噪声污染计算器

使用噪声污染计算器评估环境噪声对健康和生态的影响水平。输入噪声源参数和距离，计算分贝衰减和暴露等级，判断是否超过安全标准限值。

Primary Noise Source

Secondary Noise Source

Daily Exposure Hours

hours

Distance from Source

feet

Combined Noise Level

70.4 dB

Level at Distance46.0 dB

vs WHO Limit (65 dB)-19.0 dB above/below

Safe Exposure at This Level65,885.9 hours

Combined Noise Level vs Primary Noise Source

查看公式 →

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.