Simply Noise
If you have problem trying to catch up on some Z... Or for all that matter tired of counting away them sheeps, here is a cool alternative of White noise. So what da heck is it ? 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.