AFTE Store - Firearms Sound Levels and Measurements: An Impulse Sound Control Source for dB Measurements of Gunshots Part 1

The sound of gunshots is a common recollection of many witnesses at or near a shooting incident. On occasion, the sound of gunshots may be captured by various recording devices. Some witnesses even claim to be able to distinguish between certain types and calibers of firearms based on the quality and/or amplitude of these very short duration, high intensity sounds. For over a century firearms designers and manufacturers around the world have sought to minimize the sound levels of gunshots by various means, the most well known of which are so-called silencers, more properly called suppressors. A very limited number of decibel meters are capable of measuring the peak intensity of a firearm report. Such devices allow a means of comparing the intensity of gunshot sounds under a variety of conditions as well as evaluating the effectiveness of suppressors. Part 1 of this 3 part series will discuss the nature of gunshot sounds, the technology necessary to accurately measure the amplitude of such sounds, some representative examples generated by firearms frequently encountered in case work and suggested protocols for such measurements. Part 2 will evaluate and demonstrate the effects such things as muzzle pressure, muzzle velocity, microphone position, microphone standoff distance and environmental conditions on dB measurements of gunshots. Part 3 will compare a currently available dB meter with the unit employed in all of the author’s tests. Part 3 will also provide examples and comparisons of other high intensity impulse sounds to gunshots, the effectiveness of a variety of professionally made suppressors and one readily available suppressor found in every home.