Twice the power corresponds to a 3 decibel increase, so white noise is said to increase 3 dB per octave in power. For processes of testing and equalizing rooms and auditoriums, it is convenient to have broad-band noise signals. Typically, white noise or pink noise is used. Since the number of Hz in each successive octave increases by two, this means the power of pink noise per Hz of bandwidth decreases by a factor of two or 3 dB per octave. Since pink noise has relatively more bass than white noise, it sounds more like the roar of a waterfall than like the higher hissing sound of white noise.
Pink noise is often the choice for equalizing auditoriums.
Real-time analyzers can be set up so that they display a straight horizontal line when they receive pink noise.