The white noise is an amalgam of sounds within the auditory spectrum of the human being, all sounding at the same time. The brain can only interpret so many sounds once, and when it encounters thousands of sounds that generate the white noise, the brain interprets it as a distant blast or rumble. Imagine opening the window of a skyscraper in downtown Manhattan. The sound of traffic, people, and other noises, all mixed in such a way that no sound prevails over the others, resulting in a distant and indistinct “woosh.” This is the nature of white noise.
The white noise is derived from the concept that white light contains all colors in the spectrum. Thus, like white light, white noise has all sounds.
Understanding white noise machines
A white noise machine, or sound conditioner, imitates or produces white noise through mechanical or electronic means.
A mechanical sound conditioner uses a small fan to generate white noise and has several switches that adjust the air intakes, changing the tone of the sound. The advantage of mechanical sound conditioners is that they produce a continuous and familiar sound. One disadvantage is that the volume is not adjustable.
Electronic sound conditioners produce either a continuous synthetic noise or a pre-recorded noise in a constant cycle. Electronic sound conditioners generally play different types of sounds like sea waves, rain falling, or wind. The drawback of repeating sound is that there is always a small fault between the end and the beginning of the cycle. Some people may hear this fault, and thereby deny the effect of white noise.
How white noise effects
The white noise does not drown the other sounds; rather, it incorporates them. As indicated above, when the brain is confronted with thousands of sounds at once, it is unable to differentiate one sound from another. When a white noise machine is active, any additional sound is lost among thousands of sounds that are playing in the same space. As a result, the sounds are still there but muted.
Another effect of white noise is relaxation. Because all noise is reduced to a soft, loud, and consistent murmur, it calms the central nervous system.
White noise machines are not as effective against sharp or intermittent noises, and it is possible to cancel the effect of white noise by focusing on a sound or group of sounds. This is the reason why it is possible to hear a person speaking in a murmuring crowd or why the tone of an alarm can be heard beyond a white noise machine.