A white noise machine is a device that produces a sound that is random in character, somewhat like air escaping from a balloon. They generally do not produce actual white noise, which has a harsh sound, but more often pink noise, whose power rolls off at higher frequencies, or other colors of noise. They are often used to protect privacy by masking distant conversations, say in a psychiatrist's waiting room, and are also sold as sleep aids. Such machines often can produce other soothing sounds, such as rain, wind, and ocean waves. They are often used by suffers of tinnitus to mask their symptoms.

Simple machines consist of a very basic setup, involving an enclosed fan and (optionally) a speed switch. This fan drives air through small slots in the machine's casing, producing the desired sound. More complex machines may be electronic, and offer a variety of 'nature sounds' in addition to white noise.

Some claim employing white noise machines in offices improves productivity by reducing distractions, though this use is controversial.

Noise | Privacy | Sleep