ABSTRACT
Frequency weighting involves emphasizing/suppressing certain parts of the spectrum of an audio signal. In practice, the weighting filter is inserted into the electrical part of the measurement sequence, either in form of a physical filter or a computational calculation. A-weighting applies, in particular, to the measurement of acoustic noise at the workplace and in the environment. The B, C, and D weightings belong to the same “family” as A-weighting. Originally the idea was that different weightings should be used depending on the level of sound. The C-weighting often applies to the measurement of the maximum sound pressure levels of public address systems and cinema loudspeaker arrays, and also in some cases for the measurement of monitoring levels. Other frequency weightings exist, of which some are only of limited use, and some are losing popularity. J.17 emphasis got its name after the International Telecommunication Union standard described this curve.
