Normative parameter characterization for the auditory brainstem response of the normal newborn Caracterizacion de los parametros normativos del potencial evocado auditivo del recien nacido normal.

The auditory brainstem response generated by clicks was studied in 119 normal newborns. One ear was studied in detail at 20, 40 and 60 dBnHL, the other at 20 and 30 dBnHL, increasing the intensity if no response was found. The latency for waves I, III and V in the detailed studied ear was 2.7 +/- .39, 5.4 +/- .44 and 7.7 +/- .48, respectively. 85% of newborns had thresholds for auditory brainstem response less than 40 dBnHL, 54% less than 20 dBnHL and 15% between 40 and 60 dBnHL. These findings are compatible with conductive loss in the higher threshold group and support data from Stockard, regarding high risk groups. Additionally, our data suggests that an adequate level to screen for hearing loss in newborns is between 30 and 40 dBnHL