Noise limits are established as excessive noise exposure can have adverse effects on health. The most well known impact is hearing loss caused by consistently high sound levels. However, noise can also lead to stress, which in turn may cause sleep disturbances and cardiovascular issues. In addition, noise can reduce overall well being and negatively affect rest and concentration. When noise exposure is too high, quality of life can therefore be significantly diminished.

Noise limits are intended to minimize these health risks by establishing clear requirements for companies, operators and residents. They form the basis for the approval of construction and operational projects and help to prevent conflicts.

• Noise Protection Ordinance

In Switzerland, the assessment periods differ for aircraft noise and industrial or commercial noise, as the two types of noise have different effects and must therefore be evaluated differently.

Aircraft Noise

The assessment of aircraft noise is divided into several periods:

• Day: 06:00 to 22:00
• Night period: divided into three individual hours
  – First night hour: 22:00 to 23:00
  – Second night hour: 23:00 to 24:00*
  – Third night hour: 05:00 to 06:00
  * also includes aircraft noise occurring between 00:00 and 05:00

This detailed subdivision of the night period reflects the increased sensitivity during rest times.

Industrial and Commercial Noise

The following periods apply:

• Day: 07:00 to 19:00
• Night: 19:00 to 07:00

When assessing industrial and commercial noise, additional penalties (corrections) are applied for particularly disturbing sound characteristics. These may include tonal noises (specific whistling tones) or rhythmic noises, which are perceived as especially intrusive.