Identification of Neonatal Hearing Impairment: Infants with Hearing Loss

OBJECTIVEThis article describes the audiologic findings and medical status of infants who were found to have hearing loss, detected as part of the Identification of Neonatal Hearing Impairment (INHI) project. In addition, the neonatal and maternal health variables for the group of infants who could not be tested with visual reinforcement audiometry (VRA) due to developmental and visual disability are presented. DESIGNThe overall goal of the INHI project was to evaluate the test performance of auditory brain stem response and evoked otoacoustic emission (OAE) tests given in the newborn period. These tools were evaluated on the basis of the infants’ hearing when tested behaviorally with VRA at 8 to 12 mo corrected age. The neonatal test results, VRA results, medical history information and a record of intercurrent events occurring between the neonatal period and the time of VRA were collated and reviewed. The purpose of this article is to review the characteristics of those infants who were found to have hearing loss. RESULTSOf 2995 infants who had VRA tests judged to be of good or fair reliability, 168 had a finding of hearing loss for at least one ear, an incidence of 5.6%. Si-ty-si- infants had bilateral losses, an incidence of 2%, and 22 infants had bilateral hearing losses in the moderate to profound range, an incidence 0.7%. The prevalence of middle ear problems was greater than 50% among these infants with hearing loss. From the larger group of 168 infants with hearing loss, a group of 56 infants (86 ears) was chosen as those with a low probability that the hearing loss was due to transient middle ear pathology and was more likely hearing loss of a permanent nature. These were the infants used for the analyses of neonatal test performance . In this selected group there were 30 infants with bilateral impairment of at least mild degree, which is an incidence of 1%. There were approximately equal numbers of ears in the mild, moderate, severe and profound range of hearing loss.Risk factors associated with hearing loss were reviewed for the total sample of infants tested with VRA and for those infants with hearing loss. A history of treatment with aminoglycosides was the risk factor most often reported in the entire sample; however, there was no difference in prevalence of this risk factor for the normal-hearing and hearing-impaired groups. The risk factor associated with the highest incidence of hearing loss was stigmata of syndromes associated with senso