Noise Pollution Calculator
Assess noise exposure levels by combining multiple noise sources and comparing to health guidelines.
Combined Noise Level
70.4 dB
Combined Noise Level vs Primary Noise Source
公式
## How to Calculate Noise Pollution Noise levels are measured in decibels (dB) on a logarithmic scale. ### Combining Sources **Combined dB = 10 * log10(10^(dB1/10) + 10^(dB2/10))** ### Distance Attenuation **dB at distance = Source dB - 20 * log10(distance / reference)** ### Reference Levels - Whisper: 30 dB - Conversation: 60 dB - Traffic: 70-85 dB - Construction: 80-100 dB - WHO recommends daytime limit of 55-65 dB
计算示例
A 70 dB traffic noise and 60 dB HVAC system, 8 hours exposure at 50 feet.
- 01Combined: 10 * log10(10^7 + 10^6) = 10 * log10(11,000,000) = 70.4 dB
- 02At 50 ft: 70.4 - 20 * log10(50/3) = 70.4 - 24.4 = 46.0 dB
- 03vs WHO: 46.0 - 65 = -19.0 dB (below limit)
常见问题
What is a safe noise level?
The WHO recommends 55 dB for outdoor daytime and 40 dB for nighttime sleep. Occupational limits are 85 dB for 8 hours. Every 3 dB increase doubles the sound intensity.
How does noise affect health?
Chronic noise above 65 dB increases risk of cardiovascular disease, sleep disruption, stress, and cognitive impairment. The WHO estimates 1.6 million healthy life years are lost annually in Western Europe from traffic noise.
How is the decibel scale different from linear?
Decibels are logarithmic. A 10 dB increase sounds about twice as loud and represents 10x more sound intensity. Adding two equal sources increases the level by 3 dB, not double.