White Noise

Background

The energy distribution of white noise is flat, e.g. the frequency bands [10Hz-20Hz] and [10.000Hz-10.010Hz] contain the same energy. In other words, white noise contains all frequencies in equal proportion. For the human auditory system - which processes audio in a logarithmic frequency scale - white noise sounds much brighter than pink noise.

Applications

White noise is used as a reference tone to check frequency responses or the adverse effects of room modes.

Usage

Play back the file through your system and check its response with a linear FFT analyzer. The response should be flat when averaged over time. Beware: most spectrum analyzers integrate energy over log-scaled frequencies and using pink noise is often more appropriate.

White Noise @ -3dBFS

Links

• White Noise @ Wikipedia