A white noise generator is a device that emits random background noise for the purpose of masking other sounds in the immediate environment. Many of the devices or machines sold as white noise generators actually play recordings of sounds found in nature, such as waterfalls, rain, and wind, rather than genuine white noise, which is a specific frequency that is harsh to the human ear and more closely resembles the hissing spray of an aerosol can.
A white noise generator may be used to assist with sleep, to relieve symptoms of tinnitus and migraines, to enhance privacy in public areas such as doctor’s offices, and by many emergency vehicles in conjunction with their sirens. The most common use for white noise is in the area of audio synthesis and electronic music production. A white noise generator used for professional audio equipment purposes is of a different variety than those sold for commercial use.
Several white noise generators which are sold as sleeping or relaxation aids continuously play or “loop” a short recorded audio segment intended to drown out background noise. This can sometimes cause a disturbance to the listener, whose ear may begin to pick up the variances between the beginning and the end of the sound segment. One of the oldest and most popular white noise generators on the market which is sold as a sleeping aid is the SleepMate 980®. This cylindrical desktop device employs a motor to produce the sound of rushing air, resembling the sound of a fan. The White Noise Generator TSC-330® by Marpac is another device sold as a sleeping and relaxation aid, and emits an electronic sound through a speaker which can be adjusted in volume or tone. The Sleep Eze In Ear White Noise Generator® is a different type of model that is placed inside the ear canals, similar to ear plugs, and emits white noise from tiny speakers.
Certain websites offer various spectrums of noise, including white noise, pink noise, and brown noise, available for downloading on the Internet. Other alternatives to purchasing a desktop white noise generator include listening to white noise CDs or audio files, listening to static between stations on a radio, or running a fan.