory Pathologies
Outer and middle ear disorders
 Conductive pathologies
Cochlear disorders
 Sensorineural pathologies
Central auditory disorders
 Central auditory pathologies
Outer and Middle Ear Disorders
Structural defects due to embryologic
malformations
Structural changes secondary to infection or
trauma
Microtia
“an abnormal
smallness of
the auricle”
Atresia
“the absence of
an opening of
the external
canal”
Outer Ear Disorders
Perforation of
the tympanic
membrane
Middle Ear Disorders
Otitis Media
Most common cause
of transient
conductive hearing
loss in children
Inflamation of the
middle ear
Caused by eustachian
tube failure
Otitis Media Facts
76-95% of all kids will have one episode of OM by age 6
Prevalence is highest during the first two years of life
50% of all kids with one episode before their first birthday will
have 6 or more bouts within two years
Most episodes occur in winter and spring
Risk factors
Cleft palate
Down syndrome
Native Americans
Urban poor
Day care
Secondhand smoke
Otosclerosis
n
“a bone disorder that
affects the stapes and the
bony labyrinth of the inner
ear. The disease process
is characterized by
resorption of bone and
new spongy formation
around the stapes and oval
window”
Otosclerosis

Facts:
 Hereditary
 Women are more
likely to develop the
disorder
 Usually bilateral
 Progressive
Cochlear Disorders
Syndromes and
inherited
disorders
Syndromic
disorders
Nonsyndromal
disorders
Types of Nonsyndromic
Disorders
Dominant
Dominant
progressive
Dominant
progressive
with adult
onset
Recessive
hereditary
SNHL
X-linked
Noise Induced Hearing Loss
n
The degree of SNHL
depends on
 The intensity of the noise
 The spectral composition
of the noise
 The duration of exposure
 Individual susceptibility
Infections
Congenital

Cytomegalovirus

HIV

Rubella

Syphilis

Toxoplasmosis
Infections
Acquired

Herpes
Zooster
Oticus
(Chicken Pox)

Mumps

Syphilis
Presbycusis
Loss of hearing that gradually
occurs in most individuals as
they grow old.
It is estimated that 40-50
percent of people 75 and older
have some degree of hearing
loss.
It involves a progressive loss of
hearing, beginning with highfrequency sounds such as
speech.
Presbycusis most often occurs in
both ears, affecting them
equally
Central Auditory Disorders
VIII Nerve tumors
Other diseases of the
VIII Nerve
Neural disorders
Cochlear neuritis
Diabetes mellitus
Brain Stem disorders
Infarcts
Gliomas
Multiple sclerosis
Temporal Lobe disorders
Hearing Assessment
Main questions
1.
2.
3.
Is hearing normal?
What is the degree
of hearing loss?
What type of
hearing loss is it?
Hearing Assessment Procedures
Behavioral Measures
Measures of hearing behavior dependent on
the perceptions and cooperation of the
listener
Nonbehavioral Measures
Acoustic or physiological responses recorded
in association with an acoustic event
Pure Tone Audiometry




Major behavioral auditory measure
Measurement of pure tone thresholds between 250-8000
Hz
Air conduction
Bone conduction
Pure Tone Audiometry
The results of PTA tell us
1.
2.
Air conduction
thresholds across
frequency tells us if
hearing is normal or
not
If hearing by air
conduction is NOT
normal, the thresholds
tell us the degree of
hearing loss
Pure Tone Audiometry
The results of PTA tell us
1.
2.
3.
If hearing is normal or not
the degree of hearing loss
Differences between hearing by air
conduction and hearing by bone conduction
tell us the type of hearing loss
Air Conduction vs Bone Conduction
Testing
Air conduction tests
the entire
auditory system.
Bone conduction
bypasses the
conductive
mechanism, so it
tests only the
inner ear.
The Audiogram
What the Audiogram Says About
the Impairment
Within normal limits
Mild
Moderate
Severe
Profound/deaf
Determining a Conductive
Hearing Loss
Determining a Sensorineural
Hearing Loss
Determining a Mixed Hearing
Loss
Speech Audiometry
Another behavioral
measure of auditory
ability
Speech thresholds
Speech Reception
threshold
Speech Awareness
threshold
Word recognition
testing
Identifying Hearing Loss
Through the First Year





Communication checklists
Parents’ reports
Case history
Informal observation
Formal testing


Visual Reinforcement Audiometry
Behavioral Observation Audiometry
Typical Response Levels to
Sounds from Birth-2 years
Nonbehavioral Measures of
Hearing
Auditory
brainstem
evoked
response
(ABER)
Nonbehavioral Measures of
Hearing
Otoacoustic
Emissions
Treatment
Medical
Most conductive hearing
losses, caused by
pathologies in the outer
and/or middle ear, can
be treated successfully
by medication and/or
surgery
Treatment
Amplification
Hearing aids are the most
common treatment of
sensorineural hearing
loss
Hearing aids amplify
speech and other
sounds
They work best for people
with mild through
severe degrees of
hearing loss
Treatment
Cochlear Implants
Used for children and
adults who are deaf
These devices stimulate
the auditory nerve
directly
They are best for people
who get very little
benefit from
conventional hearing
aids
Treatment
Habilitation/Rehabilitation
Auditory Training
Children and adults
Communication Strategies
Speechreading, noise management, assertiveness
training
Communication Methods
Sign language, cued speech
Counseling