‘White noise’ is a catch-all term for any type of random sound signal that masks louder background noises. In most cases, white noise takes the form of soothing natural or ambient sounds. White noise is considered a sleep aid because it drowns out other, more disruptive sounds that prevent people from falling and/or remaining asleep.
Many adults rely on white noise machines to fall asleep each night, and some models are designed specifically for young children. White noise machines are also a popular travel accessory that can be used on airplanes and other forms of public transport, and in hotels, guest rooms, and other places with outside noise potential. A wide range of white noise machines are currently available at different price-points; some newer models are equipped with additional, high-tech features.
This guide will explore how white noise machines work, provide shopping tips, and list a few of our top-rated models. First, let’s look at the science behind white noise.
How Does White Noise Work?
Every sound we hear has two distinct components: the frequency, or the number of vibrations the sound wave produces per second (measured in hertz, or Hz); and amplitude, which measures the size of the sound waves. Whenever a frequency is halved or doubles, this is known as an octave.
Noise is categorized by colors that represent different audio signals and textures. Some of these colors — such as pink, blue, and brown — refer to sound waves that increase or decrease in volume, depending on changes in the frequency. White noise, on the other hand, maintains the same volume regardless of frequency and randomly combines every possible frequency that is audible to the human ear. The result is the telltale ‘shh’ sound that is commonly associated with white noise.
Technically speaking, most instances of ‘white noise’ are actually ‘pink noise.’ White noise matches any frequency, meaning that it may sound extremely high or extremely low. As a result, white noise on its own is too harsh for most human ears. Pink noise, on the other hand, gradually decreases in volume (measured in decibels) per octave, creating a more balanced listening experience. Most describe pink noise as white noise with a lower, bass-like quality.
Additionally, ‘brown noise’ (also known as ‘red noise’) is a deeper variant of pink noise, decreasing in volume at a faster per-octave rate. ‘Blue noise’ and ‘violet noise’ are the exact opposite, increasing in volume as the frequency rises. ‘Grey noise’ is a bit more complex; it increases or decreases in volume depending on the frequency, and sounds equally loud at all frequencies as a result. Black noise, as the name implies, refers to complete silence.
The table below includes a detailed breakdown of the five most common noise colors.
How Frequency Affects Volume
Volume remains constant regardless of frequency
Volume decreases by 3 db per octave
Volume decreases by 6 dB per octave
Waves or low wind
Volume increases by 3 dB per octave
Hissing or high wind
Volume increases by 6 dB per octave
Volume decreases between 100 and 1,000 Hz, and increases between 5,000 and 10,000 Hz
Static with volume that remains constant
No volume whatsoever
Despite these technical specifications, the term ‘white noise’ is generally used to describe any soothing natural or ambient sound that is used to drown out distracting background noises, such as vehicles on the road or noises from elsewhere in the house. This allows people to focus less on exterior sounds and fall asleep more quickly.
Three common examples of white noise include:
Natural sounds, such as waves, rain, wind, and gentle animal noises (such as crickets or birds)
Ambient sounds, which mimic common noises like burning fires, crowds of people, or light traffic
Machinery, such as air fans and other devices that emit light sounds (like dishwashers or washing machines)
White Noise Machines: Common Characteristics and Functions
In addition to aiding adults, most white noise machines are also designed for babies, infants, and young children. Some models feature softer, more soothing sounds as well as lullaby melodies, that specifically cater to young ears. White noise machines are also a popular travel accessory, and some models are designed for mobility with more compact sizes and dual-voltage capabilities.
Although specs vary by brand and model, most standard white noise machines sold today are designed for the following:
Volume: White noise machines always have adjustable volume settings.
Size: White noise machines are usually compact, and do not measure more than 10W” x 10L” x 10H”.
Sound options: In addition to traditional white noise, some white noise machines are equipped with multiple sound options, including natural and ambient sounds.
Looping: For less distraction, white noise machines often mask their sound loops to create a continuous listening experience.
Timer: Users may be able to program their white noise machine to stop producing sounds after a certain amount of time has passed.
Headphone accessibility: Some white noise machines feature built-in headphone jacks for more private listening.
Alarm: Select white noise machines come equipped with a programmable alarm.
Power: Some white noise machines operate using batteries, while others require an electrical outlet. Modern designs may also be powered using USB cords, as well.
With few exceptions, white noise machines cost $100 or less when purchased from the original manufacturer or authorized retailers. Some white noise machines come with warranties that cover up to five years, while others do not come with any warranty coverage.
Considerations for White Noise Machine Shoppers
When shopping for a new white noise machine and comparing different brands and models, here are a few important factors to keep in mind:
Will adults or children primarily use the machine?
Will the machine be exclusively used in the owner’s home, or will it also be used as a travel accessory?
How large is the machine, and will it fit where the owner plans to install it?
Is the machine too large for the owner’s current travel bags or luggage?
How many volume settings does the machine have?
Does the machine only feature white noise, or are there other sounds (such as natural, machine, and/or ambient sounds)? If the latter, how many total sounds are featured?
Does the machine mask sound loops, or are there brief periods of static or silence between the end of one loop and the beginning of the next?
Does the machine feature a programmable timer that controls when the noise stops?
Does the machine come with a built-in alarm clock?
Does the machine have a headphone jack?
Does the machine run on batteries, AC, or USB?
How much does the machine cost?
Is warranty coverage included with the machine?
Best White Noise Machines: Brands and Models for All Ages
Now, let’s look at the white noise machines that have earned the highest ratings from owners and customers. The first table features our top-rated low-cost white noise machines; each model is priced at $40 or less.
Best White Noise Machines: Brands and Models for Kids
Although most white noise machines for adults are also suitable for children, some models are specifically designed for younger listeners. The next table features our four top picks for the best kid-friendly white noise machine options.
Sound of Sleep
MyBaby Deep Sleep SoundSpa
6.3D” x 7.9W” x 8.7H” (This design is a plush stuffed sheep with a built-in white noise machine)
3.9D” x 3.9W” x 3.1H”
3.5D” x 1.8W” x 3.8H”
7D” x 9W” x 3H”
Mother’s heartbeat Spring showers Ocean surf Whale songs 4 lullabies
3 white noise settings Ocean Heartbeat Twinkle Twinkle (lullaby)
Bright and deep white noise Gentle surf
75 total sounds 12 white, pink, and brown noises 24 lullabies 8 fan settings 20 natural sounds
For sleepers who prefer not to use or invest in a white noise machine, effective methods of blocking outside noise include the following:
Fans: The whirring blades of conventional fans produce ambient white noise that can effectively drown out other sounds. They also improve air circulation in the bedroom, and can create a cooler sleeping space during warmer times of the year.
Earplugs: Some people prefer to sleep with earplugs, which are normally made from softer materials like foam or silicone. Earplugs may mold to the contours of the user’s inner ear, or they may maintain a constant shape; in either case, they are usually designed to fit all ear canal sizes. Some earplugs are reusable, while others are designed for one-time use.
Most earplugs are sold in bulk, and typically cost less than $30 for a pack of 200 or less. However, it’s important to note that earplugs are associated with certain health risks, namely earwax buildup, which can lead to conditions like hearing loss, tinnitus, and earwax discharge.
White noise apps: Downloading a white noise app onto a smartphone, tablet, or other portable electronic device may be a cheaper alternative to purchasing a white noise machine. White noise apps may also allow users to play music from their personal library or streaming services while the white noise sounds play.
The table below lists five of the most popular white noise apps that are currently available on iTunes.
6+ ambient options that recreate coffee shop chatter
White noise 7 natural and ambient options
White, pink, and brown noise 12 natural and ambient options
4 fan sounds
White, pink, brown, blue, and violet noise 35 natural and ambient sounds