Acoustic trauma from continuous noise: Minimum exposures, issues in clinical trial design, and comments on magnetic resonance imaging exposures

• Main Authors: Berger, E.H (Author), Dobie, R.A (Author)
• Format: Article
• Language: English
• Published: Acoustical Society of America 2019
• Subjects: Acoustic noise; Acoustic traumata; adverse event; Audio acoustics; Audio engineering; Audition; Civilian populations; clinical trial (topic); Clinical trial designs; Clinical Trials as Topic; Exposure limits; government; Hearing conservation program; Hearing Loss, Noise-Induced; human; Humans; Impulse noise; industrial noise; Magnetic resonance imaging; Magnetic Resonance Imaging; Medical applications; noise injury; Noise pollution; Noise, Occupational; nuclear magnetic resonance imaging; occupational exposure; Occupational Exposure; pathophysiology; Potential risks; practice guideline; Practice Guidelines as Topic; prevention and control; Temporary threshold shifts; United States; United States Occupational Safety and Health Administration
• Online Access: View Fulltext in Publisher

 Acoustic trauma (AT) is permanent hearing loss after a single noise exposure. A few human cases resulting from continuous, i.e., nonimpulsive noise, have been reported as reviewed by Ward [(1991). "Hearing loss from noise and music," presented at Audio Engineering Society, New York, October 4-8]. This paper updates that review by examining 11 cases in nine reports, from 1950 to 2006, with the intention of determining minimum exposures that may cause AT, including the potential risk of exposure to noise from magnetic resonance imaging machines. Diffuse-field related levels above 120 dBA for 10 s or more, or above 130 dBA for 2-3 s (values well above OSHA's unprotected exposure limits), can lead to AT. These cases appear to represent a susceptible fraction of the population, because much more intense exposures (e.g., 130 dBA for 32 min) have been tolerated by groups of volunteers who suffered only temporary threshold shifts. AT from continuous noise is unlikely to occur in OSHA-compliant hearing conservation programs, and probably rare enough in the general civilian population that clinical trials of drugs aimed at treating it are unlikely to be practical. AT from impulse noise, such as gunfire, which is specifically not the topic of the current work, is more amenable to clinical trials, especially in military settings. © 2019 Acoustical Society of America.