Types
of Hearing Loss
· Sensorineural
hearing loss (or nerve-related deafness) involves damage
to the inner ear caused by aging, pre-natal and birth-related problems, viral
and bacterial infections, heredity, trauma, exposure to loud noise, fluid
backup, or a benign tumor in the inner ear. Almost all sensorineural hearing
loss can be effectively treated with hearing aids.
· Conductive hearing loss
involves the outer and middle ear that may be caused by blockage of wax, punctured
eardrum, birth defects, ear infection, or heredity, and often can be effectively
treated medically or surgically.
· Mixed hearing loss
refers to a combination of conductive and sensorineural loss and means that
a problem occurs in both the outer or middle and the inner ear.
· Central hearing loss
results from damage or impairment to the nerves or nuclei of the central nervous
system, either in the pathways to the brain or in the brain itself.
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Facts
on Hearing Loss in Adults
· One in every ten (28 million) Americans has
hearing loss. As baby boomers reach retirement age starting in 2010, this
number is expected to rapidly climb and nearly double by the year 2030.
· The prevalence of hearing loss increases with
age, up to 1 in 3 over age 65. Most hearing losses develop over a period of
25 to 30 years.
· Among seniors, hearing loss is the third most
prevalent, but treatable disabling condition, behind arthritis and hypertension.
· The vast majority of Americans (95%) with
hearing loss can treat their hearing loss with hearing aids. Only 5% of hearing
loss in adults can be improved through medical or surgical treatment.
|
Click logos for more information from the
National Hearing Loss Association of America
and the
Hearing Loss Association of Michigan
|
1 National Center
on Hearing Assessment and Management. http://www.infanthearing.org/research/summary/prevalence.html.
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Facts
on Hearing Loss in Children
· Everyday in the United States, approximately
1 in 1,000 newborns (or 33 babies every day) is born profoundly deaf with
another 2-3 out of 1,000 babies born with partial hearing loss, making hearing
loss the number one birth defect in America. 1 2
· Newborn hearing loss is 20 times more prevalent
than phenylketonuria (PKU), a condition for which all newborns are currently
screened. 3
· Of the 12,000 babies in the United States
born annually with some form of hearing loss, only half exhibit a risk factor
– meaning that if only high-risk infants are screened, half of the infants
with some form of hearing loss will not be tested and identified. 4
In actual implementation, risk-based newborn hearing screening programs identify
only 10-20% of infants with hearing loss. 5 When hearing
loss is detected beyond the first few months of life, the most critical time
for stimulating the auditory pathways to hearing centers of the brain is lost,
significantly delaying speech and language development.
· Only 69% of babies are now screened for hearing
loss before 1 month of age (up from only 22% in 1998). Of the babies screened,
only 56% who needed diagnostic evaluations actually receive them by 3 months
of age. Moreover, only 53% of those diagnosed with hearing loss are enrolled
in early intervention programs by 6 months of age. 6 As a result, these children tend to later re-emerge in our schools’ special education (IDEA, Part B) programs.
· When children are not identified and do not
receive early intervention, special education for a child with hearing loss
costs schools an additional $420,000, and has a lifetime cost of approximately
$1 million per individual. 7
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Early
Hearing Detection & Intervention (EHDI) Recommendations
· The Joint Committee on Infant Hearing 8 and U.S. Public Health Service’s Healthy People 2010 health objectives 9 recommend that all newborns be screened for hearing
loss by 1 month of age, have diagnostic follow-up by 3 months, and receive
appropriate intervention services by 6 months of age.
· A National Institutes of Health (NIH) Consensus
Panel in 1993 recommended hearing screening of all newborns. The consensus
report concluded that the best opportunity for achieving this goal is provided
by the development of hearing screening programs for newborns in hospital
nurseries or in birthing centers, prior to discharge. 10
· The U.S. Preventive Services Task Force in
2001 concluded that universal newborn hearing screening does lead to earlier
identification and treatment. However, there were not enough clinical studies
of sufficient size and strength to evaluate long-term outcomes. While the
preponderance of anecdotal evidence and clinical research indicates that EHDI
provides substantial benefit, additional clinical outcome studies and clinical
trials are needed. 11
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Methods
and Costs for Newborn Hearing Screening
· Advances in technology for newborn hearing
screening at most birthing hospitals have allowed for cost containment, with
current charges ranging from $25 to $60. The cost of identifying a newborn
with hearing loss is less than one-tenth the cost of identifying newborns
with PKU, hypothyroidism, or sickle cell anemia, which are screened for in
nearly every state. 12
· Two types of electrophysiologic procedures
are used to screen newborns singly or in combination:
Auditory brainstem responses (ABR) are measured by
placing sensors on the baby’s head. Sound is then introduced to the
baby’s ears through tiny earphones while the child sleeps. A computer
allows brainwave activity to be recorded to indicate whether the ear and auditory
brainstem pathway are responding to sound. This test is painless and takes
only about 5 minutes.
Otoacoustic emissions (OAE) are faint
sounds produced by most normal inner ears. The sounds cannot be heard by people,
but can be detected by very sensitive microphones that are placed in the ear
canal. During testing, a tiny flexible plug is inserted into the baby’s
ear and sound is then projected into the ear through the plug. A microphone
inside the plug records the otoacoustic emissions that the normal ear produces
in response to the incoming sound. Testing is also painless, takes about 5
minutes to complete, and can be done while the baby sleeps.
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Benefits
of Early Hearing Detection and Intervention (EHDI)
· Infants identified with hearing loss can be
fit with amplification by as young as 4 weeks of age. With appropriate early
intervention, children with hearing loss can be mainstreamed in regular elementary
and secondary education classrooms. 13 Recent research
has concluded that children born with a hearing loss who are identified and
given appropriate intervention before 6 months of age demonstrated significantly
better speech and reading comprehension than children identified after 6 months
of age. 14 15
· Even mild hearing loss can significantly interfere
with the reception of spoken language and education performance. Research
indicates that children with unilateral hearing loss (in one ear) are ten
times as likely to be held back at least one grade compared to children with
normal hearing. 16 17 18 Similar academic achievement
lags have been reported for children with even slight hearing loss. 19
Children with mild hearing loss miss 25-50% of speech in the classroom and
may be inappropriately labeled as having a behavior problem. 20
· Recent clinical studies indicate that early
detection of hearing loss followed with appropriate intervention minimizes
the need for extensive habilitation during the school years and therefore
reduces the burden on the IDEA Part B program. 21 22
In contrast, a 30-year Gallaudet study revealed that half of the children
with hearing loss graduate from high school with a 4th grade reading level
or less. 23
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Facts
on Hearing Aids
· The hearing aid fitting process typically
consists of six stages: assessment, treatment planning, selection, verification,
orientation, and validation. The widespread use of computers has made the
process of fitting hearing aids more accurate and efficient.
· Over 60% of individuals with hearing loss
are fit with two hearing aids (binaural). The benefits of wearing two hearing
aids are enhanced ability to (a) hear better in the presence of background
noise, (b) determine where sound is coming from, and (c) hear soft sounds
at lower levels.
· One state-commissioned study published in
2000 has put the average cost for requiring hearing aid coverage by all insurers,
non-profit health plans and health maintenance organizations (HMOs) every
3 years at $16. This is based on a $1,400 contribution per hearing aid (beneficiaries
wanting more expensive hearing aids would pay the difference), excluding the
cost of batteries and maintenance that is estimated at about $300 per year. 24
· Hearing aids differ in design, type of circuitry,
size, and amount of amplification, but they do have similar components that
include a microphone, amplifier circuitry (to make the sound louder), a receiver
(to deliver the amplified sound into the ear); and batteries to power the
electronic parts.
· Approximately 30% of hearing aids in use today
are equipped with a telecoil. This is an optional feature that couples directly
with hearing aid compatible telephones and assistive listening devices, improving
intelligibility in noisy situations, poor acoustical environments, and at
long distances from the speaker.
· There are over 1,000 types and models of hearing
aids to satisfy an individual’s hearing loss needs.
Models of hearing aids
include:
· Completely-in-the canal (CIC) – the smallest model for mild
to moderate hearing loss;
· In-the-canal (ITC) – not as small as CIC, but greater power
to benefit a wide range of hearing loss;
· Behind-the-ear (BTE) – offers special programming and power
· Body – housed in a special case that can be carried in a pocket
providing the most power for the most severe hearing losses.
Types of hearing aids include:
· Conventional analog hearing aids produce the same amount of amplification
regardless of the loudness of the sound entering the hearing aid.
· Analog programmable hearing aids have a microchip, which allows the
aid to have settings programmed for different listening environments.
· Digital processing hearing aids have all the features of analog programmable
aids, but use “digitized sound processing” to convert sound waves
into digital signals. A computer chip in the aid analyzes the signals of the
environment to determine if the sound is noise or speech, and then makes modifications
to provide a clear, amplified signal. This allows more flexibility in the
programming of the aid so that the sound it transmits matches the hearing
loss.
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Facts
on Assistive Listening Devices (ALDs)
· ALDs are “binoculars for the ears” and may benefit many people with residual hearing. They are intended to augment
standard public address and audio systems by providing signals that can be
received directly by persons with special receivers or their own hearing aids.
· A minority of hearing aid owners concurrently
use ALDs. About 1 in 4 consumers use a phone amplifier, while less than 10%
of hearing instrument owners are users of ALD devices for enhancing their
hearing with TV, at movies, in places of worship, or in conferring. 25
· ALDs “stretch” the performance
of a hearing aid by increasing the signal to noise ratio (SNR). This is significant
as SNR has to be higher for many people with hearing loss for them to hear
speech over background noise
· ALDs reduce the effect of distance between
the person with hearing loss and the sound source; override poor acoustics;
and minimize background noise.
· There are three types of wireless ALDs (audioloop,
FM, and Infrared). All three types can be used with or without hearing aids,
and can be used with an array of receiver attachments for consumers with varying
needs and preferences. This includes neck loops, silhouette inductors, headphones,
direct audio input and other linkages.
· Each type of ALD has advantages and disadvantages.
The type of ALD appropriate for a particular application depends on the characteristics
of the setting, the nature of the program, and the intended audience.
· ALDs may be installed in large areas, portable
for personal use, or in the case of FM systems, built into a hearing aid.
· ALDs are an example of auxiliary aids and
services and reasonable accommodations required by the Americans with Disabilities
act (ADA ) to be provided by public facilities, state and local governments,
and employers, to enable people with hearing loss to participate in their
programs and services.
· ALDs typically have not been covered by any
public or private health insurance plans, and are not available in mainstream
retail outlets. Most ALDs must be purchased through catalogs of ALD distributors
or from some hearing health professionals. Access, availability and therefore
awareness of ALDs by consumers is a limiting factor to their acceptance and
use.
· Other assistive technology that can benefit
people with hearing loss include alerting devices, such as special smoke detectors,
doorbells, telephone ring signalers, telephones, and alarm clocks. These may
produce laud signals, visual signals, or tactile signals. Captioning and CART
(Computer Assisted Realtime Transcription) also provide great benefit.
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For
More Information Contact:
Alexander Graham Bell
Association for the Deaf and Hard of Hearing
Contact Person: Michele Duchin
Tel: 202-337-5220
Web Site: http://www.agbell.org
American Academy of Audiology
Contact Person: Jodi Chappell, Director of Health Care Policy
Tel: 703-790-8466
Web Site: http://www.audiology.org
American Speech Language Hearing Association
Contact Person: Jim Potter, Director of Government Relations and Public Policy
Tel: 301-897-5700
Web Site: http://www.asha.org
Deafness Research Foundation
Contact Person: Susan Greco, Executive Director
Tel: 202-289-5850
Web Site: http://www.hearinghealth.net
and http://www.hearinghealthmagazine.com
Hearing Industries Association
Contact Person: Carole Rogin, Executive Director
Tel: 703-684-5744
Web Site: http://www.hearing.org
Self Help for the Hard of Hearing People
Contact Person: Brenda Battat, Director of Public Policy and State Development
Tel: 301-657-2248 (V) 2249 (TTY)
Web Site: http://www.hearingloss.org
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References
1 National
Center on Hearing Assessment and Management. http://www.infanthearing.org/research/summary/prevalence.html.
2 Centers for Disease Control and Prevention.
National Center for Birth Defects and Developmental Disabilities, Early Hearing
Detection and Intervention Program. http://www.cdc.gov/ncbddd/ehdi/default.htm.
3 Grosse S. Cost comparison of screening
newborns for hearing impairment and biochemical disorders. Centers for Disease
Control and Prevention. Paper presented at the Newborn Screening and Genetics
Conference, May 2001.
4 Harrison M, Roush J. Age of suspicion,
identification and intervention for infants and young children with hearing
loss: a national study. Ear and Hearing. 1996;17:55-62.
5 Elssmann SA, Matkin ND, Sabo MP.
Early identification of congenital sensorineural hearing impairment. The
Hearing Journal. 1987;40(9):13-17.
6 National Center on Hearing Assessment and
Management. http://www.infanthearing.org/research/summary/prevalence.html.
7 Johnson JL, Mauk GW, Takekawa KM, Simon PR,
Sia CCJ, Blackwell PM. Implementing a statewide system of services
for infants and toddlers with hearing disabilities. Seminars in Hearing.
1993;14:105-119.
8 Joint Committee on Infant Hearing.
Year 2000 position statement: principles and guidelines for early hearing
detection and intervention programs. American Journal of Audiology.
2000; 9:9-29. http://professional.asha.org/resources/legislative/ih_index.cfm.
9 Healthy People 2010: Volume II (second
edition), http://www.health.gov/healthypeople/document/html/objectives/28-11.htm
10 National Institutes of Health.
Early identification of hearing impairment in infants and younger children.
National Institutes of Health, Rockville, MD 1993.
11 Newborn Hearing Screening: Recommendations
and Rationale. U.S. Preventive Services Task Force, Agency for Healthcare
Research and Quality, Rockville, MD; 2001 http://www.ahrq.gov/clinic/3rduspstf/newhearrr.htm.
12 Grosse S. Cost comparison of screening newborns
for hearing impairment and biochemical disorders. Centers for Disease
Control and Prevention. Paper presented at the Newborn Screening and Genetics
Conference, May 2001.
13 Joint Committee on Infant Hearing. Year
2000 position statement: principles and guidelines for early hearing detection
and intervention programs. American Journal of Audiology. 2000; 9:9-29.
http://professional.asha.org/resources/legislative/ih_index.cfm.
14 Yoshinaga-Itano C, Apuzzo ML. Identification
of hearing loss after 18 months of age is not early enough. American Annuals
of the Deaf. 1998;143(5):380-387.
15 Yoshinaga-Itano C, Sedey AL, Coulter BA, Mehl AL.
Language of early and later-identified children with hearing loss. Pediatrics.
1998;102:1168-1171.
16 Bess F. The minimally hearing-impaired
child. Ear and Hearing, 1985; 6:43-47.
17 Bess, F., Dodd-Murphy, J. & Parker,
R. Children with minimal sensorineural hearing loss: Prevalence,
educational performance, and functional status. Ear and Hearing,
1998; 19(5) 339-354.
18 Oyler R, Oyler A, and Matkin N.
Unilateral hearing loss: Demographics and educational impact. Language,
Speech and Hearing Services in Schools; 1988; 19: 201-209.
19 Quigley S. Effect of hearing impairment
in normal language development. Pediatric Audiology, Englewood Cliffs,
NJ: Prentice-Hall; 1978.
20 Flexer, C. Facilitating hearing
and listening in young children. San Diego, CA: Singular; 1994.
21 Centers for Disease Control and Prevention.
National Center for Birth Defects and Developmental Disabilities, Early Hearing
Detection and Intervention Program. What is EHDI? http://www.cdc.gov/ncbddd/ehdi/ehdi.htm.
22 Ross, M. Performance of Hard of
Hearing Children – Academic Achievement. Our Forgotten Children – Hard of Hearing Pupils in the Schools, Third edition; Bethesda, MD, Self Help
for Hard of Hearing People; 2001; 28-30.
23 Gallaudet Research Institute. Stanford
Achievement Test, 9th Edition, Form S, Norms Booklet for Deaf and Hard of
Hearing Students; Washington, DC: Gallaudet University; 1996 http://gri.gallaudet.edu/Literacy.
24 Maryland Health Care Commission, Mercer
study (2000)
25 MARKETRAK VI. “Factors Impacting
Consumer Choice of Dispenser and Hearing Aid Brand; Use of ALDs and Computers”
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