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AME: Adult Hearing Disability
Author: Timothy Lewis, M.D.
Competencies: Medical Knowledge, Patient Care
Learning Objectives: After reading this information you should be able to describe the aging auditory
system and mechanisms of hearing loss, counsel patients regarding hearing loss and noise exposure,
identify adults with hearing disability, communicate effectively with hearing impaired individuals, and
make effective referrals for audiology and otolaryngology services.
Presbycusis and the Aging Auditory System
The most common pattern of hearing loss in older adults is presbycusis, a bilateral high frequency
sensorineural hearing loss that occurs with advancing age. Pure- tone threshold sensitivity diminishes
with age; those under 55 years typically lose hearing at a rate of 3 dB per decade, and those over 55 at a
rate of 9 dB per decade.[1] Speech discrimination is also reduced with aging.
Major Types of Hearing Loss
Disorders of the outer and middle ear cause conductive hearing loss by disrupting sound transmission via
the external canal, tympanic membrane, and ossicular chain. Disorders of the inner ear cause
sensorineural hearing loss by damaging the cochlea, eighth cranial nerve, or internal auditory canal.
Mixed hearing loss involves conductive and sensorineural mechanisms.
Prevention of Noise-induced Hearing Loss
Noise-induced hearing loss is permanent but largely preventable. It begins at the higher frequencies
(3,000 to 6,000 Hz) and develops gradually as a consequence of cumulative exposure. Counsel patients
to take corrective action to protect hearing during activities that generate excessive noise exposure such as
lawn mowing (90 dB), stereo headphone use (100 dB), or firearm use (140 to 170 dB). Hearing loss can
develop following chronic exposures equal to an average decibel level of 85 dB or higher for an 8-hour
period.[2]
Hearing Disability Morbidity
Hearing disability is a prevalent condition posing significant disease burden. The prevalence of hearing
loss is estimated to double per decade, beginning with 16% at 60 years of age and proceeding to 32% at
70 years of age, and 64% at 80 years of age. The associated morbidities include diminished speech
understanding, social isolation, and depression. Hearing impairment can also mimic cognitive
dysfunction.
Screening for Hearing Impairment and Disability
Elicit history annually regarding difficulty hearing during challenging listening tasks such as conversing
in large groups or on the telephone. Obtain collateral history from a spouse or other individuals familiar
with the patient's hearing when feasible. Questionnaires are also useful in identifying persons with
hearing disability. The Hearing Handicap Inventory for the Elderly - Screening Version (HHIE-S) is a
quick, reliable, and valid self-assessment tool for identifying elderly persons with hearing disability (see
last page). The HHIE-S has a sensitivity of 76% and a specificity of 71% (for a cutoff score above eight)
when compared to pure-tone audiometry. Alternatively, a portable audiometer is another screening tool
that permits the identification of adults with hearing impairment. Using a 40 dB screening level, one such
device (Audioscope; Welch Allyn, Inc.) has a sensitivity ranging from 87% to 96%, and a specificity
ranging from 70% to 90%.[3] Screening tests such as the whispered voice, the finger rub, and the tuning
fork test have been studied with relatively few patients and examiners; inadequate data exists regarding
the interobserver reliability and observer repeatability for these tests.[4]
Communicating with Hearing Impaired Persons
Simple actions can facilitate communication with hearing impaired persons. These actions include
keeping the speaker’s face well lit and in full view of the listener (within 2 to 3 feet), reducing
background noise, and delivering speech with adequate pauses between sentences. Avoid shouting and
attempt to speak clearly at a slightly louder than normal intensity. When repetition is necessary, attempt
to paraphrase the message or write key words. Additionally, warn the listener when the subject of
conversation is about to change. When the above measures are inadequate, consider using a portable
amplifier device with headsets (i.e., a PocketTalker).
Audiology and Otolaryngology Referrals
Patients with hearing loss not amenable to medical or surgical treatment should be referred to a clinical
audiologist for aural rehabilitation services. The amount of hearing loss is less crucial than is patient
awareness and acceptance of hearing loss, communication difficulties, and motivation to try
amplification. The audiologist will recommend a type of hearing aid(s) based on the patient’s hearing
needs and goals, provide training in the use of amplification and other selected rehabilitative approaches,
review the advantages and limitations of hearing aids, and provide supportive follow-up during the trial
period and after the purchase. Primary care physicians should encourage new hearing aid users not to
abandon their devices prematurely since it usually takes over a month to adjust to amplification and
experience its full benefits.
Patients with hearing loss that appears possibly amenable to medical or surgical treatment should be
referred to an otolaryngologist (ENT). Hearing loss patterns that should prompt consideration for ENT
referral include: unexplained unilateral, sudden onset, loss associated with ear pain, tinnitus, or drainage,
or loss associated with middle ear diseases such as cholesteatoma or tympanic membrane perforation.
Causes of sudden hearing loss include viral cochleitis, vascular ischemic events, acoustic neuroma,
Ménière’s disease, multiple sclerosis, and perilymph fistulas. ENT referral is generally appropriate for
patients who have hearing loss that deviates from the pattern characteristic for presbycusis (bilateral,
symmetric, high frequency hearing loss). An example is Ménière’s disease that causes hearing loss that is
almost always low frequency and is typically episodic with periods of vertigo, hearing loss, tinnitus, and
aural fullness.
NOTE: we have a portable audiometer in Hoxworth – it is kept in the Medicine Pediatrics practice. To
use it, please contact XXXXXXXXXXXXXXXX
Hearing Handicap Inventory For the Elderly – Screening Version
Questions
No
Sometimes
Yes
Does a hearing problem cause you to feel
embarrassed when meeting new people?
0
2
4
Does a hearing problem cause you to feel
frustrated when talking to members of your
family?
0
2
4
Do you have difficulty hearing when someone
whispers?
0
2
4
Do you feel handicapped by a hearing problem?
0
2
4
0
2
4
0
2
4
Does a hearing problem cause you to have
arguments with family members?
0
2
4
Does a hearing problem cause you difficulty
when listening to TV or radio?
0
2
4
2
4
Does a hearing problem cause you difficulty
when visiting friends, relatives, or neighbors?
Does a hearing problem cause you to attend
religious services less often than you would
like?
Do you feel that your hearing limits or hampers
your personal or social life?
0
Does a hearing problem cause you difficulty
0
2
when in a restaurant with relatives or friends?
Total Score:_____________ (Ranges 0 to 40). Score >8 indicates hearing disability.
4
References:
1.
Jennings, C.R. and N.S. Jones, Presbyacusis. J Laryngol Otol, 2001. 115(3): p. 171-8.
2.
Rabinowitz, P.M., Noise-induced hearing loss. Am Fam Physician, 2000. 61(9): p. 2749-56,
2759-60.
3.
Lichtenstein, M.J., F.H. Bess, and S.A. Logan, Validation of screening tools for identifying
hearing-impaired elderly in primary care. Jama, 1988. 259(19): p. 2875-8.
4.
Mulrow, C.D. and M.J. Lichtenstein, Screening for hearing impairment in the elderly: rationale
and strategy. J Gen Intern Med, 1991. 6(3): p. 249-58.
5.
Weinstein, B.E., Geriatric Audiology. 2000, New York: Thieme Medical Publishers. 332.
6.
Mulrow, C.D., et al., Quality-of-life changes and hearing impairment. A randomized trial. Ann
Intern Med, 1990. 113(3): p. 188-94.
7.
Yueh, B., et al., Randomized trial of amplification strategies. Arch Otolaryngol Head Neck Surg,
2001. 127(10): p. 1197-204.
Discussion Questions:
True or False:
1. When hearing loss is identified by air conduction and bone conduction, a conductive hearing loss
is present.
2. When air-conduction results suggest hearing loss, but bone-conduction results are normal, a
conductive hearing loss is present.
Discussion: An audiogram measures hearing levels for air-conduction and bone conduction of pure tones
at specified frequencies in each ear. Air-conduction testing measures the function of the entire auditory
system from the ear canal through the middle ear to the cochlea and its afferent neural pathways to the
brain. Therefore, loss in air-conduction can be due to a disorder anywhere in the auditory system. To
better locate the anatomic site of the hearing disorder, pure-tone bone-conduction is also performed.
Sound transmitted via bone-conduction bypasses the outer and middle ear. When air and bone conduction
is impaired, sensorineural hearing loss is present. Therefore statement 1 is false, and 2 is true.
3. A jet air plane at take off generates about 150 dB of noise, whereas light traffic generates about
50 dB. Which is a true comparison of the sound intensities for these two events?
A. A jet plane’s sound intensity is 1 billion times louder than light traffic.
B. A jet plane’s sound intensity is 1000 times louder than light traffic.
C. A jet plane’s sound intensity is 100 times louder than light traffic.
D. A jet plane’s sound intensity is 3 times louder than light traffic.
Discussion: Because dB units comprise a logarithmic scale, 150 dB is actually 1 billion times louder than
50 dB.
4. For how many continuous hours would a person have to operate a lawn mower to require the
wearing of hearing protection by OSHA standards (1910.95)?
A. 2 hours
B. 4 hours
C. 6 hours
D. 8 hours
E. 10 hours
Discussion: A lawnmower generates about 90 dB. Hearing loss can develop following chronic
exposures equal to an average decibel level of 85 dB or higher for an 8-hour period.
5. Each of the following statements expresses a myth about hearing aids except:
A. Hearing aids restore hearing to normal.
B. Hearing aids eliminate all communication problems.
C. All hearing aid users can achieve adequate speech recognition with hearing aids alone.
D. Most people with hearing aids do not like how they sound.
E. Randomized controlled clinical trials have demonstrated significant improvements in
social and emotional function, communication function, and depression among hearing
aid recipients.
Discussion: A-D are all myths.[5] Hearing aids improve hearing but do not return it to normal, nor do
they eliminate all communication problems. Speech recognition sometimes requires more than a
hearing aid; for instance, a patient may have to learn lip reading techniques to augment
amplification. Growing evidence is showing that hearing aids improve quality of life among
adults with hearing impairment.[6, 7]