The frequency response of pink noise drops with frequency - lower frequencies have more energy than higher frequencies. Pink noise sounds softer, less harsh than white noise, a little bit like a low hiss. It is usually artificially generated by low-pass filtering white noise. Pink noise is often used in audio measurements as a test signal. Almost all professional frequency analyzators have logarithmic frequency bands, the scale is more exact is lower frequencies than in higher frequencies.
Pink noise comes handy here.
An audio frequency analyzator will show flat picture when the input is pink noise. Noise in Music Richard. Some of the very modern composers such as Stockhausen, Jolet and Carter make an exception. The melody fluctuations in their music approach white noise at low frequencies. There was a resonant response of the brain wave to the complexity of these signals.