Evaluation of impulse noise criteria using human volunteer data

TLDR

The study evaluates four NATO impulse noise auditory injury criteria—MIL‑STD‑1474D, Pfander, Smoorenburg, and L(Aeq8)—using human volunteer data. Data were collected from volunteers wearing single‑hearing protection exposed to increasing blast overpressure, and logistic regression was used to correlate each criterion with the test data. All four criteria were found to be overly conservative by 9.6–21.2 dB, with MIL‑STD‑1474D underestimating the 95 % injury threshold by 9.6 dB, and similar conservatism observed for the other three criteria.

Abstract

Four impulse noise auditory injury criteria adopted by NATO countries, namely, the MIL-STD-1474D (USA), Pfander (Germany), Smoorenburg (Netherlands), and L(Aeq8) (France), are evaluated against human volunteer data. Data from subjects wearing single-hearing protection exposed to increasing blast overpressure effects were obtained from tests sponsored by the US Army Medical Research and Material Command. Using logistic regression, the four criteria were each correlated with the test data. The analysis shows that all four criteria are overly conservative by 9.6-21.2 dB for the subjects as tested. The MIL-STD-1474D for single-hearing protection is 9.6 dB lower than the observed injury threshold for 95% protection with 95% confidence for this particular group of subjects as tested. Similar conclusions can be drawn for the other three criteria.