TO TIRE-ROAD NOISE Sponsored by American Concrete Pavement Association

Summary Methods used to quantify annoyance due to environmental noise are described as well as the results of an analysis of vehicle passby recordings. Most methods currently used to quantify the impact of noise are based on average or maximum A-weighted sound pressure levels. It is known that the loudness of a sound is the primary driver in annoyance; however, it is also known that other sound characteristics, such as the presence of tones, fluctuations, spectral balance and impulsiveness, also impact annoyance. While A-weighted sound pressure levels may be strongly correlated to loudness levels for some sets of sounds, the relationship between the two can change if the characteristics of the sounds in the set change. Recently developed models of loudness incorporate many characteristics of the human hearing system including changes in response behavior with increased level, frequency masking and temporal masking. The A-weighting is derived from the 40 phon equal loudness contour and is only truly appropriate for analysis of relatively quiet sounds. In contrast, the loudness models are appropriate for sounds over a wide range of levels and incorporate the chang