When is a firearm suppressor like a hearing protector?

High-level impulse noise exposure from small caliber firearms presents a significant risk of noise induced hearing loss (NIHL) for an unprotected ear. The most common method to reduce the level of noise is to provide hearing protection to both the shooter(s) and potential observers such as firing range instructors or bystanders. Not all hunters and shooters consistently use correctly fit hearing protection. Firearm suppressors provide an engineering noise control that can mitigate a significant portion of the NIHL risk. In this paper, potential analyses for the noise reduction of a firearm suppressor will be presented. The impulse insertion loss as a function of the measurement analysis time window for A-weighted, C-weighted, and unweighted sound pressure levels will be presented. This approach will be contrasted with the ANSI S12-42 standard for measuring impulse peak insertion loss for hearing protection devices.