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17 Evaluation and Management of Vestibular Function in Infants and Children with Hearing Loss
Madell et al., Pediatric Audiology: Diagnosis, Technology, and Management, 3rd Ed. (ISBN 978-1-62623-401-7),
copyright © 2019 Thieme Medical Publishers. All rights reserved. Usage subject to terms and conditions of license.
17.3 Causes of Vestibular
Dysfunction
Common causes of unilateral and bilateral vestibular dysfunction in the pediatric population, both congenital and acquired,
are outlined in Fig. 17.1. It is important to remember, that unlike
adult acquired acute dysfunctions, which tend to be unilateral
(e.g., vestibular neuritis, resulting in vertigo), the majority
of pediatric conditions have a greater prevalence of bilateral
involvement. This is likely why pediatric dizziness and vertigo
have low prevalence in the general pediatric population.
2,10
With
the exception of benign paroxysmal vertigo (BPV) of childhood,
which produces vertigo, nausea, and emesis, the infant or young
child is not in apparent distress.
Fig . 17.1 Common causes of unilateral and bilateral vestibular
dysfunction in children.
Pitfall
One normal-hearing ear does not preclude the possibility of a
bilateral vestibular loss.
means hearing loss may not be consistently seen. So, if there were
no failure of a high-risk hearing screening at birth, but only the
vestibular symptoms occurred, the vestibular loss would probably
be missed. Autosomal recessive disorders in the nonsyndromic
category account for over two dozen loci.
Acquired conditions may include BPV of childhood, which
generally is considered the leading cause of pediatric dizziness.
BPV of infancy (not to be confused with benign paroxysmal
positional vertigo [BPPV], discussed in the following paragraph),
a classification of migraine, is the condition most likely to produce
symptoms of vertigo in children.
19
It could be argued that since
this is a migraine variant, it is genetic. It is classified as one of the
six subtypes of migraine by the International Headache Society.20
Basser coined the name in 1964 to describe brief bouts of vertigo,
nausea, vomiting, and change in pallor.21 Onset usually occurs
between ages 1 and 4, and it will virtually disappear in children
by age 5 or 6. There are no lingering eects between episodes,
and all radiographic and EEG tests are unremarkable. So, this is a
diagnosis of exclusion, but because of its genetics and tone, more
of the biological parents are probably migraineurs. It is estimated
that ~ 50% of these children will become migraineurs by puberty.
Benign paroxysmal vertigo of infancy is defined as recurrent with
at least five occurrences, which resolve spontaneously or within
hours. Investigators are reporting successful management with
both abortive and prophylactic pharmacologic treatments.
22
Head trauma may cause the same form of BPPV as seen in
adults. This is usually seen in older children and adolescents who
are involved in sports or activities in which they are susceptible
to even minor head bumps playing soccer or other contact sports.
Infants at any age, however, may experience BPPV with head
trauma. These children can be quickly identified with appropriate
modified Hallpike protocols, be successfully treated with canalith
repositioning maneuvers (CRM), and resume their normal activities without any restrictions, so long as there are no issues of concussion secondary to a head trauma to complicate their recovery.
Of great concern, particularly in emerging economies, is overdosing with aminoglycosides for treatment of bacterial infections
in infants and young children.23 This has become a growing prob-
lem and is presently being addressed by a joint eort between the
World Health Organization (WHO) and the American Academy of
Otolaryngology—Head and Neck Surgery (AAO-HNS) Foundation.
Congenital disorders by far are the leading cause of pediatric
11
vestibular dysfunction.
and nonsyndromic disorders are known to have an audiovestibular
expressivity.11 Recent investigators have reported as high as 90%
abnormal VEMP responses in children with congenital SNHL. The
emerging use of neonate and infant VEMP data suggests a much
high incidence of vestibular dysfunction than the 30 to 50% previously estimated.
respective age ranges are presented in Table 17.1.
Table 17.2 presents syndromes with known and unspecified
expressivity as well as a brief description of each to familiarize
the reader better with common expressivities associated with
the conditions. It has been well established that audiovestibular
anomalies are the most frequently found defect across all known
mitochondrial diseases. In addition, there are nearly 70 identified dierent nonsyndromic loci for hereditary audiovestibular
impairment. Of these, at least 30 are dominantly inherited, which
It is estimated that over 500 syndromic
12,13,14,15
Recent pediatric VEMP studies and their
12,13,14,15,16,17,18
Table 17.1 Review of pediatric VEMP studies
Investigators Study
Pereira et al 2015
Maes et al 2014
Ecevit et al 2012
Zhou et al 2009
Picciotti et al 2007
Kelsch et al 2006
Sheykholeslami et al 2005
Abbreviations: cVEMP, cervical vestibular evoked myogenic potentials; SNHL,
sensorineural hearing loss.
16
17
18
15
13
12
Normative data on children ages 8–13
years
Compared cVEMP on normal and
hearing impaired children ages 3 to
13 years
Compared cVEMP in late preterm and
term births
21/23 (91%) SNHL had abnormal
amplitudes
Ages 3–15 years
Ages 3–11 years
14
Neonates
191
II Diagnosing Hearing Disorders in Infants and Children
Madell et al., Pediatric Audiology: Diagnosis, Technology, and Management, 3rd Ed. (ISBN 978-1-62623-401-7),
copyright © 2019 Thieme Medical Publishers. All rights reserved. Usage subject to terms and conditions of license.
Table 17.2 Expressivity and description of syndromes aecting the audiovestibular system
Syndrome Expressivity
(Known or Unspecied)
Usher Known Type I: congenital-bilateral profound SNHL, retinitis pigmentosa
Brachiootorenal Known Preauricular pits or tags, branchial cysts, hearing loss, and/or abnormal development of the
Pendred Known Congenital, severe–profound SNHL, abnormality of bony labyrinth; abnormal thyroid
Neurobromatosis type 2 (NF2) Known Bilateral vestibular schwannomas, tinnitus, hearing loss, and balance dysfunction;
Waardenburg Unspecied Congenital SNHL, pigmentary disturbances of iris, hair, skin; vestibular disturbances
Von Hippel-Lindau Unspecifed Hemangioblastomas of brain, spinal cord, and retina; renal cysts and renal cell carcinoma
CHARGE Known Coloboma–heart–atresia–retardation–genital–ear; vestibular symptoms prevalent
Marshall Known Saddle nose, myopia, early-onset cataracts, and short stature; vestibular symptoms
Spinocerebellar ataxia Known Complex and progressive; 23 distinct genetic disorders; may also include hearing loss
Abbreviation: SNHL, sensorineural hearing loss.
Description
Type II: mild-severe progressive high-frequency SNHL
kidneys
development with goiter in early puberty of adulthood
schwannomas of other peripheral nerves, meningiomas, and juvenile cataract
without hearing loss
(40%); dizziness/imbalance and hearing loss may be initial symptoms, may mimic Ménière
disease
prevalent
Educating attending physicians and healthcare providers in these
rural or remote regions has become a primary goal of these
organizations.
There are now emerging data regarding vestibular function post
cochlear implantation for the pediatric population24 and the differences between electrode types.25 Researchers are increasingly
Pearl
An infant’s vestibular and balance function can be reliably evaluated as early as at 3 months of age using both behavioral and
electrophysiologic protocols.
considering not only hearing preservation but vestibular function
as well. Presently there is a need for controlled prospective stud-
ies pre- and postimplantation to assess the eect on children’s
balance function. Researchers in the meantime are exploring
innovations that combine cochlear and vestibular implants for
individuals with bilateral vestibular loss.
26
Delayed maturational motor milestones may be the earliest
signs of a vestibular dysfunction. When interviewing parents of
an infant with an identified hearing loss, it is important to ask
them about the child’s motor development timeline. Indicators of
peripheral-central vestibular dysfunction may include the infant’s
inability to hold the head upright, crawl, stand, and then walk.
17.4 Evaluation Techniques
Just as normal hearing is essential for acquisition of speech and
language, intact vestibular function is critical to the infant’s
physical and motor development. The majority of equilibrium
problems that occur in infants and children manifest as delayed
gross motor and balance problems, not as vertigo or dizziness.
Table 17.3 Summary of maturational motor milestones
3 months 7 months 9 months 12 months 24 months
Raises head and chest when
lying on stomach
Starts to use eyes and hands
in coordination
Begins to support head Ability to track moving
Pushes down with legs when
feet placed on oor
Moves eyes in all directions Supports head when sitting Walks holding on to
Sits with and then without
support of hands
Supports weight on legs Walking with assistance Crawls forward on belly
objects improves
Rolls over Pulls self up to standing
Crawling on hands and
knees
Upper body—turns from
sitting to crawling position
Just as with auditory testing, there is an array of clinicalbehavioral tests available. Even prior to the use of any standardized test, as with speech and language development, there are
ell-recognized developmental milestones. These are age specific
w
with normative data in the form of maturational motor milestones
as shown in Table 17.3.
Sits without assistance Walks alone by 18 months
by pulling with arms and
pushing with legs
Creeps on hands and knees
and supports trunk
position
furniture
Stands momentarily without
support
27
Begins to run
Can push a wheeled toy
192
17 Evaluation and Management of Vestibular Function in Infants and Children with Hearing Loss
Madell et al., Pediatric Audiology: Diagnosis, Technology, and Management, 3rd Ed. (ISBN 978-1-62623-401-7),
copyright © 2019 Thieme Medical Publishers. All rights reserved. Usage subject to terms and conditions of license.
Pitfall
Early examination and evaluation should be considered if vestibular issues are of concern. Delayed milestones may be observed
at a very early age.
The evaluation of functional balance in young children has been
well studied, and there are normative data for a wide range of ages.
One of the most commonly used developmental scales, the Denver
Developmental Screening Test,
other health and social service providers to look at developmental
problems in preschool children in the areas of social contact, fine
motor skills, language, and gross motor skills. Gross motor skills
involve the ability to use large muscles for movements such as
lifting the head, crawling, or walking. These skills begin to develop
in infancy and early childhood. The Pediatric Balance Scale (PBS)
has been evaluated for children ranging from 2 years 4 months
to 13 years, 7 months. It has been reported as most accurate for
ages 3 to 6 years, and the inuence of height, weight, and BMI on
performance has been studied.
Although delay in maturational milestones may indicate prob-
lems within the vestibulospinal reex, an infant’s gross motor
skills depend on both muscle tone and strength. Low muscle tone,
or hypotonia, is a characteristic of several disabling conditions
such as Down syndrome, genetic or muscle disorders, or CNS
disorders. These conditions may, of course, exist in conjunction
with vestibular dysfunction secondary to congenital trauma or
syndromes.
A good case history is essential in speaking with the parents
and asking about when these milestones were achieved. Likewise,
spending time observing the infant playing, rolling, and interacting with a parent will provide a great deal of valuable information.
Just as with hearing testing, much of the evaluation is childdirected. Vestibular evaluations can be accurately conducted as
early as 3 months of age with neonates who are suspected of
congenital hearing loss. Waiting until 3 months of age is preferable because time is needed for the neck musculature to mature
enough for the child to begin to hold the head upright. The neck
muscles become stronger during these first few months of life. At
first, newborns can hold their heads up only for a couple of sec-
onds while on their stomachs. The muscles are strengthened each
time the head is held up. By 3 months of age, infants lying on their
stomachs can support their heads and chests up to their forearms.
28,29
is used by pediatricians and
30
help strengthen the upper body and are in preparation for sitting
up. Infants may also rock while on their stomachs, kick their legs,
and “swim” with their arms. These movements are necessary for
rolling over and crawling. By the end of this period, infants should
be able to roll over from stomach to back and back to stomach and
probably are able to sit without any support.
By 8 months of age, most infants can sit up without support.
They also figure out how to roll down to their stomachs and return
to a sitting position again. Some infants are in constant motion;
they arch their necks and look around while on their stomachs
and grab at their feet or objects while on their backs. All this
activity is preparing them for crawling, which is usually mastered
between 7 and 10 months of age. Crawling is important for the
development of integrated communication between the two sides
of the brain. Some infants never crawl but rather scoot on their
bottoms or move on their stomachs.
After crawling is mastered, infants will begin to pull themselves
up to a standing position. They then begin to take some steps
while holding on to something for support. This will change into
cruising around the furniture. As their balance improves, infants
may gradually take a few steps without holding on. Many infants’
first steps are taken around 12 months, but 2 months earlier or
later than this may be considered within a range of normal.
Lifting the child in space or changing the child’s position while
on a variety of movable surfaces can test righting reexes and
equilibrium responses. An example of this can be seen in Fig.
17.2. The three-month-old infant is placed prone, on an exercise
ball, which is a dynamic surface. The infant’s head and legs lift up
reexively, in what is known as a Landau reex, which emerges
at 3 months of age. This reex is also seen in an older child of
3.5 years in Fig. 17.3. As can be seen in the photos, both children
demonstrate a clear upturn of the head away from the oor.
Problems in integration of tonic neck reexes may implicate
related vestibular dysfunction because labyrinthine receptors
indicate body position only in conjunction with neck receptors.
In Fig. 17.4 a 3-year-old is sitting on the exercise ball, a highly
dynamic condition, and we watch to see whether the head and
torso remain stable and centered even when he is perturbed in
Pitfall
Concerns based solely on observations related to episodes of
dizziness or vertigo will not typically identify vestibular problems
in children. Many children with vestibular dysfunction appear to
be clumsy or prone to falls.
Once infants can lift up their heads, they’ll push up using their
arms and arch their back to lift up their chest. These movements
Fig . 17. 2 Placing 3-month-old infant prone on an exercise ball
produces a Landau reex.
193
II Diagnosing Hearing Disorders in Infants and Children
Madell et al., Pediatric Audiology: Diagnosis, Technology, and Management, 3rd Ed. (ISBN 978-1-62623-401-7),
copyright © 2019 Thieme Medical Publishers. All rights reserved. Usage subject to terms and conditions of license.
Fig . 17. 3 Three-year-old demonstrates appropriate vestibular
response.
any direction. Lateral tilt, for example, activates utricular recep-
tors, which in turn excite vestibulospinal neurons and inuence
the activity of limb muscles. Age guidelines for head righting,
equilibrium responses, and other postural reactions that are
dependent, at least in part, on vestibular processing have been
documented by many developmental researchers and are well
known to therapists who work in pediatrics.
Pearl
Evaluation protocols may include use of motor milestones and
optokinetic reexes when advanced testing such as cVEMP is not
available.
Muscle tone is another important aspect within the evaluation,
as it is closely associated with the integrity of the vestibular
system. Loss of vestibular input may result in prolonged muscular
debility that may even extend to the visceral muscles. For children
who are too young or small to be tested with CDP, or when the CDP
is unavailable, may be evaluated using the Clinical Test of Sensory
Integration of Balance (CTSIB), which is standardized on children
as young as 3 years of age. In Fig. 17.5 a Limits of Stability (LOS)
strategy can be utilized with the child, first with eyes open, then
with closed, and finally using a play-type protocol that requires
the child, while standing on a dynamic surface, to reach or stretch
outside their static base of support.
The visual observation of optokinetic nystagmus (OKN), using
a rotating drum that fills the infant’s visual field (at least 80%),
Fig . 17.4 Three-year-old shows good neck and trunk stability while on
the dynamic exercise ball.
is also an excellent method of assessing the VOR. It has been
demonstrated that OKN appears as early as 1 month, and it is
nicely developed at 3 months of age. Conditions where there is
a bilateral vestibular dysfunction (BVD) will not produce a binocular bidirectional response. In those cases where there may
be a nonc
response will be asymmetric, with no or reduced response with
the stimuli moving in the direction of the involved labyrinth. It
is this author’s experience that it is rare to see infants or young
children with noncompensated UVD secondary to an acquired
otologic lesion.
ompensated unilateral vestibular dysfunction (UVD),
17.5 Conclusion
Infants with vestibular, equilibrium, and delayed maturational
motor control disorders can now be identified at an earlier age,
thanks to the success of newborn hearing screening. Unlike older
children or adults with acquired unilateral vestibular deficits,
infants with BVD will not benefit from traditional vestibular
rehabilitation strategies. They will benefit, however, from ongo-
ing sensory integration, substitution, and conditioning therapy
with trained pediatric physical and occupational therapists. The
knowledge of the status of vestibular modality will provide the
194
17 Evaluation and Management of Vestibular Function in Infants and Children with Hearing Loss
Madell et al., Pediatric Audiology: Diagnosis, Technology, and Management, 3rd Ed. (ISBN 978-1-62623-401-7),
copyright © 2019 Thieme Medical Publishers. All rights reserved. Usage subject to terms and conditions of license.
Fig . 17.6 cVEMP testing may be reliably obtained at 3 months of age
from active, awake infants.
Discussion Questions
Fig . 17. 5 Limits of Stability (LOS) strategy is utilized with child
standing on a dynamic surface.
therapists with valuable information about therapy protocols
and ultimately the child’s prognosis over time. Although it does
require at least two intact sensory modalities to produce normal
equilibrium function, this early vestibular therapy jump start
will be critical in providing infants and children with a more
normal and active lifestyle during their formative years.
It is well documented that the audiovestibular system in infants
is just as susceptible to vestibular deficits as it is to hearing deficits.
Audiologists can play an important role in the early identification
of infants, especially those with hearing loss, who may be at risk
for balance problems as well. Young infants as early as 3 months
of age are not candidates for VNG (with the exception of cVEMP
testing as shown in Fig. 17.6), posturography, or rotary chair
examinations, even if the technologies are available. Therefore,
an understanding of the vestibular system’s role in postural
and motor coordination performance can serve as an invaluable
contribution for early identification and intervention of vestibular
problems.
1. When in an embryo’s development does the vestibular labyrinth develop?
2. What is the relationship between congenital sensorineural
hearing loss and vestibular dysfunction?
3. Is it possible for children to have BPPV, and if so, how should
they be treated?
4. What is the relationship between migraine and BPV of childhood? Can the latter be treated medically?
5. What is the best intervention strategy for children identied
with balance dysfunction?
6. What is the eect of CI on balance function?
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18 Interpreting Audiologic Test Results and Using the Test Information to Plan Management
Madell et al., Pediatric Audiology: Diagnosis, Technology, and Management, 3rd Ed. (ISBN 978-1-62623-401-7),
copyright © 2019 Thieme Medical Publishers. All rights reserved. Usage subject to terms and conditions of license.
18 Interpreting Audiologic Test Results and Using the Test
Information to Plan Management
Jane R. Madell and Carol Flexer
Summary
This chapter features a practical, case-study format for interpreting audiologic test results and using the test information to plan
management. Validity and reliability measures are discussed
first, because audiologists rely on the results of tests to determine technological and therapeutic management. The cases in
this chapter emphasize the audiologist’s responsibility to study
the whole child: the child’s language, educational performance,
and social-emotional functioning before finalizing audiologic
recommendations. By considering all aspects of a child’s performance, the pediatric audiologist has a key role in ensuring the
child’s developmental progress.
Keywords
validity, reliability, interpreting test results, hearing aid fitting,
diagnostic recommendations, technology recommendations,
educational recommendations, literacy recommendations, strategic seating, classroom noise, teaching accommodations
Key Points
We establish degree of hearing loss not for its own sake, but
•
to assist in selecting technology and planning management.
Whenever a test is used as part of diagnostic protocol, the
•
validity and reliability measures of the test are important
because we are relying on the results of tests to determine
technological and therapeutic management.
Any behavioral or electrophysiologic audiologic test is valid
•
only if we are using the correct test protocol on the appropriate population.
Validation of the hearing aid tting is critical if we want to
•
know what a child is actually hearing.
Children speak what and how they hear.
•
Interpreting audiologic test results includes estimating the
•
child’s performance outside of the test situation and making
appropriate recommendations.
18.1 Interpretation and Plan
Management Using Audiologic
Test Results
Reasons for performing audiologic diagnostic assessments in
children include documentation of the hearing loss or processing
deficit, determining recommendations, and developing management protocols. In particular, the audiologist should constantly
be considering management while testing is in progress. For
consistency, it is best if the assessing audiologist is also the one
who is making the recommendations.
Observing a child during testing provides much more information than simply obtaining test results. Observing a child’s latency
of response, response posture, and auditory attention provides
information about how comfortable the child is when attending to
auditory stimuli. For example, two children with hearing loss may
have similar thresholds, but suppose the first child is having a very
dicult time attending and responding during the test situation,
while the second child is very auditorily attentive and responds
quickly and with assurance. Their dierent response behaviors
suggest that the children are taking in auditory information in
very dierent ways. As a result, the audiologist’s recommendations likely would be an expression of concern for the first child’s
auditory diculties. That is, the audiologist might question how
well the child can attend in the classroom. Also, if the child is using
technology, the audiologist may oer recommendations based on
how often the child wears the technology and the intensiveness of
the auditory therapy and parent practice.
Pearl
Children should obviously wear their technology full time (10—12
hours per day) but we know they do not always do so. Part of
audiologic management is helping families understand why fulltime use of technology is critical for the child’s auditory brain
development and acquisition of knowledge.
We establish degree of hearing loss not for its own sake, but
to assist in selecting technology. We know that if a child has a
mild hearing loss, appropriately set hearing aids will provide
auditory brain access to soft speech throughout the frequency
range. We also know that a child with a profound hearing loss
cannot receive sucient auditory brain access from hearing aids
but could receive access to the entire speech spectrum through
cochlear implants.
and interpretation of appropriate pediatric tests that lead to the
determination of management strategies.
The purpose of this chapter is to discuss issues in the interpretation of audiologic test results as the foundation of management
strategies for children with all degrees of hearing loss. Accordingly,
this chapter will provide an overview of validity and reliability
issues and discuss how these issues aect test selection and interpretation. Case studies will be utilized to exemplify interpretation
of assessment data.
1
There are nuances involved in the selection
18.2 Validity and Reliability
Whenever a test is used as part of a diagnostic protocol, the validity and reliability measures of the test are important, because we
are relying on the results of tests to determine technological and
therapeutic management.
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18.2.1 Validity
Validity is the degree to which a test measures what it purports
to measure.2 For a test to be accurately applied and interpreted,
the test must be valid. Validity is determined by a body of
research demonstrating the relationship between the test and
the behavior it is intended to measure. For example, one would
not want to use a math test to determine linguistic competency.
Audiologists would not use a broadband noise stimulus to obtain
frequency-specific information.
18.2.2 Reliability
Reliability is the consistency of a measure.3 Tests are considered
reliable if we obtain the same results repeatedly. In particular,
test–retest reliability is the consistency of the results among
dierent administrations of a test. Reliability assumes that there
will be limited or no change in the quality or construct being
measured. For example, if we cannot obtain repeatable pure tone
thresholds during one test session, we question the reliability of
the test results.
Pearl
Unless we use behavioral test methods to evaluate a child’s aided
functional performance, we simply do not know what a child is
hearing with hearing aids, cochlear implants, osseointegrated
implants, or remote microphones (RMs).
18.2.3 Application of Reliability and
Validity to Pediatric Testing
We need to ask ourselves the following questions: Are we
measuring what we think we are measuring? Are we using
the appropriate test for the child who is in front of us? Are we
performing the test accurately? Are we interpreting test results
correctly?
Any behavioral audiologic test is valid only if we use the correct
test protocol on the appropriate population. To the extent that the
appropriate procedures are not followed, or the test is performed
on populations other than those for whom it was intended, the
results cannot be accurately interpreted. (See Chapters 7, 8, and 9
in this text for a discussion of pediatric behavioral test protocols.)
When performing pure tone assessments, there are pediatric
procedures that are specific to certain developmental age levels. For
example, visual reinforcement audiometry (VRA) is an appropriate
test for a child who is cognitively between 5 and 36 months of age,
and conditioned play audiometry (CPA) is typically the appropriate
test for children beginning at ~ 30 to 36 months of age. If VRA is
used to test a child who is cognitively 64 months of age, the child
will likely become bored with the test and stop responding. Would
it then be correct to conclude that this child has a hearing loss?
Obviously not. On the other hand, if we are evaluating a child who
is cognitively 18 months of age but chronologically 64 months of
age, would it be appropriate for us to evaluate that child based on
his chronological age? Again, obviously not. While both VRA and
CPA are valid test protocols to obtain pure tone thresholds when
administered correctly, the results in the cases just described would
not be valid. Some toddlers younger than 30 months are capable
of reliably performing the CPA task, but results can be considered
accurate only if they are repeatable. Results obtained only once
cannot be considered reliable.
Pearl
For test results to be interpreted accurately and appropriately,
the correct test must be selected, and it must be administered
according to the protocol that was used to validate the test.
For more information about hearing test protocols for children,
see Chapter 6.
18.3 Interpreting Test Results
18.3.1 Case 1: Speech Perception
Interpretation Issues
Mark is 12 years old and in 6th grade in a mainstream educational
setting. He has a severe to profound sensorineural hearing loss
and has had bilateral implants since the age of 2 years. He recently
had an audiologic evaluation at his implant center. Threshold
testing with the implants revealed excellent benefit, with implant
soundfield thresholds between 15 and 20 dB hearing level (HL)
throughout the frequency range. Speech perception testing was
performed using the Phonetically Balanced Kindergarten (PBK)4
word lists in a monitored live-voice (MLV) format at 50 dB HL.
Mark had excellent speech perception test results with scores of
96% bilaterally, in two separate test sessions.
Are these test results valid and reliable? This is an example of
both a reliability and a validity problem. We might assume that
these results are reliable because they were obtained on two dierent occasions. The use of the PBK test is clearly not a valid protocol
for this child. MLV testing is also not appropriate for a child of this
age, since as soon as a child can perform on recorded tests, they
should be used. Every child needs to be tested with an age- and
linguistically appropriate test. The PBK test is designed for and
standardized on children 5 to 7 years of age and, therefore, would
be too easy for a 12-year-old, so results would overestimate his
speech perception skills. A child who is 12 years old and enrolled in
a mainstream educational setting needs to be assessed using a test
that is designed for a 12-year-old so that the audiologist can make
a judgment about how this child is likely to perform in a classroom
setting. In fact, when school ocials looked at the test results,
they decided that Mark did not need any services. When Mark
was retested using recorded consonant–nucleus–consonant (CNC)
words presented at 50 dB HL, which is certainly a more challenging
test, test results indicated scores of 66%, demonstrating that Mark is
missing a great deal of speech information, thus justifying the need
for accommodations in the classroom.
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18.3.2 Case 2: Making Recommendations
Based on Insucient Information
Joan is 3 years old. Her parents bring her in for evaluation
because her preschool teacher is reporting concern about Joan’s
ability to hear in the classroom and her poor speech. Joan is
frightened and won’t permit the use of either insert earphones
or supra-aural earphones. After attempting to coax her, the
audiologist decides to begin with soundfield testing and obtains
thresholds indicating a moderate hearing loss. Joan returns
for follow-up testing but still refuses to put anything in her
ears—either insert earphones, a tympanometric probe, or an
otoacoustic emissions (OAE) probe. Otologic evaluation by the
ear, nose, and throat (ENT) physician finds no medical concerns,
and he clears her for hearing aids. Because the audiologist cannot
obtain earphone testing, she proceeds to fit hearing aids based
on soundfield data, recognizing that the results can apply only to
the best-hearing ear. Real-ear testing is performed and verifies
that targets have been met based on soundfield thresholds that
were entered for each ear. Binaural aided soundfield testing per-
formed at subsequent visits validates that Joan is able to detect
the entire speech spectrum at soft conversational levels when
wearing both hearing aids.
At a later date, when Joan is finally tested with insert earphones,
results reveal that she has a moderate hearing loss in her right
ear and a profound hearing loss in her left ear. Soundfield testing
with hearing aids separately indicates that she is not receiving
sucient benefit in her left ear, which has the profound hearing
loss. Joan has spent considerable time without appropriate auditory brain access. The real-ear data could not be accurate for the
ft ear because targets were based on data that were not valid.
le
Management has not been adequate because Joan’s brain has not
received auditory information through her left ear; technology
needs to be changed for that ear (i.e., a more powerful hearing
aid or a cochlear implant). In addition, auditory therapy needs to
add a focus on improving listening skills for the left ear alone once
appropriate technology is obtained.
Both the audiologist and the auditory therapist share the
responsibility for not identifying the sensitivity discrepancy
between the right and left ears early on. Even if the audiologist
was unable to put earphones on Joan, she should have tested
each hearing aid separately in the sound room by obtaining aided
thresholds or speech perception information, or arranged for an
auditory brainstem response (ABR) test, either of which would
have identified the dierence in auditory brain access between
the ears. The auditory therapist should have done some auditory
work with each ear separately, which would also have identified
that there was a problem. The child has lost significant time in
auditory brain development. It is essential that everyone now
working with the child move quickly to try to improve auditory
brain access and build auditory/linguistic skills.
18.3.3 Case 3: Verication and Validation
of Hearing Aid Fitting
José is a 7-year-old child with a bilateral moderate to severe
sensorineural hearing loss. He comes into the clinic for his
annual audiological evaluation. When updating the case history,
the audiologist learns that José is in second grade and earning
average grades. His auditory therapist and speech-language
pathologist report that José is having diculty both hearing
and producing high-frequency consonants ([s], [f], and [θ]) and
word endings. Unaided testing confirms that his hearing loss
continues to be stable. Middle ear evaluation indicates no middle
ear disease. Acoustic reexes are absent, consistent with his
degree of hearing loss. After completing unaided testing, the
audiologist decides to verify the hearing aid fitting. She performs
real-ear measures and determines that the hearing aids are
meeting prescriptive target output levels. However, even though
high-frequency targets appear to be achieved as determined by
real-ear measurement, the audiologist observes that the reports
of the auditory therapist and speech-language pathologist are
correct; José is not producing high-frequency consonants and is
missing many word endings.
Should the audiologist assume the hearing aid settings are
correct and that remediation will need to be escalated by the
auditory therapist and the speech-language pathologist, or is
there additional testing the audiologist should perform? Real-
ear measures are a verification technique confirming the hearing
aids are working acoustically and how much sound is reaching
the tympanic membrane. However, without validation, it is not
possible to know what the child is actually hearing.
the auditory performance of the hearing aids, the audiologist
takes José back into the test booth to assess his aided performance. She obtains aided noise band thresholds and speech
perception measures for normal and soft conversational speech
in quiet and with competing noise. Care must be taken when
performing aided threshold testing to be sure noise reduction
algorithms are not confusing the results. Speech perception test-
ing is dicult to accomplish because José’s speech production
is poor. It is not always possible to determine whether José has
misheard a word or cannot produce the word. The most desirable test would be an open-set recorded test, but José’s speech
production will make such a test invalid. The purpose of speech
perception testing is to evaluate the child’s ability to perceive
speech sound distinctions accurately, not to assess his speech
production. We should never assume that the error is a production error. A child’s speech production errors may actually be
auditory perception errors. There is no way we can know what
the child is hearing unless the child can accurately repeat the
word or write or spell the answer.
Table 18.1 reports the narrowband noise thresholds obtained
for José and indicates that with hearing aids, José is not hearing
high-frequency sounds at suciently soft levels.
Because speech perception testing cannot be accomplished
with the PBK recorded test because of José’s speech production
errors, a picture-pointing task is considered. The Northwestern
University—Children’s Perception of Speech (NU-CHIPS)6 task,
while easy for José to accomplish, is not an appropriate test
because it has a vocabulary level of 3 to 5 years, which would
be far too easy and could overestimate José’s speech perception capabilities. The decision was made to test him with the
Western Ontario Plurals Test7 using a recorded picture-pointing
format (Table 18.2). The test assesses the ability of the child
to identify the presence of high-frequency stimuli (e.g., shoe
versus shoes).
Testing confirmed that José is having diculty hearing high
frequencies even though real-ear measures have indicated that
5
To validate
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Table 18.1 José’s aided narrowband noise thresholds
250 Hz 500 Hz 1000 Hz 2000 Hz 3000 Hz 4000 Hz 6000 Hz
Right HA (original settings) 20 dB 15 dB 20 dB 25 dB 35 dB 45 dB 50 dB
Left HA (original settings) 20 dB 10 dB 15 dB 25 dB 35 dB 45 dB 50 dB
Right HA (adjusted settings) 20 dB 15 dB 20 dB 20 dB 20 dB 25 dB 25 dB
Left HA (adjusted settings) 20 dB 10 dB 15 dB 20 dB 20 dB 20 dB 25 dB
José’s hearing aid settings are meeting targets. Validation of the
hearing aid fitting is critical if we want to know what a child is
actually hearing.
The audiologist adjusts the hearing aid settings to provide more
high-frequency gain (above recommended target). José is retested,
and results indicate both improved thresholds and improved
speech perception scores. The audiologist obtains uncomfortable
loudness thresholds (UCLs) with hearing aids, and José demonstrates no UCLs at softer-than-expected levels.
Childr
en speak what and how they hear. In José’s case, his
therapists had been working on the high-frequency sounds while
sitting very close to his ear, so he was familiar with high-frequency
consonants even though he did not hear them consistently.
Improvement in José’s auditory brain access resulted in immediate improvement in speech perception capabilities because he
as already familiar with the sounds. If he had not been familiar
w
with the consonants, even though aided thresholds would have
improved immediately, speech perception improvement would
have required additional auditory therapy.
18.4 Recommendations
Audiologic management is complex and involves more than
reporting test results. Audiologists are not technicians; we have
more responsibility than simply administering the tests. We
do need to determine the validity and reliability of the procedures, but that is not enough. Interpreting test results includes
estimating the child’s performance outside of the test situation
and making appropriate recommendations. That is, what are the
implications of the child’s sound room results on his real-world
speech-language, academic, literacy, and social-emotional performance? For example, if a child’s speech perception is poor at
a typical conversational level (50 dB HL/65 dB SPL), he will not
be able to understand people standing within 6 feet of him in a
quiet setting. If speech perception is poor at 35 dB HL (50 dB SPL),
he will not understand people more than 3 feet away and will
have diculty hearing in most classroom situations. While he
might hear what the teacher speaks into the remote microphone
(RM), he will not hear the comments of his classmates, and
missing them will significantly reduce his ability to participate
in classroom discussions and to learn from others.
18.4.1 Types of Recommendations
Diagnostic Recommendations
If testing indicates conductive hearing loss, we know we need to
refer for medical evaluation. If observations of the child suggest
Table 18.2 José’s speech perception test results
Right aid Left aid Binaural
50 dB HL (original settings) 56% 60% 60%
35 dB HL (original settings) 32%
50 dB HL + 5 SNR (original settings) 44%
50 dB HL (adjusted settings) 84% 76% 88%
35 dB HL (adjusted settings) 72%
50 dB HL + 5 SNR (adjusted settings) 76%
developmental concerns, referrals need to be made to appropriate practitioners (e.g., pediatrician, developmental pediatrician,
ediatric neurologist, speech-language pathologist, and physical
p
or occupational therapist).
Technology Recommendations
Technology evaluation should ensure that the child is hearing
soft speech throughout the frequency range in each ear. If not,
technology must be adjusted. Such adjustments might include
changing the settings of the current hearing aids in each ear,
changing to more powerful hearing aids, or considering cochlear
implantation. Almost every child will benefit from RM use outside of the classroom for after-school activities, travel in the car,
and dinnertime conversations. Therefore, a recommendation for
home use of an RM should be considered.
Speech/Language/Literacy Recommendations
If speech perception testing indicates anything less than excellent speech perception, even though technology is set to provide
optimal brain access, the child needs to be referred to the appropriate practitioner for auditory/linguistic skill development. If
the child is already in a therapy program, the practitioner should
be alerted to any speech perception problems observed and
documented by the audiologist.
Because a child’s academic and social success depends on
literacy skills, and literacy skills are based on auditory brain
development, audiologists should always include literacy recommendations in the report.8 Examples of literacy recommendations
include:
For an infant, read aloud 10 to 20 books per day.
•
For older children, continue to read aloud to them at least 30
•
minutes per day. Once children begin reading themselves,
we should continue to read to them, selecting books to read
aloud that are above their own reading level to expand word
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