Stricly apeaking

White noise is a random signal (or process) with a flat power spectral density. In other words, the signal's power spectral density has equal power in any band, at any centre frequency, having a given bandwidth. White noise is considered analogous to white light which contains all frequencies.

An infinite-bandwidth white noise signal is purely a theoretical construct. By having power at all frequencies, the total power of such a signal is infinite. In practice, a signal can be "white" with a flat spectrum over a defined frequency band.

In practice most sources are 'coloured', not 'white'.... :-)


Practical uses of White Noise MP3s for Tinnitus Treatment, Masking and Tinnitus Cure