Types of Audiological Test Procedures
by Paula Schauer, M.S., CCC-A, and Joe Pillion, Ph.D.
Depending on the developmental level of your child, one of the following test procedures may be used to determine hearing ability.
This test is carried out by observing changes in a child's behavior and activity upon the presentation of test stimuli. Because behavioral changes may be subtle, two experienced examiners determine the presence or absence of a behavioral response. Examples of behavioral responses include: eye-shifts, eye-widening, cessation in activity, quieting, and startling.
This test is completed by conditioning a child to turn toward the stimulus and is reinforced by an animated toy which lights up. Responses consist of eye-shifts and/or head turns toward the sound source. In addition, localization skills may be evaluated to determine a child's ability to locate sounds from side-to-side.
To complete this type of evaluation, the child is conditioned to listen to auditory stimuli and respond to the sound by participating in a specific play activity (i.e., throwing a block in a bucket, placing pegs in a board, placing rings on a peg, etc.).
For this test procedure, the child is asked to raise a hand or to push a button in response to auditory stimuli.
There are three types of speech response testing that are used to determine the child's ability to respond to speech-like sounds or actually identify spoken words. Each procedure is described below.
Speech Awareness Threshold: This threshold is established by presenting speech-like sounds (b b b) and determining the child's ability to respond to those sounds at the lowest possible level through the use of BOA, VRA, AVRA, and, occasionally, CPA test procedures.
Speech Reception Threshold: This threshold is established by presenting one- or two-syllable words and having the child either identify a corresponding picture or object or repeat the word. The procedure is used to determine the lowest possible level at which the child is able to complete the task. This test procedure is generally used for VRA, CPA, and conventional audiometry.
Speech Recognition Testing: This test determines a child's ability to listen to one-syllable words at a normal conversation level or comfortable listening level and repeat the words accurately or point to a corresponding picture. This test is completed for children who are evaluated using CPA and conventional audiometry.
Tympanometry: This test determines the absence or presence of a middle ear problem (i.e., middle ear fluid or abnormality). In addition, it shows whether the ear canals are free from cerumen and whether pressure-equalization tubes are patent (free from blockage). This test is conducted on all patients who receive audiological evaluations and/or screenings.
Acoustic Reflex Thresholds: This test determines whether a muscle contraction occurs in the middle ear. The muscle contraction is elicited in the presence of loud sounds and serves as a protective device for the ear. When this test can be completed, it provides additional information about the absence or presence of a hearing impairment and assists in determining the type of impairment. Because it requires a child to remain still, the test may not be successfully completed for infants and young children.
This test evaluates the peripheral auditory status of children when one of the above test procedures indicates the presence of possible hearing impairment or if test results are inconclusive. Generally, the test is completed while the child is sedated (asleep). We place surface electrodes on the forehead, behind each ear, and on the crown of the head. A set of earphones is then placed on the child's ears and the electrodes record electrical activity generated by the brain in response to sound.
This test measures the degree of hearing ability in both ears, and is administered in conjunction with the other tests summarized above. AEP tests determine the degree and origin of hearing impairment in children who cannot or will not cooperate freely for behaviorally based test procedures. Integration of AEP results with other test findings permits auditory habilitative procedures (e.g., hearing aids) to be provided for infants and very young and/or developmentally delayed children.
The article above is reproduced from the Down Syndrome Guide disseminated by the Down Syndrome Clinic at Kennedy Krieger Institute. In accordance with federal copyright restrictions, the contents of this booklet may not be reproduced by photocopying or any other means without written permission from the copyright holder. © 1999 George Capone, M.D.
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