Citation

Chan P, Ho K, Ryan AF. Mil. Med. 2016; 181(5 Suppl): 59-69.

Affiliation

UCSD School of Medicine and San Diego VA Medical Center, 9500 Gilman Drive, La Jolla, CA 92093.

Copyright

(Copyright © 2016, Association of Military Surgeons of the United States)

DOI

10.7205/MILMED-D-15-00139

PMID

27168554

Abstract

OBJECTIVES: The new Auditory 4.0 model has been developed for the assessment of auditory outcomes, expressed as temporary threshold shift (TTS) and permanent threshold shift (PTS), from exposures to impulse noise for unprotected ears, including the prediction of TTS recovery.

METHODS: Auditory 4.0 is an empirical model, constructed from test data collected from chinchillas exposed to impulse noise in the laboratory. Injury outcomes are defined as TTS and PTS, and Auditory 4.0 provides the full range of TTS and PTS dose-response curves with the risk factor constructed from A-weighted sound exposure level. Human data from large weapons noise exposure was also used to guide the development of the recovery model.

RESULTS: Guided by data, a 28-dBA shift was applied to the dose-response curves to account for the scaling from chinchillas to humans. Historical data from rifle noise tests were used to validate the dose-response curves. New chinchilla tests were performed to collect recovery data to construct the TTS recovery model.

CONCLUSIONS: Auditory 4.0 is the only model known to date that provides the full TTS and PTS dose-response curves, including a TTS recovery model. The model shows good agreement with historical data.

Reprint & Copyright © 2016 Association of Military Surgeons of the U.S.

Language: en