Acoustic reflex thresholds: variability and distribution effects

Acoustic reflex thresholds (ARTs) at 500, 1000, and 2000 Hz from 1833 ears were subjected to multiple linear regression analyses using a stepwise inclusion model to determine the effects of hearing losses in the 500- to 4000-Hz range for each of the activators. Although statistically significant regression equations were developed, these accounted for only 1 to 47% of the variance of ART levels. In light of the wide variance of ARTs unexplainable directly from audiometric data, it was deemed more appropriate to consider the range of ARTs from the standpoint of the sampling distribution of ARTs as a function of hearing level. Deciles were calculated in the 10th through 90th percentile ranges. These data corroborate and expand upon previously reported material on the distributions of ARTs among ears with normal hearing and cochlear impairment.