2022 NHCA Annual Virtual Conference

Traditional hearing conservation programs are based on the assumption that individuals who do not experience permanent threshold shifts do not experience long-term damage from noise exposure. However, previous data from animal models suggest that temporary threshold shifts (TTS) can cause permanent damage that may not be detectable with pure tone audiometric thresholds. In the current study, 10,000 Service Members (SM) were asked to report how frequently they experienced changes in hearing (dull or muffled sound) after exposure to a loud noise and the longest amount of time these symptoms persisted after a noise exposure. Roughly 35% of SMs reported that they never experienced TTS symptoms, and this group outperformed all others on a variety of subjective and objective measures of hearing health. Slight but significant decreases in these measures were found for individuals reporting TTS once or a few times in their lifetime. The measures were substantially degraded for approximately 10% of SMs who reported experiencing TTS once per year or more. Here we discuss the implications that self-reported TTS may have as an indicator of hearing damage for individuals in hearing conservation programs with normal hearing thresholds.