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ARE - BS Acoustics
Acoustics
Question | Answer |
---|---|
Decibel (dB) | Unit of sound intensity devised to describe sound magnitude |
Noise Reduction Coefficient (NRC) | Scalar representation of the amount of sound energy absorbed upon striking a particular surface |
Sound Transmission Class (STC) | Single number average of how well a building partition reduces the force of airborn sound |
Velocity | Speed of sound. Dependent on the medium in which sound is traveling and the temperature of said medium |
Frequency | Number of cycles per second, measured in Hz |
Power | Quality of acoustical energy, measured in watts |
Smallest difference in 2 sounds that the human ear can detect | 1 dB |
Doubling the distance between the source and ear reduces the sound level by this factor | 6 dB |
Doubling the distance between the source and ear reduces the sound level by this factor on freeways | 3 dB |
Typical STC rating for walls, floors, and ceilings | 50 |