Download HEARING LOSS CONDUCTIVE HEARING LOSS

HEARING LOSS
CONDUCTIVE HEARING LOSS
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A conductive hearing loss is due to any
dysfunction of the outer and/or middle
ear.
ear
It may be congenital or acquired, and it
if left untreated it may result in a
reduction of hearing at all frequencies
on the audiometer.
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SYMPTOMS OF A
CONDUCTIVE HEARING LOSS
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Student may speak in a relatively soft
voice
Ability to understand speech is relatively
unimpaired if made loud enough
Tends to have the same degree of
hearing loss for all frequencies
May complain of tinnitus, a roaring,
buzzing or ringing sound
ETIOLOGY OF A CONDUCTIVE
HEARING LOSS
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Excessive accumulation of cerumen in
the external auditory canal
Foreign objects in the external auditory
canal
Inflammation, infection of the middle
ear (otitis media being the most
common cause)
ETIOLOGY OF A CONDUCTIVE
HEARING LOSS – Cont.
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Retraction, distention, puncture or
rupture of the tympanic membrane
Congenital
g
malformation of the outer
and/or middle ear
Otosclerosis, a disease affecting the
stapes ossicle of the middle ear
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Normally hard bone turns into a spongy
mass usually over the stapedial footplate
(usually has onset from mid-childhood to
late middle adult life)
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TREATMENT OF A
CONDUCTIVE HEARING LOSS
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Medical treatment can usually cure or
relieve these symptoms
Surgical intervention may be necessary
SENSORINEURAL HEARING
LOSS
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A sensorineural hearing loss is due to an
impairment of the inner ear, with an intact
outer and middle ear.
Occurs when sound cannot be perceived or
analyzed properly resulting from an
abnormality of the hair cells in the cochlea or
the nerve pathways from the inner ear to the
brain.
SENSORINEURAL HEARING
LOSS – Cont.
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This type of hearing loss usually results in
severe inability to hear at all frequencies, but
not always. Any loss greater than 60 dB HL
will
ill have
h
some degree
d
off sensorineural
i
l loss.
l
High pitched sounds are often affected which
makes it difficult for speech to be understood.
This is true of high frequency consonant.
Loudness has nothing to do with this inability
to hear.
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SYMPTOMS OF A
SENSORINEURAL HEARING LOSS
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May speak excessively loud
Generally has some trouble understanding
speech
T i ll has
Typically,
h better
b
hearing
h i in
i the
h low
l
frequencies
Speech sounds are distorted
Often a greater intolerance or discomfort for
loud sounds than a normally hearing student
May experience tinnitus, a roaring, buzzing or
ringing sound
ETIOLOGY OF A
SENSORINEURAL HEARING LOSS
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Congenital:
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damage to the developing embryo caused by
disease or drugs
A
Acquired:
i d
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anoxia at birth
disease, injury, toxic effects of drugs, fever
head injury
exposure to intense noise
vascular disturbances
Meniere’s Disease (fluids in the inner ear are
affected causing hearing loss and dizziness)
TREATMENT OF
SENSORINEURAL HEARING LOSS
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Usually cannot be remedied by medical
intervention
Neural implants, acupuncture, “miracle cures”
have no documented, scientific evidence of
effect
ff t on sensorineural
i
lh
hearing
i loss
l
Losses from vascular dysfunction are
sometimes treatable
May profit from:
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Hearing aids and/or auditory trainers
Speechreading and auditory training
Sign language
Cued speech
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MIXED HEARING LOSS
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A mixed hearing impairment is a
hearing loss involving both conductive
p
and sensorineural impairment
The outer, middle and inner ear may be
affected resulting from any one, or a
combination, of the causes listed for
conductive and sensorineural losses
Likewise, a combination of the
symptoms are exhibited.
TREATMENT OF A MIXED
HEARING LOSS
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The conductive component may be
correctable by surgery or medication
If such intervention is successful,
hearing will be improved by no more
than the amount of loss attributed to
the conductive component
GLOSSARY
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External ear: The portion of the ear consisting of
the auricle or pinna, external auditory canal, ending
at the tympanic membrane.
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Middle ear: An air filled cavity between the outer
and inner ear that includes the tympanic membrane,
the ossicles and the opening to the Eustachian tube.
Inner ear: That portion of the ear that includes the
cochlea an the semi-circular canals. These structures
are responsible for the sense of hearing, balance,
motion, etc.
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GLOSSARY – Cont.
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Auricle: the external portion of the ear; also called
the pinna.
External Auditory Canal: The passageway for
sound from the auricle to the tympanic membrane. In
adults, it is approximately 1- 1 ½ incles long.
Tympanic Membrane: Called the eardrum, it is a
membrane that separates the outer and middle ears.
It moves as a results of sound waves striking it and
sets the ossicles in motion.
GLOSSARY – Cont.
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Ossicles: The three small bones of the middle ear:
the malleus, incus, and stapes. They transmit sound
vibration
ib ation from
f om the tympanic
t mpanic membrane
memb ane to the
cochlea.
Stapedius muscle: One of the small muscles in the
middle ear. Contraction of this muscle in response to
a loud sound is an important part of impedence
testing.
GLOSSARY – Cont.
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Eustachian tube: A bony cartilaginous tube
connecting the middle ear with the back of the
pp y air to the middle ear
throat. It functions to supply
and to equalize pressure on both sides of the
tympanic membrane.
Cochlea: The inner ear structure that contains the
end-organ of hearing.
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GLOSSARY – Cont.
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Conductive hearing loss: Impairment of hearing
due to the interference of sound transmission to the
inner ear, usually occurring in the outer or middle
ear.
Sensorineural hearing loss: Impairment of
hearing caused by damage to the sensory
mechanism of the inner ear.
Mixed hearing loss: hearing loss resulting from
impairment of a combination of conductive and
sensorineural mechanism
GLOSSARY – Cont.
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Cerumen: Earwax secreted by wax-producing
glands in the external auditory canal
Otitis Media: Inflammation of the middle ear. If a
thin, watery fluid accumulates it is sometimes known
as serous otitus media.
Pure Tone testing: A method of hearing screening
utilizing puretones of various frequencies and
intensities.
GLOSSARY – Cont.
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Impedance Testing: An objective method of
testing
g the integrity
g y and function of the middle ear
system (Tympanometry).
Compliance: Relates to the mobility of a system; in
this instance, the middle ear. It is the inverse of
stiffness.
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DEGREES OF HEARING LOSS
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Normal hearing; 0-15 dB HL
Slight; 16-25 dB HL
Mild; 26 – 40 dB HL
Moderate; 41-55 dB HL
Moderately Severe; 56-70 dB HL
Severe; 71-90 dB HL
Profound; <91
What is an Audiogram?
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An audiogram is a
graphic
representation
p
of
one’s hearing
thresholds
Thresholds are the
softest sounds one
can hear at a
specific frequency
(pitch)
Frequencies of an Audiogram
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Frequencies or
pitches are graphed
from left to right
low pitches are on
the left
high pitches are on
the right
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Hearing Levels on an
Audiogram
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loudness is
graphed from top
to bottom in
H i Level
Hearing
L
l (dB)
soft sounds are at
the top
medium sounds
are in the middle
loud sounds are at
the bottom
Symbols on an Audiogram
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X’s represent the
softest sound one’s
left ear hears
through the air at a
certain frequency
O’s represent the
softest sound one’s
right ear hears
through the air at a
certain frequency
Symbols – Cont.
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We also see other
symbols on the
audiogram
< and >
>‘ss represent the
softest sound heard
through one’s mastoid
bone (bone behind your
ear)
[ and ]’s represent
one’s bone conduction
thresholds with masking
noise in the opposite
ear
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SLIGHT and MILD HEARING
LOSS
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Difficulty hearing faint or distant speech
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Needs favorable seating
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May benefit from speechreading instruction
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May benefit from hearing aid
MODERATE and MODERATELYSEVERE HEARING LOSS
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Conversational speech is just audible at a
distance of 3-5 feet
Use of hearing aid,
aid auditory trainer,
trainer
speechreading, favorable seating
Speech-language therapy to aid the student
in the communication skills
A student with this degree of hearing loss
usually requires special education services
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SEVERE HEARING LOSS
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May hear a loud voice about one foot from
the ear
With use of hearing
g aid and other listening
g
devices may recognize some speech and
detect environmental sounds
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Speech-language therapy to aid the student
in the communication skills
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A student with this degree of loss also
requires special education services
PROFOUND HEARING LOSS
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May not be able to detect the presence of even very
loud sounds (jet plane, subway, etc) without
amplification
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May perceive sound as vibrations
Does not rely on hearing as the primary channel for
communication
Use of amplification, plus all of the previously
mentioned services are needed, but may be less
successful in producing adequate oral speech and
language
Special education services are required
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