BACKGROUND: In a 2-stage neonatal hearing screening protocol, if an infant fails the first-stage screening with an otoacoustic emissions test, an automated auditory brainstem response (ABR) test is performed. The purpose of this study was to estimate the rate of hearing loss detected by first-stage otoacoustic emissions test but missed by second-stage automated ABR testing. METHODS: The data of 17 078 infants who were born at Lis Maternity Hospital between January 2013 and June 2014 were reviewed. Infants who failed screening with a transient evoked otoacoustic emissions (TEOAE) test and infants admitted to the NICU for more than 5 days underwent screening with an automated ABR test at 45 decibel hearing level (dB HL). All infants who failed screening with TEOAE were referred to a follow-up evaluation at the hearing clinic. RESULTS: Twenty-four percent of the infants who failed the TEOAE and passed the automated ABR hearing screening tests were eventually diagnosed with hearing loss by diagnostic ABR testing (22/90). They comprised 52% of all of the infants in the birth cohort who were diagnosed with permanent or persistent hearing loss >25 dB HL in 1 or both ears (22/42). Hearing loss >45 dB HL, which is considered to be in the range of moderate to profound severity, was diagnosed in 36% of the infants in this group (8/22), comprising 42% of the infants with hearing loss of this degree (8/19). CONCLUSIONS: The sensitivity of the diverse response detection methods of automated ABR devices needs to be further empirically evaluated.