Background Sound Levels in Rural Areas of the U.S.

ANSI S12.9 Part 3 Annex C provides a compilation of the average daytime, nighttime, and day-night sound levels in six land use categories, ranging from Category 1 - "very noisy urban residential" to Category 6 - "very quiet suburban and rural residential." However, the data in table C.1 of the standard, which provides typical day, night, and day-night sound levels by land use category, is based primarily on more urbanized areas, and provides caution in using the data for the less densely developed land use Categories 5 and 6. In this paper we supplement this Annex by providing a collection of ambient sound level data at over 150 rural locations primarily in the northeastern and midwestern U.S. As the ambient sound level is not a single metric, the results include the range of sound levels in various metrics, including the A-weighted L10, L50, L90, and Leq, for the daytime and nighttime, and DNL. Unweighted octave and 1/3 octave band ranges and averages are also presented for each metric. Where possible, we also compare these results at individual locations to the predictions made by national noise mapping programs.