Audio Fundamentals
Pink noise is a type of random noise signal with equal energy per octave, meaning its power decreases as frequency increases. It sounds smoother and less harsh than white noise and is often used for acoustic measurement, equipment testing, and mixing reference.
In pink noise, the amplitude of each frequency component is inversely proportional to its frequency. This produces a power spectrum that drops by 3 dB per octave, resulting in a balanced distribution of energy across the audible spectrum. Because human hearing perceives sound roughly on a logarithmic scale, pink noise sounds more even and natural to the ear compared to white noise, which contains equal energy at all frequencies and therefore sounds brighter.
Pink noise plays a crucial role in professional audio work. It is used to tune loudspeaker systems and studio monitors by analysing how a room or system alters its frequency balance. Engineers measure the system’s response to pink noise using a spectrum analyser and adjust equalisation to achieve a flat response. It is also used in electronic circuit testing, acoustic research, and psychoacoustic studies.
In mixing and mastering, pink noise can serve as a reference for setting relative levels. By matching the overall balance of a mix to a pink noise reference, engineers can achieve more consistent tonal results across different playback systems.
Pink noise should not be confused with white noise or brown noise, which have different spectral characteristics. Its consistent energy distribution per octave makes it a valuable tool for both calibration and creative sound design.
