Hearing Loss and Children
As a result of improved technology,
permanent hearing loss can be identified soon after birth.
Regardless of age, a child with a sensorineural hearing loss (a
hearing problem in the inner ear) should be evaluated by an audiologist
to determine which type of hearing aid may be of most benefit.
Why Are Hearing Aids Important?
Children who have normal hearing begin using single words at about
one year of age.
In reality, a great deal of language is learned before children
utter their first word.
Hearing loss can disrupt language development because learning spoken
language depends on the ability to hear speech.
Some studies suggest that the ability to learn language peaks between
two to four years of age.
For this reason the earlier that
finding and addressing any hearing loss begins, the greater chances
of developing listening abilities and using spoken language.
The use of hearing aids is an integral part of this process.
Audiologists usually recommend hearing
aids as soon as possible after a loss is identified.
Ideally, an audiology facility that specializes in serving young
children will have a cost-saving loaner hearing-aid program where
a loaner hearing aid can be selected immediately after a hearing
loss is determined.
As more complete information about a child's
hearing loss is obtained, a hearing aid evaluation can be completed
to recommend hearing aids for purchase.
What Tests are Needed Before Recommending Hearing Aids?
Before hearing aids
can be purchased for a child, an audiologist must determine the
degree of hearing loss.
This can be done using special test methods for infants, toddlers
and young children.
For very young infants, the auditory
brainstem response test (ABR) may be used.
Electrodes are placed on the child's scalp using an adhesive, then
as the child sleeps, sounds are played through earphones.
Responses to the sounds are used to determine the degree of hearing
loss.
After six months of age, infants, toddlers and older children may
be tested with gamelike activities such as visual reinforcement
audiometry (VRA) or Conditioned Play Audiometry (CPA).
In this kind of testing children respond
to a number of different high and low pitch (frequency) sounds,
as well as to speech.
The softest levels at which a response is observed indicate how
much hearing loss is present. For these, a child's responses to
sounds are observed by audiologists.
An older child may press a button or raise a hand in response to
sounds.
Although behavioral responses can provide more complete detail about
hearing sensitivity across all frequencies, ABR responses may be
the only hearing information available from very young children
who cannot be tested with behavioral methods.
How are Hearing Aids Selected and Evaluated for Children?
After determining the degree of hearing loss and receiving medical
clearance to use hearing aids, the audiologist begins the hearing
aid evaluation process.
There are several hearing-aid evaluation
techniques that are used to select hearing aids for children. Regardless
of the technique used, the goal of amplification is to enable conversational
speech to be heard at a comfortable level.
Many audiologists use mathematics
to compute values for the hearing aid response based on the amount
of hearing loss present so the performance of different hearing
aids can be compared to the calculated targets.
Two testing methods are used to determine
hearing aid response. The first way of evaluating a hearing aid
is called functional gain testing.
Functional gain testing is performed in a sound booth using behavioral
testing methods similar to those mentioned above.
The softest level at which a child
responds to sound while wearing a hearing aid is compared to the
softest level at which the child responds to sound without a hearing
aid.
The difference between aided and unaided responses is called functional
gain.
Another method of evaluating
hearing aids is probe-microphone testing.
In this test, a tiny microphone is placed in the ear canal next
to the earmold to measure the performance of a hearing aid in the
ear, and responses are analyzed to determine hearing ability.
One advantage of this method over
functional gain testing is that the maximum level of sounds processed
by the hearing aid can be measured directly and adjusted on an individual
basis to safe and comfortable levels.
Another advantage is that probe
microphone measurements also can be completed quickly.
A probe microphone system can also be used to calculate real-ear-to-coupler
differences (RECD).
This is one of the newest methods of estimating hearing-aid performance.
RECD values are used to estimate
the real ear responses of different hearing aids without having
to perform probe- microphone testing with each individual hearing
aid on the child's ear.
The RECD procedure can be performed when there are concerns that
a child will not be able to sit still long enough to perform traditional
probe-microphone testing.
What Characteristics are Important
When Choosing Hearing Aids for Children?
There are several technical terms you may hear
when audiologists discuss the characteristics they consider when
selecting hearing aids for children.
The first, frequency response, is
the amount of amplification a hearing aid provides across a frequency
range. Amplification is usually provided only in regions where hearing
loss is present.
Gain is the amount of amplification
the hearing aid provides. Gain is expressed in decibels (dB).
For example, a powerful hearing aid would
have high gain. Saturation sound pressure level (SSPL) is the loudest
sound the hearing aid can produce, regardless of the incoming signal
or the amount of gain.
The SSPL of a hearing aid should
be set so that the hearing aid never becomes uncomfortably loud
or potentially damaging to the ear.
The audiologist will also discuss other important
options about hearing aids, including flexibility in adjusting frequency
response, gain and saturation response.
This flexibility is useful in case
hearing changes or as additional information about the hearing loss
is obtained.
A second consideration is the compatibility of a hearing aid with
assistive devices because many children with hearing loss use additional
amplification devices, such as FM auditory trainers.
A third consideration is the availability
of volume-control covers and tamper-resistant battery compartments
when selecting hearing aids for infants and toddlers.
Why is a Behind-the-Ear Hearing
Aid Style Usually Recommended for Children?
Safety is the overriding concern for the choice
of behind-the-ear (BTE) vs. in-the-ear hearing aids for children.
BTE hearing aids can be used with earmolds
made of soft material as a safety precaution with physically active
children.
In general, BTE hearing aids also require fewer repairs than in-the-ear
hearing aids, and they are more compatible with assistive devices
such as FM auditory trainers.
Although assistive devices are not typically used with infants and
toddlers, many children with hearing loss use FM auditory trainers
and other assistive devices when they begin school.
What Happens After the Hearing Aid Evaluation?
The Food and Drug Administration (FDA) recommends
a thirty day trial period with each new hearing aid. During this
time, the hearing aids should be used as much as possible in everyday
situations.
The audiologist will monitor hearing aid adjustment
and benefit during the trial period to determine if any adjustments
or changes are necessary. Children's hearing and hearing aid performance
should be reevaluated frequently to monitor hearing sensitivity
and hearing aid function.
These appointments should be scheduled as recommended
by the audiologist. Identifying a hearing loss and finding appropriate
hearing aids for a child is a process that may take weeks or months.
Parents play an important part in this process
of evaluating and using hearing aid amplification. They provide
valuable information about a child's responses and are critical
to their child's successful use of hearing aids.
How Will Having Hearing Aids Benefit My Child?
Ideally, hearing aids will enable conversational
speech to be heard at a comfortable level. The success of achieving
this goal depends on the degree and configuration of a hearing loss.
When severe-to-profound hearing loss is present,
hearing aids may not be able to amplify speech to levels where it
can be understood clearly; however, hearing aids may still improve
sound and speech awareness as well as provide helpful additions
to visual and facial cues.
Hearing aids do not restore hearing to normal and
may not be effective in all listening situations such as noisy backgrounds
or listening to speech at a distance. In more difficult listening
situations, an FM auditory trainer or a similar assistive device
may be beneficial.
How Can I Receive Additional Information About Hearing Aids for
Infants and Children?
Hearing loss can affect communication.
Understanding he
aring loss and the role hearing aids can play are
helpful in making informed decisions.

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