Ninety percent of all newborns in the United States are now screening for hearing loss before they leave the hospital. Many hospitals use a 2-stage protocol for newborn hearing screening in which all infants are screened first with otoacoustic emissions (OEA). No additional testing is done with infants who pass the OAE, but infants who fail the OAE next are screened with automated auditory brainstem response (A-ABR). Infants who fail the A-ABR screening are referred for diagnostic testing to determine whether they have permanent hearing loss (PHL). Those who pass the A-ABR are considered at low risk for hearing loss and are not tested further. The objective of this multicenter study was to determine whether a substantial number of infants who fail the initial OAE and pass the A-ABR have PHL ~ 9 months of age.
Seven birthing centers with successful newborn hearing screening programs using a 2-stage OAE/A-ABR screening protocol participated. During the study period, 86,634 infants were screened for hearing loss at these sites. Of those infants who failed the OAE but passed the A-ABR, in at least 1 ear, 1,524 were enrolled in the study. Data about prenatal, neonatal, and socio-economic factors, plus hearing loss risk indicators, were collected for all enrolled infants. When the infants were an average of 9.7 months of age, diagnostic audiologic evaluations were done for 64% of the enrolled infants (1,432 ears from 973 infants).
Twenty-one infants (30 ears) who had failed the OAE but passed the A-ABR during the newborn hearing screening were identified with permanent bilateral or unilateral hearing loss. Twenty-three (77%) of the ears had mild hearing loss (average of 1 kHz, 2kHZ, and 4 kHz. < 40-decibel hearing level). Nine (43%) of infants had bilateral as opposed to unilateral loss, and 18 (86%) infants had sensorineural as opposed to permanent conductive hearing loss.
If all infants were screened for hearing loss using the 2-stage OAE/A-ABR newborn hearing screening protocol currently used in many hospitals, then ~ 23% of those with PHL at ~ 9 months of age would have passed the A-ABR. This happens in part because much of the A-ABR screening equipment in current use was designed to identify infants with moderate or greater hearing loss. Thus, program administrators should be certain that the screening program, equipment, and protocols are designed to identify the type of hearing loss targeted by their programs. The results also show the need for continued surveillance of hearing status during childhood.
The following articles were published describing the results of the study. The results of the study were presented to multiple international, national, and local audiences. Those presentations are listed.