Susceptibility to intense impulse noise: Evidence from the Albuquerque dataset.

Abstract

For theoretical and applied reasons, there has long been an interest in the problem of susceptibility to hearing loss from intense sounds; yet no useful predictive indices have been found. Some evidence suggests that susceptibility cannot be considered as a constant for individual ears; however, thinking and experimental designs often assume that it is. A critical data set in this regard are the US Army’s Albuquerque studies [Johnson, D. L. (1994) USAARL Contract Report No. 94‐2, U.S. Army Aeromedical Research Laboratory, Rucker, AL] in which human Ss were exposed repeatedly to explosive sources. An analysis of individual threshold shift data finds that of 28 instances in which ears showed a threshold shift 15 dB or higher, 25 Ss subsequently passed higher levels of exposure, sometimes much higher levels. This outcome was clearly contrary to the expectation that they were susceptible ears. Issues such as HPD fit and random elements in exposures are demonstrably a part of the problem. Susceptibility, at present, should probably be considered a statistical concept, appropriate to groups of Ss.