抄録
Impulse noises from two types of firearms at shooting practice were measured in an indoor firing
range in Iruma air base, Japan Air Self-Defense Force. The peak sound pressure levels (SPLs) at the
point of shooters were 157.6 dB for the 9mm pistol and 165.1 dB for the type 64 rifle, respectively.
These values were almost as same as those reported before in an outdoor firing range, though the
reflected impulse noises were clearly observed in the indoor firing range. In the present study, we
also found that the SPLs at the point of coachers, placing close shooter, were 148.7 dB for the 9mm
pistol and 171.5 dB for the type 64 rifle, respectively. The ear protector(s) should be used at shooting
practice to attain better attenuation level against impulse noises, in order to prevent acoustic trauma.
