RC - the Room Criteria

The Room Criteria (RC) is used to measure background noise in buildings for frequencies ranging 16 to 4000 Hz. RC requires a determination of the mid-frequency average level and the perceived balance between high and low frequency sound.

RC - the Room Criteria

The Room Criteria (RC) is used to measure 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.

Neutral (N) Criteria

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.

Type of Room - Space TypeRecommended RC Level RC CurveEquivalent Sound Level dB(A)
Apartments25 - 35 (N)35 - 45
Assembly Halls25 - 30 (N)35 - 40
Churches30 - 35 (N)40 - 45
Courtrooms30 - 40 (N)40 - 50
Factories40 - 65 (N)50 - 75
Hotels/Motels - Individual rooms or suites30 - 35 (N)35 - 45
Hotels/Motels - Meeting or banquet rooms25 - 35 (N)35 - 45
Hotels/Motels - Service and Support Areas40 - 45 (N)45 - 50
Hotels/Motels - Halls, corridors, lobbies35 - 40 (N)50 - 55
Offices - Conference rooms25 - 30 (N)35 - 40
Offices - Private30 - 35 (N)40 - 45
Offices - Open-plan areas35 - 40 (N)45 - 50
Offices - Business machines/computers40 - 45 (N)50 - 55
Hospitals and Clinics - Private rooms25 - 30 (N)35 - 40
Hospitals and Clinics - Operating rooms25 - 30 (N)35 - 40
Hospitals and Clinics - Wards30 - 35 (N)40 - 45
Hospitals and Clinics - Laboratories35 - 40 (N)45 - 50
Hospitals and Clinics - Corridors30 - 35 (N)40 - 45
Hospitals and Clinics - Public areas35 - 40 (N)45 - 50
Schools - Lecture and classrooms25 - 30 (N)35 - 40
Schools - Open-plan classrooms30 - 40 (N)45 - 50
Movie motion picture theaters30 - 35 (N)40 - 45
Libraries35 - 40 (N)40 - 50
Legitimate theaters20 - 25 (N)30 - 65
Private Residences25 - 35 (N)35 - 45
Restaurants40 - 45 (N)50 - 55
TV Broadcast studios15 - 25 (N)25 - 35
Recording Studios15 - 20 (N)25 - 30
Concert and recital halls15 - 20 (N)25 - 30
Sport Coliseums45 - 55 (N)55 - 65
RC - the Room Criteria | MEPKit Engineering Tools | MEPKit