What is Pink Noise?

Charity Delich

Pink noise is a type of signal that contains all of the sound frequencies that fall within the range of a human being’s hearing — from the lowest pitches that a person can hear to the highest tones. A variation of white noise, it is usually created when these audible tones are joined together at the exact same time and density. It is sometimes referred to as 1/f noise or flicker noise.

Offices may use pink noise to help employees concentrate.
Offices may use pink noise to help employees concentrate.

Distinct from white noise, pink noise emphasizes lower frequencies, and its amplitude drops off at a constant rate for each octave, typically three decibels. With pink signals, lower sound frequencies are usually louder and have more power than higher frequencies. In scientific terms, it has a frequency such that its power spectral density is inversely proportional to its frequency. On the sound frequency spectrum, pink falls between white and red noise, also known as Brownian noise.

To people, pink noise sounds like ocean waves.
To people, pink noise sounds like ocean waves.

To a person’s ears, pink noise is often flat, sounding like the buzz on an empty television station or the sound of ocean waves. This resonance is due to the noise being based on octaves rather than on individual frequencies. Typically, it is created by filtering white noise. The octaves occurring within the noise hold equal amounts of frequency, which result in a sound wave that has equal energy at each octave.

People with sleep disorders may benefit from pink noise machines to help them sleep through the night.
People with sleep disorders may benefit from pink noise machines to help them sleep through the night.

Pink noise can be mixed with other noises in order to create sound masking programs. For example, pink sound systems may be designed to simulate running water, a fan, or the sound of the sea. Given its soothing qualities, some people play it as background noise to help them relax. People who have sleep disorders may even purchase specialized pink sound sleep machines to help them doze off or stay sleeping throughout the night.

In particular, this noise is useful in masking low frequency sounds because it contains lower frequency levels than other types of noises. For example, pink sounds can mask noisy cars or loud industrial plants, so some employers play it in their offices to help their employees concentrate.

Pink noises have other uses as well, such as measuring the frequency response of acoustic equipment. Some synthesizers contain dedicated pink signal circuits that are used to simulate sounds like water, gunshots, wind, or explosions. Pink signals are also sometimes used when producing special effects for films, television shows, and video games. Frequently, they are used to test and equalize loudspeakers in rooms and auditoriums.

Pink noise may be used to test and equalize loudspeakers at a convert venue.
Pink noise may be used to test and equalize loudspeakers at a convert venue.

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Discussion Comments


To post 5 and post 3. You may be suffering from Hyperacusis. See Hyperacusis online. I am not permitted to include a link.


I can't find a pink noise or brown (Brownian) noise machine. Need one to help me sleep through neighbor's booming subwoofer bass noise all day and night. I already have two white noise machines that don't mask the neighbor's 84+dBC, <250Hz frequency. I don't want "nature sounds," just low frequency static. Can anyone suggest a brand or website where I can find such a machine?


I can handle the sound of traffic passing by, but their booming stereo's irritate me. I also get stressed and angry by people shouting in the street, and having to listen to my neighbours' conversations through the walls of my flat.


@anon319739: If certain noises that go unnoticed by other people bother you, some anti-anxiety medications may help. Antidepressants might but for the most part those aren't treating the right condition if you're purely sensitive to certain sounds. I'm not a doctor though. I'd recommend explaining it to your doctor and see what they say. It's not a well-known condition, so don't be surprised if you end up having to do lots of explaining.


I hate the noises people make while they eat, so I am pretty sure I have noise anxiety. How do I treat this?


@anon247682: If certain sounds that go unnoticed by others bother you, you might be suffering from misophonia. It's a little known neurological condition. Look into it and see if the symptoms sound like what you're experiencing when 'trigger sounds' occur.


I am dealing with noise anxiety but don't know which kind. I get angry when people talk at once, make chewing noises, pencil noises, and all the possible noises which are unnoticed makes me irritated. Even a very quiet silence makes me start wondering. I have headaches and I can't bear it. Please help.


I often have trouble sleeping through the night, although I think it has more to do with trying to live with one person who stays up late and one person who gets up early than anything else. However, I might consider a pink noise machine if this keeps being a problem after I move at the end of the year.


I had heard before that pink noise can often be more soothing than white noise, and so pink noise generators more helpful for people when trying to sleep. However, I didn't realize it was a technical term as well.

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