Temporary Threshold Shift from Gunshot Noise with Normal and Grazing Incidence

Abstract

Temporary threshold shifts (TTS) were measured following exposure to 4 rounds of gunfire (M-14), at 2-sec intervals, at a distance of 4 ft with incidence grazing or normal. Measured peak level was 168 dB; duration, 200 μsec. TTS was such as to suggest that daily exposure would produce permanent loss at high frequencies and, for normal incidence, possible loss at lower frequencies. Discrepancies between these findings and those of other investigators are discussed.