Uncorrelated sound sources increase in level less than correlated ones do

Evidence

Adding uncorrelated sources is different from adding correlated sources in several respects. First, the resulting total is related to the power of the signals combined and so is not dependent on their relative phases. This means that the result of combining uncorrelated sources is always an increase in level. The second difference is that the level increase is lower because powers rather than pressures are being added. Recall that the maximum increase for two equal correlated sources was a factor-of-two increase in pressure amplitude. However, for uncorrelated sources, the powers of the sources are added and, as the power is proportional to the square of the pressure, this means that the maximum amplitude increase for two uncorrelated sources is only 2 . — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 246

Categorization

• DEFINE: Clarifies the distinction between correlated and uncorrelated sound addition.
• corroborated: 2 independent passages support this claim — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 246