A field survey on the annoyance caused by sounds from large firearms and road traffic

Subjective reactions to artillery sounds were determined for over 400 respondents divided among 17 different residential areas. Also, for the same respondents, the subjective effects of road-traffic sounds were determined enabling a comprehensive comparison of the dose-response relations. For the sake of comparison with other field surveys, the noise dose for the shooting sounds was, among other things, expressed as the yearly average C-weighted day-night level (CDNL) and that for the road-traffic sounds was expressed as the A-weighted day-night level (ADNL). Similarly, for both sound types the community response was expressed as the percentage of respondents being "highly annoyed." From the comparison of the two dose-response relationships it could be concluded that for numerically equal day-night levels, the artillery sounds were more annoying than the road-traffic sounds. Overall, the difference was equivalent to the change in annoyance produced by a 5-dB shift in the yearly average day-night levels of the sounds. With equal day-night levels for "downwind" conditions, the artillery and road-traffic sounds were equally annoying. Results from the present highly controlled field survey provided a new opportunity to optimize the parameter values in Schomer's rating procedure y = (1/beta)(LCE-PNSE) + PNSE, in which the noise exposure for impulsive sounds (y) is expressed as the A-weighted SEL of equally annoying vehicle sounds. PNSE represents the point at which the impulsive and vehicle sounds with numerically equal levels are also equally annoying. With PNSE fixed at 103 dB, an optimal solution was found with slope beta set to 1.3. With the previously recommended slope beta = 0.67, the rating sound level for artillery sounds would be underestimated by almost 12 dB.