c . Normal permanent construction can be expected to provide an NLR of 20 dB , thus the reduction requirements are often stated as 5 , 10 , or 15 dB o normally assume mechanical ventilation , upgraded sound transmission class ratings in windows and doors , and closed windows year round . Additio given to modifying NLR levels based on peak noise levels or vibrations .
d . NLR criteria will not eliminate outdoor noise problems . However , building location , site planning , design , and use of berms and barriers can help m particularly from ground level sources . Measures that reduce noise at a site should be used wherever practical in preference to measures that only p
2 . Measures to achieve NLR of 25 dB must be incorporated into the design and construction of portions of these buildings where the public is receive areas , or where the normal noise level is low .
3 . Measures to achieve NLR of 30 dB must be incorporated into the design and construction of portions of these buildings where the public is receive areas , or where the normal noise level is low .
4 . Measures to achieve NLR of 35 dB must be incorporated into the design and construction of portions of these buildings where the public is receive areas , or where the normal noise level is low .
5 . If project or proposed development is noise sensitive , use indicated NLR ; if not , land use is compatible without NLR . 6 . Buildings are not permitted . 7 . Land use is compatible provided special sound reinforcement systems are installed . 8 . Residential buildings require an NLR of 25 dB . 9 . Residential buildings require an NLR of 30 dB . 10 . Residential buildings are not permitted .
11 . Land use that involves outdoor activities is not recommended , but if the community allows such activities , hearing protection devices should be w present . Long‐term exposure ( multiple hours per day over many years ) to high noise levels can cause hearing loss in some unprotected individuals .
Source : Air Force Instruction AFI32‐7063 , Rev . December 2015 .
June 2017 Background Report