Anomalous screening outcomes from click-evoked otoacoustic emissions and auditory brainstem response tests

Transiently evoked otoacoustic emissions (TEOAE) and auditory brainstem res ponse (ABR) tests were used in parallel to screen 862 neonates with risk fa ctors for hearing loss. Seven neonates (0.81%) passed on TEOAE screen yet f ailed on ABR in one ear (six neonates) or both ears (one neonate). This com bination of results has been termed 'anomalous'. Examination of audiometric results obtained on follow-up shows that in one ear of one neonate the res ult was consistent with the later confirmed audiogram shape. The explanatio n for the anomalous results in the remaining ears is unclear although neura l maturation and the effects of hyperbilirubinaemia are possibilities. Ther e were no instances of progressive or retrocochlear hearing loss identified . None of the seven neonates had better ear hearing loss of greater than or equal to 40 dB on long term follow-up.