Prevention of noise damages causes by shooting fire of Kalashnikov (AK-47) rifle by regulation of suitable distance

Abstract

The aims of this study were control of rifle shooting noise by regulation of suitable distance and investigation of frequency characteristic of the noise caused by single Kalashnikov rifle (AK-47) in an open shooting field. Due to the condition of the trainees and other people in the shooting fields, the measurements were done in 2 stages of individual and groups of 20 individuals and at 1, 30 and 50 meters distance, respectively. At each stage of the experiment the sound pressure level and peak sound pressure level were measured in C and A networks, and audio frequency analysis in octave centers of Z network was done simultaneously. The results of this study showed that the sound pressure level in network A in the stage of single shooter and group of 20 individuals were 102 and 110.4 dB respectively and in network C they were 102.9 and 112.5 dB, respectively. Also the peak of sound pressure level in network C at the stage of single shooter and group of 20 individuals were 130.30dB and 132.8 dB at the same distance (one meter) and in network A it was 130.3 and 142.4 dB, respectively. To prevent the damage cause by sound, we recommend increasing the distance between an individual and the sound source. Additionally, the complications in shooting fields can be reduced by increasing the distance more than 20 meters for single shooting and 50 meters for group shooting.