Is behavioral audiometry achievable in infants younger than 6 months of age?

Background and goalWhen carried out in addition to objective tests, behavioral audiometry performed in children with the so-called “Delaroche protocol” [IJORL 68 (2004) 1233-1243] enables to determine hearing thresholds by air and bone conduction over the whole auditory frequency range. In the present report, seventy-three hearing-impaired infants with different levels of motor and cognitive development were tested behaviorally before 6 months of age. Reliability of these early determined behavioral thresholds was then after analyzed using: (a) cross-sectional study, and (b) longitudinal study.MethodsCross-sectional study compared click-evoked ABR thresholds in the better ear with binaural high-frequency hearing thresholds. In longitudinal study, early measured binaural hearing thresholds from 500 through 4000 Hz were reassessed at 18 months.ResultsIn 13% of babies behavioral testing was not fully completed by 6 months of age. Nevertheless, both cross-sectional and longitudinal studies yielded intraclass correlation coefficients above 0.80, suggesting that behavioral testing is applicable to this very young population.ConclusionsAssessment of hearing after newborn screening should not be restricted to objective tests before 5½ months. It should also include bone- and air-conduction behavioral tests adjusted to developmental stage and performed in presence of parents.