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The
following protocol is intended to support programs for
early detection of hearing impairment, which should
include medical evaluation/clearance for hearing aid
use for infants and children. It is also a guide to
appropriate ongoing audiology services in Listening
and Spoken Language programs.
The
Academy recognizes and recommends an audiological protocol
that includes the test battery approach as an optimum
means to access spoken language. This means that no
single test should be used in isolation to define and
describe the nature and extent of a hearing loss. Ideally,
every Listening and Spoken Language program will have
on-site audiological services, but, regardless of setting,
close collaboration of audiologists, therapists, and
parents is essential. Parents should be present and
participate in all assessments as well as in Auditory-Verbal
therapy sessions. The Auditory-Verbal therapist should
also be present at audiological assessments whenever
possible or send a report identifying his/her questions
or concerns regarding the child's hearing and amplification.
Procedures
to be included in all assessments regardless of child's
age:
-
Medical/Developmental History
-
Parent Observation Report
-
Otoscopic Inspection
-
Acoustic Immittance including tympanometry with high
frequency probe tone and acoustic reflex tests
Audiological
Diagnostic Assessment:
- Auditory
Brainstem Response (ABR) Assessment
- Threshold
search to click stimulus in 10dB steps with a 0dB
(no stimulus) comparison
- Comparison
of ABR by rarefaction clicks and condensation clicks
presented at 80-90dBnHL using a click rate >
30/second to rule out auditory neuropath
- Threshold
search to a 500 Hz and 3000 Hz tone pip
- Bone
conduction ABR using click stimuli
ABR
should not stand alone for diagnostic purposes. Absence
of a detectable ABR does not necessarily indicate
an absence of usable residual hearing. Special imaging
(CT scan and/or MRI) may be required to rule out absence
or abnormality of the cochlear structures, such as
a Mondini Dysplasia or Enlarged Vestibular Aqueduct.
- Otoacoustic
emissions (TEOAE and/or DPOAE)
- Behavioral
Observation Audiometry (BOA) using speech as well
as 500-2000 Hz warbled tones and/or narrowband noise,
by air conduction and bone conduction to identify
minimum response levels and to obtain startle response.
- Evaluation
of auditory skill status and tests of speech perception.
- Discussion
of results, questions, and recommendations with parents.
- Written
report of all tests and results, including:
- Descriptions
of test procedures, conditions of testing, and reliability
estimate
-
A complete audiogram with symbol key, calibration,
and stimuli identified, as well as plotting results
on a "Familiar Sounds" audiogram to support
parent/teacher counseling
- Identification
of hearing device, including manufacturer, model,
output and response, compression or special feature
settings, earmold specifications, and quality of
fit
- Copies
to parents, primary care provider, Auditory-Verbal
therapist and other health/education providers as
requested in writing by parents
- Referral
to medical, otolaryngological, or other resources
(genetic counseling, social services, psychological
counseling, occupational therapy, etc.) as appropriate.
Amplification
Assessment
- Electro-acoustic
analysis of hearing aids
- On
day of fitting
- Every
30 days at user volume as well as full volume
- Upon
return from repairs
- If
parental concerns arise from behavioral observation
or listening check
- Real-Ear-to-Coupler
Measures (e.g., Desired Sensation Level [DSL])
- To
establish fitting parameters for hearing aids using
prescriptive methods
- To
verify instrument settings in order to achieve target
gain and output
III. Probe Microphone Measures
- To
document hearing aid performance at initial fitting
- Upon
return from repairs
- To
assess changes in earmold style
IV. Sound Field Aided Response
- To
demonstrate response to speech for parent education
purposes
- To
assess speech perception at average and at soft
conversational levels in quiet and in the presence
of noise to evaluate the effectiveness of amplification
technology
- Assessment
of distance hearing using the Ling 6 Sound Test
to demonstrate the range of audibility provided
by the technology.
NOTE:
Functional gain measure is an appropriate verification
procedure for bone conduction hearing aids, cochlear implants,
and vibrotactile aids only. Verification of amplification
requires a real ear to coupler (RECD) measure appropriate
for children.
Audiological
Monitoring
-
Initial screening and diagnosis and confirmation should
be completed within the first three (3) months of
life—ideally as soon as possible after birth--in
order to ensure that habilitation is underway by age
six months.
-
Routine evaluation should occur ideally at 4-6 week
intervals during the first 12-18 months of life and
at 3-month intervals through age 3, although new earmolds
may need to be obtained more frequently.
-
Assessment at 6-month intervals from age 4 is appropriate
if progress is satisfactory.
-
Immediate evaluation should be undertaken if parent
or caretaker concern is expressed or if behavioral
observation by parent, therapist, or teacher expresses
concern, or if behavioral observation suggests a change
in hearing or device function.
More
frequent evaluation is appropriate when middle ear disease
is chronic or recurrent or when risk factors for progressive
hearing loss are present.
Cochlear
Implant Monitoring
- If
and when optimal access to spoken language is not
achieved for an infant or child through conventional
amplification, information should be provided regarding
cochlear implant technology, including benefits and
risks as documented in published, peer-reviewed literature
along with referral to a cochlear implant center.
-
Following initial mapping of a cochlear implant, re-mapping
should be conducted on the schedule recommended by
the cochlear implant team given the child's age, device
implanted, number of electrodes activated, and additional
individual considerations.
-
Even if a map can be programmed to achieve optimal
access to the speech spectrum within the first three
months of use, ongoing evaluation at six-month intervals
for at least three years after initial stimulation
is recommended. After this period, routine assessment
of cochlear implant performance should occur at 6
– 12 month intervals if progress is satisfactory.
-
Immediate evaluation is recommended if parent, caregiver,
and/or therapist observe behavior suggesting a change
in performance or express concern regarding device
function.
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