Assessing Hearing of Deaf Children

The issue

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From the newborn hearing screening to transition to adulthood, deaf children and their parents are faced with frequent assessments.  Accurately and appropriately assessing the hearing of deaf children requires professionals who are knowledgeable and skilled in working with this diverse group of youngsters.  Professionals should be capable of effective and sensitive communication with parents and children, and families should feel comfortable taking an active role in the assessment and intervention of their deaf children.

What we know

Hearing tests for children vary based on the individual, the goal of the test, and the developmental age of the child. Screenings identify at-risk children and do not alone diagnose hearing loss.  A full diagnostic hearing test identifies or rules out hearing loss, identifies the type, degree, and configuration of the hearing loss, and helps determine the need for or course of intervention.  Hearing tests establish baselines and evaluate progress of intervention or therapy.  They assess everyday functional auditory skills and provide evidence for the use of hearing instruments or educational accommodations.

Assessing the hearing of children is not a single event but a process, and it may take several appointments for a full assessment.  Hearing assessment does not rely on any single test; rather, several tests typically are performed serving as cross-checks and assessing different aspects of hearing.  Physiologic tests measure the ear and brain’s responses to sound and do not require the child to participate beyond sitting still (which can be a big challenge!); whereas behavioral tests directly measure the child’s functional hearing, or what the child actually perceives, and require the child’s participation.  Full child and family histories are part of any audiological assessment.  Once a child is diagnosed with hearing loss, audiologists monitor the child’s hearing sensitivity at least every 6 to 12 months.

The diagnosis of hearing loss/ deafness in infants relies on physiologic measures, as infants are not able to reliably tell us what they can or cannot hear.  Auditory brainstem response (ABR) testing is the primary method of diagnosing hearing loss in this group.  In children younger than 6 months, the procedure can be administered while the infant is asleep.  Older infants and children must typically be given sedation or anesthesia to remain still for the testing.

Children who are 6 months of age or older can participate in behavioral hearing testing.  After age 5, this usually means raising a hand or pressing a button when a sound is heard.  For younger children, it involves some kind of conditioned response.  In Visual Reinforcement Audiometry (VRA), children are trained to look at a toy or movie when they hear a sound.  Children who are 30 months and older may complete Conditioned Play Audiometry (CPA), in which they perform a play-task when hearing a sound.  The validity and reliability of both VRA and CPA depend on appropriate conditioning and reinforcement from the tester and distinguishing between true and false responses.  Special methods may be used to condition deaf children, such as using a vibratory stimulus.

When testing the functional auditory skills and speech perception of children with severe to profound hearing loss, clinicians should choose test instruments at appropriate language and difficulty levels to elicit and demonstrate the child’s auditory strengths and areas for growth.  Speech perception is tested both with and without the child’s hearing devices (e.g., hearing aids, cochlear implants) to document their efficacy.  Diagnostic hearing assessments include word recognition tests, where the deaf child either speaks, signs, or writes words that s/he hears.  Intervention-oriented hearing tests may include basic auditory skills, sentence recognition, listening in noise, speechreading, parent/teacher/student report, and tests in the child’s actual classroom.

What we don’t know

ABR test results are used as proxy (stand-in) for hearing thresholds, but the functional hearing of a child is unknown until behavioral testing is completed.  Emerging evidence suggests that Auditory Steady State Response (ASSR) testing may supplement the ABR with more detail regarding deaf individuals’ residual hearing.  Some children may not complete behavioral hearing tests reliably and may require ABR.  Hearing tests provide evidence for intervention, but outcomes are not completely dependent upon test results.

Implications

Accurate hearing assessments of deaf children require skilled pediatric audiologists working in tandem with parents and children.  Procedures should be transparent to parents and also to children as they age.  Deaf children may require different test procedures or instruments than other children with lesser hearing losses.  Pediatric audiology remains a critical shortage area in many locales, creating additional obstacles to obtaining appropriate and timely assessment.

Posted on April 1, 2015 by
Elizabeth Jackson Machmer
National Technical Institute for the Deaf
Rochester Institute of Technology
ejmerp {at} rit.edu

Further reading

Moeller, M. P., Carr, G., Seaver, L., Stredler-Brown, A., & Holzinger, D. (2013). Best practices in family-centered early intervention for children who are deaf or hard of hearing: An international consensus statement. Journal of Deaf Studies and Deaf Education, 18, 429-445. view detailsYoshinaga-Itano, C. (2013). Principles and guidelines for early intervention after confirmation that a child is deaf or hard of hearing. Advance online publication. Journal of Deaf Studies and Deaf Education, 19, 143-175. view details