Noise measurement
From Wikipedia, the free encyclopedia
Noise measurement is carried out in various fields.
In acoustics, it can be for the purpose of measuring environmental noise, or part of a test procedure using white noise, or some other specialist form of test signal.
In electronics it relates to the sensitivity of radio systems, the purity of signals, or the quality of audio systems.
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.
[edit] Standards
There are a number of competing standards for noise measurement, including:
- Standard:ITU-R 468 widely used in Broadcasting and professional Audio.
- Standard:IEC A-weighting is widely used in Environmental Noise measurement.
- Standard:CCIR recommendation 468-4 is now maintained as ITU-R 468
- Standard:CCITT 0.41 refers to 'Psophometric weighting' used on telephone circuits.
- Standard:CCITT P53 is now continued as CCITT0.41
- Standard:BS 6402:1983 specifies Personal sound exposure meters.
- Standard:BS 3539:1968 specifies Sound level meters for motor vehicle noise.
- Standard:BSEN 60651 supersedes BS 5969:1981 Sound level meters
