噪声污染评估计算器
使用噪声污染评估计算器全面分析多个噪声源的叠加影响。计算综合分贝值和噪声传播范围，评估交通、工业和建筑噪声对周边环境和居民的影响程度。
Combined Sound Level
81.2 dB
Combined Sound Level vs Source 1 Level
公式
Combining Noise Sources
Sound levels in decibels are logarithmic, so you cannot simply add them. Two 80 dB sources produce 83 dB, not 160 dB.
Formula
Combined dB = 10 x log10(10^(L1/10) + 10^(L2/10))
OSHA Exposure Limit
Safe Hours = 8 / 2^((Combined dB - 90) / 5)
OSHA permits 8 hours at 90 dB, with halving for each 5 dB increase.
计算示例
Two machines produce 80 dB and 75 dB respectively.
- 0110^(80/10) = 100,000,000
- 0210^(75/10) = 31,622,776
- 03Sum = 131,622,776
- 04Combined = 10 x log10(131,622,776) = 81.2 dB
- 05Safe exposure = 8 / 2^((81.2 - 90)/5) = 8 / 2^(-1.76) = 27.1 hours
常见问题
Why can't I just add decibels?
Decibels are on a logarithmic scale. Adding two 80 dB sources gives 83 dB, not 160 dB. The logarithmic scale compresses huge pressure ranges into manageable numbers.
What noise levels are harmful?
Prolonged exposure above 85 dB causes hearing damage. Common sources: normal conversation (60 dB), lawn mower (90 dB), rock concert (110 dB), jet engine (140 dB).
What is the OSHA noise standard?
OSHA permits 8 hours of exposure at 90 dB, halving the allowed time for every 5 dB increase. At 95 dB, only 4 hours are permitted; at 100 dB, only 2 hours.