Download Hearing and Vision Impairment

HEARING
IMPAIRMENT
OBJECTIVES
Know and understand:
• The mechanisms of normal hearing
• The common causes of hearing loss
• Management and treatment options for
hearing loss
• Strategies to improve communication with
adults with hearing loss
Slide 2
TOPICS COVERED
• Normal Hearing
• Age-related Changes That Can Affect Hearing
• Causes and Types of Hearing Loss
• Presbycusis
• Diagnosing and Treating Hearing Loss
• Strategies to Enhance Communication with
Hearing-impaired Persons
Slide 3
THE IMPACT OF HEARING LOSS
• The 4th most common chronic disease among
older adults
• Often considered benign, but profoundly affects
quality of life
• May contribute to family discord, social isolation,
loss of self-esteem, anger, depression
• Treatment can improve quality of life by
facilitating interaction with family, friends, and
caregivers
Slide 4
NORMAL HEARING
• Sound energy is transmitted through the external ear
to the tympanic membrane and auditory ossicles
• Malleus, incus, and stapes transmit vibrations to the
oval window of the cochlea
• Fluid waves stimulate hair cells and generate sensory
potential
• An excitatory postsynaptic potential is generated
• When threshold is reached, impulses are sent via
cochlear neurons to the cochlear nuclei and then to
auditory pathways in the brain
Slide 5
AGE-RELATED CHANGES THAT CAN
INTERFERE WITH HEARING
• External ear canal: Walls thin
• Cerumen: Becomes drier & more tenacious, increasing
likelihood of impaction
• Eardrum: Thickens, appears duller
• Cochlea: Hair cells are lost, basilar membrane stiffens,
auditory structures calcify, cochlear neurons are lost
• Stria vascularis: Capillaries thicken, endolymph production
decreases, Na+ K+ ATPase activity decreases
Slide 6
PREVALENCE OF HEARING LOSS
% of population
30
25
20
15
10
5
0
Age 65-75
Age >75
50%–100% of nursing home residents have hearing loss
Slide 7
CAUSES AND TYPES OF HEARING LOSS
• May be caused by pathology in:





External ear canal
Middle ear
Auditory nerve
Central auditory pathways
A combination
• Categories of hearing loss based on cause:
 Conductive
 Sensorineural
 Mixed
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SPEECH RANGE ON THE AUDIOGRAM
10
20
30
40
Vowel sounds
50
60
8000
4000
2000
1000
500
70
250
Loudness (decibels)
0
Frequency (Hz)
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CONDUCTIVE HEARING LOSS (1 of 2)
• External ear pathology
 Ceruminosis
 Foreign body
• Middle-ear pathology




Otosclerosis
Cholesteatoma
Tympanic membrane perforation
Middle ear effusion
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CONDUCTIVE HEARING LOSS (2 of 2)
0
10
20
30
40
50
60
70
80
90
100
Bone conduction,
R
Bone conduction,
L
Air conduction, L
Frequency (Hz)
8000
4000
2000
1000
500
Air conduction, R
250
Loudness (decibels)
Air conduction thresholds are greater than bone conduction thresholds,
most likely due to middle ear pathology
Slide 11
SENSORINEURAL
HEARING LOSS (1 of 2)
• Most often from age, noise damage, or ototoxicity
• Cochlear disease
 Most common cause, most often from noise damage
• Other causes:






Ototoxic medications
Genotype
Vascular disease
Occupational and environmental chemical exposures
Autoimmune disease
Auditory nerve tumors
Slide 12
SENSORINEURAL
HEARING LOSS (2 of 2)
Air and bone conduction thresholds are the same, most likely due to inner
ear damage. The high-frequency pattern of this patient’s hearing loss is
typical for presbycusis.
Slide 13
PRESBYCUSIS
• Sensorineural hearing loss, usually symmetrical;
may have central components
• Classified by cochlear pathology:





Sensory
Neural
Strial
Cochlear conductive
Combined or indeterminate
• Amplification often helps
Slide 14
TYPES OF PRESBYCUSIS (1 of 3)
• Sensory presbycusis
 Loss of sensory hair cells in basal end of cochlea
 Slowly progressive loss, beginning with higher
frequencies
 Difficulty hearing in presence of background noise
 Steeply sloping audiogram
 Treatment: amplification
Slide 15
TYPES OF PRESBYCUSIS (2 of 3)
• Strial presbycusis
 A metabolic form of hearing loss
 Cochlear dysfunction, with atrophy of 30% or
more of the stria vascularis
 Onset in 20s to 60s
 Mild to moderate hearing loss in most frequencies
 Usually good speech discrimination
 Treatment: amplification
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TYPES OF PRESBYCUSIS (3 of 3)
• Neural presbycusis
 Cochlear neuronal loss of 50% or more
 Poor speech discrimination
 Amplification success is difficult
• Cochlear conductive presbycusis
 Changes in stiffness or mass; spiral ligament atrophy
 Audiogram descends gradually over 5 octaves
 Speech discrimination impaired
Slide 17
DIAGNOSIS OF HEARING LOSS
• Many older adults are unaware of their
hearing deficit
• Hearing loss can be interpreted as cognitive
impairment
• Tinnitus can be an early sign of hearing loss
Slide 18
MIXED HEARING LOSS
Bone conduction, L
Air conduction, R
0
10
20
30
40
50
60
70
80
90
100
Air and bone conduction
thresholds are abnormal,
with the greatest difference
seen for the left ear
8000
4000
2000
1000
500
This patient has pathology
in both the middle and
inner ears
250
Loudness (decibels)
Bone conduction, R
Air conduction, L
Bone conduction
thresholds for the left ear
are measured by masking
the right ear
Frequency (Hz)
Slide 19
DIAGNOSIS OF HEARING LOSS
IN PRIMARY CARE
• Otoscope: Exclude and treat cerumen impaction
• Audioscope: Screens for hearing loss at selected
frequencies (0.5, 1, 2, and 4 KHz) and at 2 loudness
levels (25 and 40 dB HL)
• Screening questionnaire, eg:
 Hearing Handicap Inventory for the Elderly
 Brief Hearing Loss Screener
Slide 20
WHEN TO REFER TO
OTOLARYNGOLOGIST
•
Asymmetrical hearing loss, which may indicate
tumor of posterior pharynx blocking eustachian
tube, or auditory nerve tumor
•
Cerumen impaction not responsive to
cerumenolytics, irrigation or manual extraction
•
History of tympanic membrane surgery or
perforation
Slide 21
WHEN TO REFER TO AUDIOLOGIST
 Consult to determine the presence and type of
hearing loss, recommend and fit hearing aids,
and provide auditory rehabilitation
 Assessment includes evaluation of pure-tone
thresholds for both air and bone conduction,
speech-recognition thresholds, speech
discrimination, and middle-ear function
Slide 22
TREATMENT OF HEARING LOSS
• Medical or surgical
• Hearing aids
• Assistive listening devices
• Cochlear implants
• Communication strategies
Slide 23
MEDICAL OR SURGICAL
Medical
• Paget’s disease, otosclerosis:
bisphosphonates
• Sudden hearing loss: corticosteroids or
immunosuppressants
Surgical
• Otosclerosis
• Tympanosclerosis
Slide 24
HEARING AIDS
• Two are better than one
• Not everyone benefits, ie, those with:
 Central auditory processing problems
 Poor speech discrimination
 Dementia
• Types:
 Analog (less expensive)
 Digital (smaller, customizable)
 Bone conduction (all-in-one headpiece or body aid)
• Many available styles
Slide 25
EFFECTS AND REHABILITATION OF
HEARING LOSS (1 of 3)
Degree
of Loss
Loss
in db
HL
Sounds
Difficult
to Hear
Mild
25 to Whisper
40
Effect on
Communication
Amplification or
Other Assistance
Needed
Difficulty underHearing aid
standing soft
needed in specific
speech or normal
situations
speech in presence
of background
noise
Slide 26
EFFECTS AND REHABILITATION OF
HEARING LOSS (2 of 3)
Degree of Loss
Loss
in db
HL
Sounds
Difficult to
Hear
Effect on
Communication
Amplification
or Other
Assistance
Needed
Moderate
41 to
55
Conversational
speech
Difficulty understanding any but
loud speech
Frequent need
for hearing aid
Severe
56 to
80
Shouting,
vacuum
cleaner
Can understand
only amplified
speech
Amplification
needed for all
communication
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EFFECTS AND REHABILITATION OF
HEARING LOSS (3 of 3)
Degree of
Loss
Loss
in db
HL
Sounds
Difficult
to Hear
Effect on
Communication
Amplification or
Other
Assistance
Needed
Profound
≥81
Hair dryer,
heavy
traffic,
telephone
ringer
Difficulty even with
amplified speech;
may miss
telephone calls
May need to
supplement
hearing aid with
lip-reading,
assistive listening
devices, sign
language
Slide 28
STYLES OF HEARING AIDS
• Completely in the canal
• Canal
• In the ear
• Behind the ear
• Body aid
• Bone conduction
Slide 29
COMPLETELY-IN-THE-CANAL
HEARING AIDS
• Degree of hearing loss: Mild to moderate
• Advantages
 Almost invisible
 Less occlusion of pinna  more natural sound
 Easier to use with headphones, telephone
• Disadvantages




User’s dexterity may be a problem
Small size may limit available features
May cost more than canal or in-the-ear aids
Shorter battery life
Slide 30
CANAL HEARING AIDS
• Degree of hearing loss: Mild to moderate
• Advantages
 More cosmetically appealing than larger aids
 Telecoil available in some models
 May be able to use with headphones
• Disadvantages
 User’s dexterity may be a problem
 Small size may limit available features
Slide 31
IN-THE-EAR HEARING AIDS
• Degree of hearing loss: Mild to severe
• Advantages




Ease of handling
Comfortable fit
Options: telecoil, directional microphone
More power than completely-in-the-canal or
canal aids
• Disadvantages
 More conspicuous than completely-in-the-canal
or canal aids
 May be difficult to use with headphones
Slide 32
BEHIND-THE-EAR HEARING AIDS
• Degree of hearing loss: Mild to profound
• Advantages
 Greatest power
 Options: telecoil, directional microphone, direct
audio input
 Earmold can be changed separately
• Disadvantages
 More conspicuous
 May be more difficult to insert than in-the-ear aids
 Difficult to use with headphones
Slide 33
BODY HEARING AIDS
• Degree of hearing loss: Severe to profound
• Advantages
 Greatest separation of microphone from receiver
reduces feedback
• Disadvantages
 Most conspicuous
 Picks up noise from rubbing on clothing
 Microphone is at chest or on waist but speech is
directed at ear level
Slide 34
BONE CONDUCTION AIDS
• Degree of hearing loss: mild to severe
• Advantages
 Bypasses middle ear
 Used if ear canal is unable to tolerate aid or
earmold
Slide 35
ASSISTIVE LISTENING DEVICES
• Pocket-sized, personal amplifiers
• Transmitter-receiver systems (FM, induction loop,
infrared)
• Telephone equipment: amplifiers, vibrating and
flashing ringer alert devices, text telephones
(TTY)
• Television listening devices
• Vibrating and flashing devices for alarm clocks,
Slide 36
smoke alarms, doorbells, and motion sensors
COST OF HEARING AIDS AND
ASSISTIVE LISTENING DEVICES (1 of 2)
Type of Technology
Cost
Assistive listening
devices
$150
to
$200
Comments
Useful for specific situations
Analog hearing aids
$1000 Smaller aids are more expensive
to
$1,100
Analog programmable
hearing aids
$1,150 Smaller aids are more expensive
to
$1,600
Digital, low end hearing
aids
$1,200 Similar to analog aid, but with
to
better sound quality
$2,000
Slide 37
COST OF HEARING AIDS AND
ASSISTIVE LISTENING DEVICES (2 of 2)
Type of Technology
Digital, mid-range
hearing aid
Cost
Comments
$1,800 Some sound processing included,
to
eg, a second program, feedback
$2,500 control, telecoil
Digital, premium hearing $2,500 Multiple features available, eg,
aid
to
background noise suppression,
$3,000 feedback management, multiple
programs, telecoil
Bone conduction
hearing aid
$400
to
$900
Available as all-in-one headpiece
or as body aid; used only if in-theear aid or earmold is not tolerated
NOTE: Assistive listening devices and hearing aids
are not covered by Medicare
Slide 38
COCHLEAR IMPLANT
• Electronic device that bypasses the function of
damaged or absent cochlear hair cells by providing
electrical stimulation to cochlear nerve fibers
• Implantation requires extensive pre-implant testing,
post-implant training, and general anesthesia
• Costs are partially covered by most Medicare carriers
and insurance companies; may require authorization
• Outcomes for adults >65 years are comparable to
those of younger adults, with excellent audiologic and
quality-of-life measures
Slide 39
STRATEGIES TO IMPROVE
COMMUNICATION (1 of 2)
• Obtain the listener’s attention before speaking
• Eliminate background noise as much as possible
• Be sure the listener can see the speaker’s lips:
 Speak face-to-face in the same room
 Do not obscure the lips with hands, mustaches,
or other objects
 Make certain light shines directly on the
speaker’s face, not from behind the speaker
Slide 40
STRATEGIES TO IMPROVE
COMMUNICATION (2 of 2)
• Speak slowly and clearly, but avoid shouting
• Speak toward the better ear, if applicable
• Change phrasing if the listener does not understand
at first
• Spell words out, use gestures, or write them down
• Have the listener repeat back what he or she heard
• Ask the listener the best way to communicate with
him or her
Slide 41
SUMMARY
• Hearing loss occurs commonly among older
adults and may lead to reduced quality of life,
high medical care costs, and loss of
independence
• Primary care providers should routinely screen
older adults for hearing loss
• Treatment options are available for many types
of hearing loss
Slide 42
CASE 1 (1 of 3)
• A 79-year-old man comes to the office because
he has increasing difficulty understanding
conversations with his grandchildren.
Slide 43
CASE 1 (2 of 3)
Which of the following is the most likely diagnosis?
A. Presbycusis
B. Sociocusis
C. Ototoxicity
D. Acoustic neuroma
Slide 44
CASE 1 (3 of 3)
Which of the following is the most likely diagnosis?
A. Presbycusis
B. Sociocusis
C. Ototoxicity
D. Acoustic neuroma
Slide 45
CASE 2 (1 of 3)
• A 75-year-old woman comes to the office
because she perceives hearing loss.
• On examination, both of her ears are impacted
with cerumen.
Slide 46
CASE 2 (2 of 3)
Which of the following types of hearing loss results
from impacted cerumen?
A. Conductive
B. Sensorineural
C. Mixed
D. Functional
Slide 47
CASE 2 (3 of 3)
Which of the following types of hearing loss results
from impacted cerumen?
A. Conductive
B. Sensorineural
C. Mixed
D. Functional
Slide 48
CASE 3 (1 of 4)
• A 75-year-old man presents for a routine exam.
• He states that recently he has had considerable difficulty
understanding speech, even when the speaker’s face is
within 6 feet of his own.
• He wears hearing aids because he has had sensorineural
hearing loss for many years, previously described by his
audiologist as severe, high-frequency, bilateral symmetric
loss.
• He has cut back on social engagements because the
hearing aids no longer help.
Slide 49
CASE 3 (2 of 4)
• His score on the Mini–Mental State Examination is 5
points lower than it was last year.
• His score on the Hearing Handicap Inventory for the
Elderly is now 28, increased from 20 last year.
• He is referred to his audiologist, who finds that the
patient’s hearing has declined to the level of profound
hearing loss and that speech comprehension is consistent
with the severity of hearing loss.
Slide 50
CASE 3 (3 of 4)
Which of the following is the most appropriate
recommendation for this patient?
A. Cochlear implant
B. Inteo hearing aid
C. Bone-anchored hearing aid
D. Auditory brain-stem implant
Slide 51
CASE 3 (4 of 4)
Which of the following is the most appropriate
recommendation for this patient?
A. Cochlear implant
B. Inteo hearing aid
C. Bone-anchored hearing aid
D. Auditory brain-stem implant
Slide 52
ACKNOWLEDGMENTS
Editor:
Annette Medina-Walpole, MD
GRS7 Chapter Author:
Priscilla Faith Bade, MD, MS
GRS7 Question Writer:
Barbara E. Weinstein, PhD
Pharmacotherapy Editor:
Judith L. Beizer, PharmD
Medical Writers:
Beverly A. Caley
Faith Reidenbach
Managing Editor:
Andrea N. Sherman, MS
Copyright © 2010 American Geriatrics Society
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