Audiological Follow-up Results after Newborn Hearing Screening Program

OBJECTIVES To investigate the validity of newborn hearing screening protocol using automated auditory brainstem response (AABR) with a confirmation method using click auditory brainstem response (ABR) and to evaluate changes in hearing status of infants with confirmed congenital hearing loss. METHODS Neonates in the well-baby nursery were screened by staged AABR. Subjects whose final AABR result was "refer" were tested by diagnostic click ABR and 226 Hz tympanometry within 3 months of age. Changes in hearing status of subjects with confirmed hearing loss were analyzed by follow-up ABR at 3-6 month intervals. RESULTS Of the 12,193 healthy babies born during this period, 10,879 (89.22%) were screened by AABR. Of 10,879 neonates screened by AABR, 148 (1.36%) were "referred"; of these, 45 subjects showed ABR thresholds over 30 dB nHL in at least one ear. Thirty-four subjects underwent serial follow-up ABR tests, with 11 (32.4%) found to have normal ABR thresholds. Most subjects with mild to moderate hearing loss were found to be normal before 1 year of age, whereas all infants with severe or profound hearing loss were identified as having congenital hearing loss. CONCLUSION The referral rate and the positive predictive value of our protocol were acceptable. We have also found here that substantial temporary hearing loss can be included in the first confirmative diagnosis. Temporary hearing loss of our study on follow-up give emphasis to need of further differentiation using the testing for bone conduction and middle ear status.