In acoustics, noise measurement can be for the purpose of measuring environmental noise, or part of a test procedure using white noise, or some other specialised form of test signal. In audio systems and broadcasting specific methods are used to obtain subjectively valid results in order that different devices and signal paths may be compared regardless of the differing spectral distribution and temporal properties of the noise that they generate. In particular, the ITU-R 468 noise weighting was devised specifically for this purpose, and is widely used for professional audio and broadcast measurements.
There are a number of standards for noise measurement, each with a different goal or focus, including: