Not-so-normal hearing: Temporary hearing changes lead to chronic difficulties for listeners with "normal" audiometric thresholds.

Hearing loss has historically been mainly associated with elevated pure-tone thresholds. However, in recent years, there has been increased interest in addressing the hearing difficulties reported by individuals with normal hearing thresholds. In this study, we measured hearing thresholds, noise history, temporary threshold shift history, and hearing difficulty for a sample of 10,492 Service Members. Our data reveal that overall hearing difficulties increase systematically as a function of hearing threshold within the range that is conventionally considered to be "normal" hearing. Noise exposure history is associated with increasing hearing difficulty at all thresholds, particularly individuals with a history of noticeable changes in their hearing after noise exposure. These results challenge some fundamental assumptions of current hearing conservation programs and suggest that variations in post-noise hearing symptoms may reflect differences in individual susceptibility to permanent damage from noise exposure.