Noise Assessment at the Area near Military Shooting Range

Abstract

Noise is defined as any unwanted sound that can induce stress and annoyance. As the democracy is being more mature and the quality of life is rapidly increasing in Korea, the military noise problem has augmented civil complaints and lawsuits. Previous studies for military noise were mostly focused on military aircraft and psychological symptoms. Moreover, most studies did not consider frequency distribution and propagation factors in their analysis. The purpose of this study was to find factors affecting the military noise by measuring the levels of noise during shooting and identify the characteristics of shooting noise using mapping and frequency analyzing.Total 15 homes in two village and 30 points near the Air-force camp were selected for the measurement of noise levels in Boryeong city of Chungnam. The levels of cumulative noise were measured using dosimeters for both home outdoor and indoor on the shooting day. The levels of noise at the 30 points were measured using sound pressure level meters 3 times for 5 minutes each. The sound level meter applied 1/3 octave filter was used to confirm the frequency distribution. The Blaze software was used to download data and to calculate equivalent noise level (Leq). Independent t-test, spearman correlation, and multiple regression analysis were preformed to indentify factors affecting the noise using SPSS 18. The noise map was created by Surfer 8 with geographical information and noise level. Leqs between shooting day and non-shooting day were 56.4 ± 3.7 dBA and 48.5 ± 2.9 dBA, respectively (p < 0.0001). Noise levels of Vulcan were higher than those of Patriot during shooting: maximum levels of Leq were 98.0 dBA for Vulcan and 84.4 dBA for Patriot, maximum levels of Lpeak were 125.2 dBA and 113.7 dBA, respectively. The analysis of outdoor noise level showed that Leq had positive correlations between shooting time (r = 0.53, p < 0.01) and shooting number (r = 0.47, p < 0.01) and negative correlation between humidity (r = - 0.55, p < 0.01) and distance (r = - 0.50, p < 0.01). In the results of multiple analysis, it was found that types of firearm significantly affected the noise level (β = 3.786, p < 0.0001). The Vulcan missile generated more noise than the Patriot missile. The noise map showed that most locations near the military camp were noise exposed exceeding 50 dBA, and the maximum value was 77.0 dBA during the shooting.During shooting day, the noise level of Vulcan were higher than Patriot, it exceeded the Korea standard. This suggests that some improvements are needed to reduce the noise level by adjusting the shooting frequency and constructing soundproof walls. In addition, the isolation of noise sources by relocating the military camp or residence provides another solution.