A measure for rating the overall sound absorption performance of a material when used in an enclosed architectural space such as an office, where sound is being reflected at many angles of incidence. Specifically, it is the 4 frequency averaged absorption coefficients @ 250, 500, 1000 and 2000 Hz, rounded to the nearest 0.05. A material with NRC 0.50 is a poor absorber, and NRC .80 is a very good absorber.
A measurement of a material's ability to absorb noise.
The rating that identifies the ability of an object to absorb rather than reflect sound.
A single number rating, the arithmetic average of the individual sound absorption coefficients of a material at 250, 500, 1000 and 2000 Hz to the nearest .05.
A single-number rating system used to compare the sound-absorbing characteristics of building materials.
The NRC of an acoustical material is the mathematical average, to the nearest multiple of 0.05, of its absorption coefficients at center frequencies of 250,500,1000, 2000 Hertz Octave A pitch interval of 2 to 1. A tone whose frequency is twice that of the given tone.
A simplified rating of the sound absorbing properties of materials, in which the sound absorption coefficients at 250, 500, 1000 and 2000 Hz are averaged. Abbreviated: NRC. Obviously this is of no value in evaluating what happens at low, or very high frequencies. It is a speech-oriented measure. See: Sound Absorption Coefficient.
The NRC of an acoustical material is the arithmetic average to the nearest multiple of 0.05 of its absorption coefficients at 4 one-third octave bands with center frequencies of 250, 500, 1000, 2000 Hertz. The NRC rating can be viewed as a percentage (example: .80 = 80%) of what soundwaves that come in contact with the acoustical material are absorbed by the material and NOT reflected back within the room.
The measure of acoustical absorption calculated at specific mid-range frequencies. The Noise Reduction Coefficient is commonly used to rate the performance of acoustical ceilings.
The average of the absorption coefficients (รก) for the frequency bands 250 Hz, 500 Hz,1000 Hz, and 2000 Hz. Commonly used to describe the average absorption of acoustical materials such as ceiling tiles and wall panels.
The Noise Reduction Coefficient (commonly abbreviated NRC) is a scalar representation of the amount of sound energy absorbed upon striking a particular surface. An NRC of 0 indicates perfect reflection; an NRC of 1 indicates perfect absorption.