The relative importance of head size, gender and age on the auditory brainstem response.

Correlations between the ABR (auditory brainstem response) and subject characteristics of gender, age, and head diameter were established in simple and multiple regression analyses of normal hearing individuals. The simple regression tests demonstrated that head diameter and gender were significantly correlated with the latencies and amplitudes of waves I, III, and V and the I-V and III-V interpeak intervals. In nearly all cases, head diameter correlated more highly with the ABR waves than did gender. Males had longer latencies than females with comparable head diameter, suggesting that factors other than head size are differentiating them. Age was significantly correlated only with the latency of wave III. All significant subject variables also were compared simultaneously in a multiple regression analysis to determine their order of significance and relative contributions to the ABR wave latencies. This permitted the establishment of regression equations for each wave latency to predict the ABR with measurable subject characteristics.