Acoustical Signature of Some Hand Guns Commonly Employed in Law Enforcement

Abstract

Small condenser microphones and a storage oscilloscope were used to record the N-wave signatures from a 9-mm Ruger, 0.357 magnum, 0.41 magnum, 0.22 long rifle, 0.44 magnum, 12-gauge shotgun, and 0.22 rifle. Measurements were made at the ear of the person shooting and at the approximate position of a neighbor at a firing range. Data on peak SPL and durations (A and B durations) are given, as well as data obtained at a practice firing range. The results are discussed from the point of view of using ear defenders to protect against temporary and permanent threshold shift incurred during practice. [Research supported by the National Institute of Law Enforcement and Criminal Justice.]