Where is the white noise coming from?

What is White Noise?

White noise refers to a random signal with a flat power spectral density. In other words, the signal contains equal power within a fixed bandwidth at any center frequency. It sounds like a hissing, rushing, or static noise. White noise gets its name because it contains all frequencies, just like white light contains all colors (From Wikipedia).

Some examples of white noise are the sound of air coming out of an air conditioner, the humming sound of a fan, the static sound heard between stations on an AM radio, and the background hiss on a phone call. These sounds contain a random mix of all audible frequencies distributed evenly across the spectrum (From Merriam-Webster).

White noise is called such because it contains all frequencies of sound mixed together, giving it a white appearance in terms of sound and frequency, just as white light contains all the colors of the visible spectrum (From Cambridge Dictionary).

Natural Sources

Wind, waves, rainfall and other ambient sounds are common natural sources of white noise. The sound of wind rustling through trees and blowing past buildings produces a soft, gentle hissing noise spanning a wide range of frequencies that masks other sounds. The Ocean’s continuous waves crashing onto the shore generate a soothing, rhythmic white noise similar to rainfall. The pitter-patter of raindrops on surfaces like roofs, windows, or leaves is a familiar ambient noise with a calming, steady quality. Other natural sounds like crackling fire, insects, or distant bird calls can provide relaxing background white noise as well.

Artificial Sources

White noise can also be artificially generated from common household appliances and electronics. Some of the most common artificial sources of white noise include:

Fans
The steady hum of ceiling fans, box fans, and other types of electric fans generate white noise by moving air. The consistent whooshing sound has a flat power spectrum, qualifying it as white noise.^[1] Using a fan is a popular way to produce background white noise at home.

Air conditioners

The motor and air movement from air conditioning units create a continual white noise. This underscores why many people find it easier to sleep in air conditioned rooms. The a/c unit’s drone covers other sporadic noises that might otherwise wake someone up.^[2]

Refrigerators

Refrigerator compressors turning on and off emit a whitish hum. Although not a pure white noise, the regular cycling creates a masking effect. Some even find the frequent starting and stopping of the compressor relaxing in its predictability.

Other household appliances

Devices like vacuums, washers, dryers, and dishwashers produce white noise too. The sounds aren’t constant, but the regular drone and whirring covers sudden noises during operation. White noise machines sometimes even simulate these household appliance sounds.^[3]

<sup>[1] https://en.wikipedia.org/wiki/White_noise
[2] https://psmag.com/news/the-art-and-science-of-white-noise

[3] https://www.healthline.com/health/pink-noise-sleep</sup>

Artificial Sources: Electronic Devices

Electronic devices like radios, TVs, computers, phones and other electronics are common sources of white noise in modern life. The faint humming or buzzing sounds emitted from these devices when turned on but not actively in use can blend into the background environment (Whitenoise.ie, 2022).

Older CRT computer monitors and tube TVs were known for producing high-pitched whining or buzzing noises, especially as the technology aged. Modern flatscreen displays generate less noise but can still emit a subtle hum or hiss from their electronics and power systems that is perceivable in quiet environments (Whitenoise.ie, 2022).

Audio components like radios, media players and speakers also contribute background hissing sounds even when no audio is actively playing. The electric current running through the system produces electromagnetic fluctuations that can be heard as white noise (NSDR, 2022).

Mobile phones and other portable electronics like laptops have small but powerful electronic components and antennas packed into a compact chassis. These can vibrate or resonate at high frequencies, producing a faint hissing or staticky sound. Using devices in areas with poor reception can make this worse (NSDR, 2022).

Basically any electronic or electric tech contains components that can generate white noise type sounds when energized. This noise may be imperceptible when such devices are in active use, but in a sufficiently quiet space the ambient hum or hiss of electronics can become audible.

White Noise Machines

White noise machines are devices that produce soothing background sounds to help block out disruptive noises that can interrupt sleep. They work by emitting a steady, unobtrusive sound at a constant volume and frequency distribution (source: The Best White Noise Machine – Wirecutter).

There are different types of white noise machines:

• Fan sound machines mimic the soothing hum of a fan.
• Natural sound machines produce calming nature noises like ocean waves, rainfall, or crickets.
• White noise machines generate a static hiss that dulls background noise.

The benefits of using a white noise machine include:

• Blocking out disruptive noises that can prevent sleep.
• Promoting relaxation by providing a consistent ambient sound.
• Masking noises like snoring or outside traffic.

Some drawbacks of white noise machines include:

• The sound may be distracting for some users.
• They require electricity to operate.
• Some models may produce sounds that are repetitive or irritating.

How We Perceive It

Our ears and brains perceive white noise in several key ways:

First, white noise triggers noise cancellation in the inner ear. The cochlea contains outer hair cells that contract in response to low-level noise, which counteracts and cancels out background sounds ^[1]. This allows other more relevant sounds to stand out.

Second, steady white noise helps fill in gaps of silence in the auditory environment. The auditory system is highly sensitive to change, and sudden drops in sound can be jarring. Continuous white noise creates a consistent sound blanket that minimizes these gaps ^[2].

Third, white noise can mask other distracting or unpredictable sounds. The relatively constant backdrop of white noise makes those other sounds fade into the background, acting as an auditory distraction blocker ^[1].

Uses of White Noise

White noise can have several helpful uses according to studies. One of the most popular uses is for improving sleep. The sound of white noise can help people fall asleep faster and get better quality sleep (https://www.soundproofcow.com/benefits-white-noise/). The consistency of the sound blocks out other noises that may disrupt sleep like traffic, neighbors, or a snoring partner. White noise provides a calming ambiance that relaxes the mind and body and makes it easier to drift off to sleep.

White noise is also useful for increasing focus while studying or working. The neutral background sound helps block out small distractions so you can concentrate better. One study found white noise improved performance on cognitive tasks requiring sustained attention, particularly for those prone to distraction (https://www.mylicon.com/advice-item/white-noise/). The sound covers up nearby conversations, doors opening and closing, or other irregular noises that can break concentration. This allows people to stay focused on the task at hand.

In addition to sleep and focus, white noise can provide relaxation and help manage stress. The consistent ambient sound has a soothing quality that can lower heart rate and blood pressure. Playing white noise in relaxing environments like spas helps create a calm atmosphere. The sound blankets the environment and masks other noises that could be jarring or disruptive.

White noise machines are also used to mask unwanted distractions and sounds. The white noise covers up noises that would otherwise be annoying like loud neighbors, construction work, or traffic. It can make these disturbances less noticeable so they don’t interrupt daily activities or conversations. Parents often use white noise to cover up household noises so they don’t wake sleeping babies. The sound creates a more neutral environment by obscuring distracting sounds.

Downsides of White Noise

While white noise can provide benefits in certain situations, there are some potential downsides to be aware of:

Potential Hearing Damage

Exposure to loud white noise, especially for extended periods, may damage hearing over time. One study found that exposure to white noise above 50 A-weighted decibels (dBA) could negatively impact infant hearing and auditory development (Source). The safe noise limit for infants is below 45 dBA.

Adults exposed to white noise above 85 dBA for prolonged periods are also at risk for noise-induced hearing loss. So it’s important to keep white noise levels moderate and avoid excessive exposure.

Sleep Disruption

While white noise can help initially fall asleep, studies show it may disrupt sleep quality and can lead to more night wakings (Source). The noise may prevent people from reaching deeper stages of sleep.

Using white noise on occasion is likely fine, but relying on it regularly could interfere with quality sleep.

Masking Important Sounds

A constant white noise in the background can make it harder to hear other important noises like voices, alarms, or signals. This could be problematic if trying to listen for a baby crying or failing to hear emergency warnings.

It’s best to keep white noise levels low and focused where needed instead of broadly dispersed.

Managing White Noise

There are several techniques that can help manage white noise, especially for those who find it disruptive or bothersome:

Soundproofing techniques like installing insulation, weatherstripping doors and windows, and using rugs and curtains can help reduce external white noise in living spaces. White noise machines and fans can also mask unpleasant white noise by producingsteady, unobtrusive background sounds.

Noise-cancelling headphones utilize destructive interference to cancel out ambient noise. This technology is also used in some vehicles and even in noise-cancelling window installations. These can provide peaceful personal sound environments amid external white noise.

Creating relaxing spaces with soft furnishings, plants, calming colors and lighting, and minimal clutter can promote peace and relaxation, making white noise less intrusive. Maintaining mental wellness through meditation, counseling, stress reduction, and positive thinking can also help make white noise less bothersome by reducing reactivity to external stimuli.

Overall, while white noise can be distracting for some, there are many ways to manage it through soundproofing, noise cancellation, peaceful spaces, and mental wellbeing practices.

Conclusion

In summary, white noise is defined as a random sound with an equal intensity at different frequencies. It can come from natural sources like wind, rain, and rivers, or from artificial sources like appliances, machinery, and electronic devices. While white noise can help mask other distracting sounds and aid sleep, concentration or relaxation, it can also cause issues like hearing problems or increased stress if not managed properly.

Knowing the potential sources of white noise is key to controlling your environment. Natural white noise like fans or soothing sounds can be used intentionally to provide beneficial background noise. But other sources like AC units, refrigerators, or traffic noise may need mitigating for better health and productivity.

Overall, the careful and intentional use of white noise can be advantageous. But being aware of excessive exposure, managing levels, and reducing unwanted sources helps strike the right balance to gain its benefits without the downsides.