Pink Noise

Pink noise refers to an audio signal that contains a full range of frequencies at the same loudness, with equal energy in all octaves.

Pink noise sounds like soft static with prominent low end frequencies, whereas white noise sounds like intense static because it contains more upper frequencies. To make every frequency sound at the same loudness, more energy is needed to push the long, low frequencies out at the same rate as the quick, short, upper frequencies.

Pink noise is often used in audio engineering for azimuth and frequency alignment and to aid in calibrating audio monitor levels.

This definition/image is licensed under the GNU Free Documentation License found at http://www.gnu.org/copyleft/fdl.html . It uses material from the Wikipedia article at http://en.wikipedia.org/wiki/Pink_noise.

Pink noise.

Pink noise spectrum.