The law of noise pollution
These regulations have a goal to promote the health and prosperity of human beings by having a requirement to noise level and secure that the law is being followed. These basic values are to be considered as maximum values considering existing activity. The regulations concerned airborne noise and are valid in residents(which people live in all year long), kindergartens, educational-institutions and health-institution.
Value limit (inside buildings) 24hrs average 35-dB (A)
When this value is being exceeded, charts and enterprise-elucidations are to be carried trough after § 5-7.
National demand (inside buildings) 24hrs average 42-dB (A)
If this value is being exceeded, enterprises are to be carried through after § 8.
For more detailed information concerning the law of noise pollution follow this link: http://www.sft.no/40b.html
The link leads you to a page written in Norwegian, only.