The Auditory Hazard Assessment Algorithm for Humans (AHAAH): Hazard Evaluation of Intense Sounds

Report No. ARL-TR-5587
Authors: G. Richard Price
Date/Pages: July 2011; 26 pages
Abstract: Prediction of hazard from intense sounds requires that predictive algorithms match the properties of the ear. The existing damage risk criteria do not and, as a result, perform badly. At the very high levels typical of gunfire, the ear has distinctive properties. The primary loss mechanism is mechanical stress within the cochlea. The conductive path exhibits spectral tuning, middle ear muscle attenuation of transmission, and peak limiting of stapes displacements. To deal with these issues, the AHAAH model was developed as a first-principles electroacoustic analog of the ear that matched these properties. It has been peer reviewed and shown to predict hazard to the human ear much more accurately than any other approach. It accommodates HPDs in the analysis, and its theoretical basis assures its generalizability to new impulses. It also has features which allow insight into engineering solutions to problems and promotes better HPD design and use. The model has been used internationally by the armaments community and the SAE, and it is being proposed as an ANSI standard for intense noise exposure. It is available for immediate use as a health hazard assessment tool and a design tool for the military.
Distribution: Approved for public release
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Last Update / Reviewed: July 1, 2011