Problems in the evaluation of hearing of infants

Abstract

Infant hearing loss should be identified early to prevent delays in the development of speech and language. However, evaluation of hearing of infants is not so easy, because training is required to estimate auidiometric thresholds from behavioral testing such as conditioned orientation response audiometry (COR). Most ENT physicians who are not capable of behavioral testing tend to evaluate hearing of infants only from testing auditory brainstem response (ABR). Information about the infant's auditory response to the environmental sounds could be obtained easily and might be a substitute for a behavioral testing. We administered a questionnaire to the parents to obtain accurate information about the infant's auditory response. Tanaka-Shindo's developmental battery test of auditory function is an established questionnaire with various questions about auditory response and development of speech according to the age of infants from 0-15month. We administered Tanaka-Shindo's questionnaire to the parents of infants before 8 months, and administered the following questionnaire to the parents of infants over 8 months. 1) If you call out the child's name from behind, does the child turn his/her head? 2) Does the child turn his/her head to any sounds on television, to any small sounds (for example: listened when someone opens the door or opens wrapping paper), or to beeping sounds from electric devices? To investigate the clinical usefulness of the questionnaire to estimate hearing in infants, 79 children (under 4y.o.) evaluated their hearing at the Tottori University Hospital were studied. Forty-three out of 45 (95. 6%) who had normal hearing had yes in the questionnaire, but the 18 who had moderate to severe (60dB∼) hearing loss did not have yes in the questionnaire. For the mentally retarded 33 children, 27 out of 29 (93%) who had normal hearing had yes in the questionnaire, but the 4 who had moderate to severe hearing loss did not have yes in the questionnaire. Questionnaire about the infant's auditory response is useful to differentiate between normal hearing and moderate to severe hearing loss. We recommend our questionnaire as screening procedure to most ENT physicians to identify hearing loss in infants. It is important refer patients not evaluated as normal to an ENT physician who is capable of diagnosing the hearing of infants by behavioral testing.