Английская Википедия:Day–evening–night noise level
The day–evening–night noise level or LШаблон:Sub is a 2002 European standard to express noise level over an entire day. It imposes a penalty on sound levels during evening and night[1] and it is primarily used for noise assessments of airports, busy main roads, main railway lines and in cities over 100,000 residents.[2][3][4] The penalty for sound production during evenings and nights is due to higher nuisance perception during quieter hours and to prevent sleep deprivation for nearby residents.
Definition
LШаблон:Sub is calculated as:[5]
<math>L_{den} = 10 \cdot log_{10} \left(\frac{1}{24} \left(12\cdot 10 ^ \frac{L_{day}}{10} + 4\cdot 10 ^\frac{L_{evening} + 5}{10} + 8\cdot 10 ^\frac{L_{night} + 10}{10}\right)\right)</math>
Where the long-term average noise levels are defined as:
| Part of the day | hours | penalty (dB) |
|---|---|---|
| day | 07:00 - 19:00 | 0 |
| evening | 19:00 - 23:00 | 5 |
| night | 23:00 - 07:00 | 10 |
The exact hours of the three periods may be chosen differently by individual EU member states.
The formula for LШаблон:Sub can be considered a weighted average of the yearly individual noise level during day, evening and night.
See also
- Environmental noise directive
- Day-night average sound level, the US equivalent
References
