Agenda - 11-22-2004-c1 - Laserfiche WebLink

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_.. ,_ 21 Attachment 3 Environmental Sound 5 ~_ :C iE Page 6 Timarn tnwax y rarcra: a~roarzxs~ti^ rn~i3~ nra n au~Et'sueu~ri~,ta srtz4~ Wlale no perfectmeasurehas been developed, the day-night levelis the best available single- number rafing for the long term acoustical "climate" ofa community, The range ofday-night levels in American residential communities is wide. In some wilderness and farm areas it can be below 35 dBA.. However, it is often closer to 45 dBA due to insects, animals, and farm activities. Most residential areas are in the range of 50 to 60 dBA.. The day-night level can be as high as 85 dBA at some places in very densely populated parts oflarge cities. The EPA published data in 1974 relating typical day-night sound levels to population density. The data also showed the percentage ofthe nationalurban population exposed to the various levels, The table below is a listing of this data extended to rural areas, Some places can be noisier than expected based on the population density alone, This can easily happen around airports and near major highways, For population densities of 6300 people per square mile and higher, there is usually very little provision for outdoor activities. People in these more populous areas aze more likely to live mostly indoors. They use protected localparks or travelto recreationalareas in the country for outdoor activities, In quieter, low-density areas there are single-family homes with lazge yards. People expect to enjoy outdoor activities in their own yards. Thus, there is a difference between "indoor communities" that accept more noise and "outdoor communities."