Comparing Noise Criteria

Comparing Noise Criteria - Noise Criterion (NC, NCB, RNC), Noise Rating (NR) and dB(A)

Noise Criterion - NC - were established in U.S. for rating indoor noise, noise from air-conditioning equipment etc.

In Europe it is common to use Noise Rating Curves - NR.

dB(A) - LA - is a weighted method compensating for the human hearing of sound pressure at different frequencies.

Choosing appropriate noise criteria is important when specifying acceptable levels of noise. Most organizations use a particular index based upon practical experience. Recommended maximum noise levels for different types of rooms and standards are indicated in the table below

Type of Room - OccupancyMaximum Level (dB)
Noise Criterion
- NC, NCB, RNC -
Noise Rating
- NR -
Very quiet Concert and opera halls, recording studios, theaters, etc. 10 - 20 20 25 - 30 20
Private bedrooms, live theaters, television and radio studios, conference and lecture rooms, cathedrals and large churches, libraries, etc. 20 - 25 25 25 - 30 25
Private living rooms, board rooms, conference and lecture rooms, hotel bedrooms 30 - 40 30 30 - 35 30
Quiet Public rooms in hotels, small offices classrooms, courtrooms 30 - 40 35 40 - 45 35
Moderate noisy Drawing offices, toilets, bathrooms, reception areas, lobbies, corridors, department stores, etc. 35 - 45 40 45 - 55 40
Noisy Kitchens in hospitals and hotels, laundry rooms, computer rooms, canteens, supermarkets, office landscape, etc. 40 - 50 45 45 - 55 45

Related Topics

  • Acoustics - Room acoustics and acoustic properties - decibel A, B and C - Noise Rating (NR) curves, sound transmission, sound pressure, sound intensity and sound attenuation

Related Documents

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