White noise, by the technical definition, is a consistent noise that comes out evenly across all hearable frequencies. White noise is just an equal amount at every frequency, from low to high, that a human being can hear. When a noise wakes you up in the night, it's not the noise itself that wakes you up, per se, but the sudden change or inconsistencies in noise that jar you. White noise creates a masking effect, blocking out those sudden changes that frustrate light sleepers, or people trying to fall asleep. "The simple version is that hearing still works while you're asleep," says Seth S. Horowitz, a neuroscientist and author of The Universal Sense: How Hearing Shapes the Mind.

*Lecher, Colin. "FYI: Why Does White Noise Help People Sleep?" Popular Science. Popular Science, 14 Feb. 2014. Web. 07 Apr. 2015.

LectroFan’s non-repeating (temporal variable) white noise and fan sounds are dynamically generated using an algorithm that creates a truly random sound. Other white noise machines use looping sound clips that wakes up your brain, while others use actual fans that can’t get loud enough to block out anything. LectroFan has adjustable volume control to mask all levels of noise and a timer for those mid-day naps.