NCJ Number
19097
Journal
JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA Volume: 56 Issue: 5 Dated: (NOVEMBER 1974) Pages: 1515-1522
Date Published
1974
Length
8 pages
Annotation
IN AN EFFORT TO PROVIDE GUIDELINES FOR LAW ENFORCEMENT PERSONNEL TO PROTECT THEIR HEARING, THE PEAK PRESSURE LEVEL AND SIGNAL DURATION OF 8 POPULAR FIREARMS WERE MEASURED AND COMPARED TO 3 SETS OF GOVERNMENT STANDARDS.
Abstract
SMALL CONDENSER MICROPHONES AND A STORAGE OSCILLOSCOPE WERE USED TO RECORD THE BLAST WAVE SIGNATURES FROM A 9-MM AUTOMATIC, 0.357-CAL. MAGNUM REVOLVER, 0.41-CAL. MAGNUM REVOLVER, 0.22-CAL. REVOLVER, 0.45-CAL. AUTOMATIC, 0.44CAL. MAGNUM REVOLVER, 12-GAUGE SHOTGUN, AND 0.22-CAL. RIFLE. MEASUREMENTS WERE MADE AT THE EAR OF THE PERSON SHOOTING AND AT THE APPROXIMATE POSITION OF A NEIGHBOR AT A FIRING RANGE. SOME MEASUREMENTS WERE ALSO MADE AT A PRACTICE FIRING RANGE. A PORTABLE TAPE RECORDER WAS FOUND USEFUL FOR RECORDING GUN SIGNALS AND MEASURING DURATIONS. THE PEAK PRESSURE LEVELS OF THE SIGNATURES OF ALL THE FIREARMS TESTED EXCEED ONE STANDARD'S MAXIMUM OF 140 DECIBELS. IT WAS FOUND THAT IN AN ANECHOIC (NO REFLECTION OF SOUND WAVES) ENVIRONMENT THE NOISE FROM ALL THE FIREARMS EXCEPT THE .22 CALIBER RIFLE EXCEEDED EPA (ENVIRONMENTAL PROTECTION AGENCY) STANDARDS. AT A SOUND INSULATED FIRING RANGE, ALL OF THE FIREARMS TESTED EXCEEDED EPA REQUIREMENTS. (AUTHOR ABSTRACT MODIFIED)