Audiology and Speech-Language Sciences, University of Northern Colorado, Greeley, Colorado 80639, USA.
Int J Audiol. 2013 Feb;52 Suppl 1(0 1):S9-19. doi: 10.3109/14992027.2012.745650.
This study describes signals generated by .22 and .32 caliber starter pistols in the context of noise-induced hearing loss risk for sports officials and athletes.
Acoustic comparison of impulses generated from typical .22 and .32 caliber starter pistols firing blanks were made to impulses generated from comparable firearms firing both blanks and live rounds. Acoustic characteristics are described in terms of directionality and distance from the shooter in a simulated outdoor running track. Metrics include peak sound pressure levels (SPL), A-weighted equivalent 8-hour level (L(eqA8)), and maximum permissible number of individual shots, or maximum permissible exposures (MPE) for the unprotected ear.
Starter pistols produce peak SPLs above 140 dB. The numbers of MPEs are as few as five for the .22-caliber starter pistol, and somewhat higher (≤ 25) for the .32-caliber pistol.
The impulsive sounds produced by starter pistols correspond to MPE numbers that are unacceptably small for unprotected officials and others in the immediate vicinity of the shooter. At the distances included in this study, the risk to athletes appears to be low (when referencing exposure criteria for adults), but the sound associated with the starter pistol will contribute to the athlete's overall noise exposure.
本研究描述了.22 和.32 口径发令枪在运动官员和运动员的噪声性听力损失风险背景下产生的信号。
对典型的.22 和.32 口径发令枪发射空包弹产生的脉冲与可比枪支发射空包弹和实弹产生的脉冲进行声学比较。声学特性是根据模拟户外跑道上的射击者的方向和距离来描述的。指标包括峰值声压级(SPL)、A 加权等效 8 小时水平(L(eqA8))和最大允许单个射击次数,或未受保护耳朵的最大允许暴露次数(MPE)。
发令枪产生的峰值 SPL 超过 140dB。对于.22 口径的发令枪,MPE 的数量少至五个,对于.32 口径的发令枪,数量略高(≤25)。
发令枪产生的脉冲声与 MPE 数量相对应,对于未受保护的官员和射击者附近的其他人来说,这些数量太小,无法接受。在本研究包含的距离内,运动员的风险似乎较低(当参考成人的暴露标准时),但发令枪发出的声音将增加运动员的整体噪声暴露。