Detection and Localization of Magazine Insertion Clicks in Various Environmental Noises

The early detection and accurate localization of threatening sounds is vital for the survival of military personnel. The purpose of the present study was to investigate the detection, localization, and response time to an M-16 rifle magazine insertion click in three background conditions: jungle, pink, and ambient noise. The level of the click varied from -18 to 0 dB signal-to-noise ratio (SNR). Reported results indicate that detection rates of 50, 70, and 100% required SNRs of ?6 to ?12, ?3, and 0 dB, respectively. Localization accuracy of 50 and 80% within a ±15° angle required SNRs of about ?6 and 0 dB, respectively; 100% accuracy was never achieved. Response time was about 2.0–2.5 s for high SNRs but increased gradually at poorer SNRs. The military relevance of the reported findings is discussed.