The practice of pediatric audiology is an art and a science. Engaging young children to achieve accurate and comprehensive results requires a strong foundation of technique (science), creativity (art), and flexibility.
In August 2012, a panel of experts in pediatric audiological assessment, led by Wende Yellin, PhD, published the American Academy of Audiology’s Audiological Guideline for the Assessment of Hearing in Infants and Young Children. Over the past several months,pediatric audiologists from across the country reviewed this document and the literature in our field of specialty, to update the 2012 document.
The revised guidance document followed the process laid out by the Academy and went through select peer review, as well as a 30-day member-comment period. The result of this collaborative work is now available on the Academy website (www.audiology.org/publications-resources/document-library/infant-identif...).
There were no substantial changes recommended for the Otoacoustic Emissions and Electrophysiology (ABR and ASSR) sections based on reviews of current literature. Highlights of changes to the General Procedure, Pediatric Audiometry, and Acoustic Immittance sections are to follow.
The 2007 Joint Committee on Infant Hearing (JCIH) 1-3-6 guidelines recommend hearing screening by one month of age, diagnosis of hearing loss by three months of age, and enrollment in early intervention by six months of age (JCIH, 2007).
For those states meeting these benchmarks, the 2019 JCIH position statement (which was published just before the updated guideline was submitted for member review) encourages reduction of the timelines to 1-2-3 (JCIH, 2019). The previous Academy guideline recommended that, for any infant under the age of three years for whom hearing aids and/or cochlear implant(s) are to be fitted or recommended, at least one electrophysiological measure of threshold prediction should be completed (JCIH, 2007).
This recommendation was broadened in scope to include any infant or young child for whom complete reliable behavioral results cannot be obtained or replicated. Electrophysiological measures of threshold prediction should be completed for these patients as well, and not just those who are suspected to have hearing loss.
To further support the new recommendations by JCIH and in an effort to reduce “lost to follow-up/documentation,” it is recommended that, when a child under three years of age is identified with hearing loss, not only is an immediate referral made to the Part C provider with a goal of referral within 48 hours (JCIH, 2019), but also that all diagnostic results should be reported to the state Early Hearing Detection and Identification (EHDI) Program (e.g., state Department of Health).
Due to the increased awareness and focus on prevention of noise-induced hearing loss in children, within case history, it is recommended that the clinician ask about behaviors that may put a child at risk for noise-induced hearing loss so that appropriate assessment and treatment, including counseling, can be implemented.
Given the lack of evidence supporting “behavioral observation” as a clinical protocol, methods typically used for this were removed from the guideline. However, observation of behavioral responses to auditory stimuli may contribute to the global assessment of auditory-skill development. Use of tools that systematically document behavioral responses to auditory stimuli (e.g., Early Listening Function, Functional Auditory Performance Indicators, LittlEARs) is encouraged.
Documentation of observed behaviors (e.g., cessation of activity, eye-widening) in response to calibrated stimuli, if observed, should be recorded as minimum response levels. These responses should be interpreted with caution and may be reported to supplement information obtained using physiologic measures (e.g., auditory brainstem response, otoacoustic emissions, and immittance measures).
Given the clinical importance of determining perception/recognition for speech stimuli beyond simple detection, detailed procedures for speech perception/word recognition are provided in the updated guideline. In addition, tables are provided for appropriate closed- and open-set test materials. Guidelines for determining which materials are developmentally appropriate are included, adapted from the Pediatric Minimal Speech Test Battery tutorial (Uhler et al, 2017).
Tympanometry guidelines were expanded regarding age and probe tone. The most recent JCIH Position Statement (2019) recommended use of the 1000 Hz probe tone for infants up to nine months of age based on a 2013 study by Hoffman et al, which found greater sensitivity and specificity for the 1000 Hz probe tone in 0 to 3 months, 3 to 6 months, and 6 to 9 months.
For 9- to 12-month-olds, there was greater sensitivity and specificity for the 226 Hz probe tone. Use of both the 1000 Hz and 226 Hz probe tone may be considered for use with infants between 6 and 9 months of age. Use of a 1000 Hz probe tone may also be considered for use with other populations, such as patients with Trisomy 21.
Heeren (2013) found that the 226 Hz tympanogram is not an accurate predictor of middle-ear status in the Trisomy 21 population, as poor specificity of the 226 Hz tympanogram shows that the tympanogram may be over-diagnosing abnormalities of the middle-ear space, when in fact, there are none.
This information is critical due to difficulty visualizing the tympanic membrane of children with Trisomy 21. Due to joint laxity, small ear canal size, anterior tympanic membrane orientation, and softer tissue composition, a 1000 Hz probe tone may have greater reliability in patients with Trisomy 21 (Lewis et al, 2011).
Wideband acoustic immittance is an area of interest as a clinical tool to evaluate middle-ear status in infants and young children. Some studies have demonstrated useful applications in identifying those with middle-ear abnormalities. However, further investigation, including development of age-based norms, is needed (Hunter et al, 2013).
Acoustic reflexes should minimally be performed at 1000 Hz and other stimulus frequencies as desired, or for broadband noise when a 226 Hz probe tone is used. Testing at 4000 Hz may be omitted in favor of testing at other frequencies, as it is sometimes absent in those with normal hearing and does not provide any additional diagnostic information (Hunter, 2013).
If testing is completed using a 1000 Hz probe tone, a 1000 Hz eliciting tone should not be used due to the potential for interaction between the probe and eliciting tones and possibility of artifact (Smith and Wolfe, 2013).
A repeatable, observable decrease in admittance timed with the stimulus should occur; the lowest intensity with a repeatable admittance decrease is defined as the acoustic reflex threshold.
Of note, acoustic reflexes in infants may differ from those observed in older children and adults (Gerber et al, 1984). An upward deflection may be observed, as opposed to the typical downward decrease in admittance that we are accustomed to seeing (Smith and Wolfe, 2013). A table for interpretation of Acoustic Middle-Ear Muscle Reflex Responses was added.
Use of evidence-based practice guidelines is critical to provide high-quality consistent care to our patients. The Academy’s 2012 Audiological Guideline for the Assessment of Hearing in Infants and Young Children has been an invaluable resource for clinical practice with our youngest patients.
On behalf of the audiologists tasked with the 2019 update and all who provided input into the document, we would like to express our gratitude to the 2012 team who developed a comprehensive, clinically applicable guideline.