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5. Environmental A nalysir <br />NOISE <br />Because community receptors are more sensitive to unwanted noise intrusion at night, state law requires uire that, for planning purposes, n artificial dB increment be added to quiet - time noise levels <br />in a 4 -hour noise <br />descriptor called the Community Noise Equivalent Level NEL) or Day -Might Noise Level (Loo). <br />Psychological and Physiological Effects of Noise <br />Physical damage to human hearing begins at prolonged exposure to noise levels higher than 85 dBA. <br />Exposure to high noise levels affects the entire biological system, with prolonged noise exposure in excess <br />of 75 dBA increasing body tensions, thereby affecting Mood pressure and functions of the heart and nervous <br />system. Extended periods of noise exposure above 90 dBA can result in permanent cell damage. when the <br />noise level reaches 120 dBA, a tickling sensation occurs in the human ear even with short - terra exposure. <br />This level of noise is called the threshold of feeling. As the sound reaches 140 dBA, the tickling sensation is <br />replaced by the feeling of pain in the ear, called the threshold of pain. A sound level of 160 to 165 dBA will <br />result in dizziness or loss of equilibrium. The ambient or background noise problem is widespread and <br />generally more concentrated in urban areas than in outlying, less developed areas. Table 5.2-2 shoves <br />Typical Noise Levels from Noise Sources. <br />Table 5.2-2 <br />Typkal Noise Levels from Noise Sources <br />Nose Level <br />Comm on Outdoor Activities ffBA) Common <br />Indoor Activities <br />Source: California Department of Transportation, Technical Noise Su p�ement to the Traffic Noise Analysis Protocol, Table 9- 2138.2, October 1 998. <br />FalrhavenlLincoln and Santa ClaralLincoln Intersection Mo i icat o rj City of Santa Aria • Page 5.2 -3 <br />Stipplement to the Santa Ana Second Main Track Project EIR Resolution No. 2009 -034 <br />Page 69 of 130 <br />110 <br />Rack Sand <br />ROB <br />.het Flyover at 1,000 feet <br />100 <br />Gas Lawn Mower at three feet <br />0 <br />Diesel Truck at 50 feet, at 50 mph <br />Food Blender at three feet <br />80 <br />Garbage Disposal at three feet <br />Nois Urban Area, Da 'nee <br />70 <br />Vacuum Cleaner at ten feet <br />Commercial Area <br />Normal Speech at three feet <br />Heavy Traffic at 300 feet <br />60 <br />Large Business Office <br />Quiet Utarn Daytime <br />50 <br />Dishwasher Next Room <br />Quiet Urban Nighttime <br />40 <br />Theater, Large Conference Room background <br />Quiet suburban lvli httme <br />0 <br />Library <br />Quiet Rural Nighttime <br />Bedroom at Night Concert Fall (background) <br />0 <br />BroadeasVRecording Studio <br />10 <br />Lowest Threshold of Human Heading <br />0 <br />Lowest Threshold of Human Hearina <br />Source: California Department of Transportation, Technical Noise Su p�ement to the Traffic Noise Analysis Protocol, Table 9- 2138.2, October 1 998. <br />FalrhavenlLincoln and Santa ClaralLincoln Intersection Mo i icat o rj City of Santa Aria • Page 5.2 -3 <br />Stipplement to the Santa Ana Second Main Track Project EIR Resolution No. 2009 -034 <br />Page 69 of 130 <br />