RC - the Room Criteria
The Room Criteria (RC) is used to measure background noise in buildings for frequencies ranging 16 to 4000 Hz.
Room Criteria (RC) measures the background noise in buildings over frequencies ranging 16 Hz to 4000 Hz.
RC requires a determination of the mid-frequency average level and the perceived balance between high and low frequency sound.
| Type of Room - Space Type | Recommended RC Level RC Curve | Equivalent Sound Level dB(A) |
|---|---|---|
| Apartments | 25 - 35 (N)1) | 35 - 45 |
| Assembly Halls | 25 - 30 (N) | 35 - 40 |
| Churches | 30 - 35 (N) | 40 - 45 |
| Courtrooms | 30 - 40 (N) | 40 - 50 |
| Factories | 40 - 65 (N) | 50 - 75 |
| Hotels/Motels | ||
| - Individual rooms or suites | 30 - 35 (N) | 35 - 45 |
| - Meeting or banquet rooms | 25 - 35 (N) | 35 - 45 |
| - Service and Support Areas | 40 - 45 (N) | 45 - 50 |
| - Halls, corridors, lobbies | 35 - 40 (N) | 50 - 55 |
| Offices | ||
| - Conference rooms | 25 - 30 (N) | 35 - 40 |
| - Private | 30 - 35 (N) | 40 - 45 |
| - Open-plan areas | 35 - 40 (N) | 45 - 50 |
| - Business machines/computers | 40 - 45 (N) | 50 - 55 |
| Hospitals and Clinics | ||
| - Private rooms | 25 - 30 (N) | 35 - 40 |
| - Operating rooms | 25 - 30 (N) | 35 - 40 |
| - Wards | 30 - 35 (N) | 40 - 45 |
| - Laboratories | 35 - 40 (N) | 45 - 50 |
| - Corridors | 30 - 35 (N) | 40 - 45 |
| - Public areas | 35 - 40 (N) | 45 - 50 |
| Schools | ||
| - Lecture and classrooms | 25 - 30 (N) | 35 - 40 |
| - Open-plan classrooms | 30 - 40 (N) | 45 - 50 |
| Movie motion picture theaters | 30 - 35 (N) | 40 - 45 |
| Libraries | 35 - 40 (N) | 40 - 50 |
| Legitimate theaters | 20 - 25 (N) | 30 - 65 |
| Private Residences | 25 - 35 (N) | 35 - 45 |
| Restaurants | 40 - 45 (N) | 50 - 55 |
| TV Broadcast studies | 15 - 25 (N) | 25 - 35 |
| Recording Studios | 15 - 20 (N) | 25 - 30 |
| Concert and recital halls | 15 - 20 (N) | 25 - 30 |
| Sport Coliseums | 45 - 55 (N) | 55 - 65 |
| Recording studios | 15 - 20 (N) | 25 - 30 |
1) Neutral (N). The levels in the octave bands centered at 500 Hz and below must not exceed the octave-band levels of the reference spectrum by more than 5 dB at any point in the range; the levels in the octave bands centered at 1000 Hz and above must not exceed the octave-band level of the reference spectrum by more than 3 dB at any point in the range.
