BrainStuff Classics: What Is White Noise?

White noise generators are useful for masking all kinds of annoying sounds -- but what is white noise, and how does it work? Learn about white noise (and other 'colors') in this episode of BrainStuff.

Learn more about your ad-choices at https://www.iheartpodcastnetwork.com

See omnystudio.com/listener for privacy information.

Episode Transcript

Speaker 1 (00:01):
Welcome to brain Stuff production of I Heart Radio. Hey,
brain Stuff, I'm Lauren Vogelbaum, and this is another classic
episode from our previous host, Christian Sagar. White noise generators
are a boon to some of us who work in
open office environments and need to concentrate, and to some
of us who are just trying to get a good
night's sleep. In today's episode, we explain why crossover into

(00:30):
brain Stuff. Now, children, all are welcome. I'm Christian Sager.
But before we go into the light together, there seems
to be some confusion among you about what white noises
no It isn't when you have that snowy static on
your TV and ghosts fly out of the screen and
your daughter says they're here. No. White noise is something

(00:52):
we've all heard, some of us without even knowing it.
So let's define what it is exactly, how it's used
to mask other sounds, and what other colors exist on
the spectrum of sound. The simplest definition is that white
noise is the noise produced by combining all the different
frequencies of sound together at once. Each of these frequencies

(01:13):
are projected at an equal amount from low to high.
Because white noise has an equal energy distribution. Sound technicians
refer to its frequency spectrum as being completely flat. Some machines,
like fans, for instance, can create an approximation of white
noise by hitting all of these notes. That's why they're

(01:33):
so good at creating background noises that masks other sounds.
When there are sudden changes in noise, were often distracted
by the jarring clash, especially if we're sleeping. White noises
masking effect blocks out those changes, making it easier to
sleep through the night. That's one reason some people leave
a fan and air purifier, or even a television on

(01:55):
in the middle of the night. This sound masking is
also used to block noise is in places like offices, hotels,
and libraries often broadcast over a p A system. If
you're trying to concentrate in a disturbing environment and there
aren't filters like these in place, you can even listen
to white noise on your headphones to mediate the conflicting noise.

(02:16):
How do you think we write these brain stuff episodes
when we all live together in this tiny little studio
prison and are never allowed to leave. There is peace
and serenity in white noise. It can also be used
as a kind of therapy for people with ringing ear,
also known as tenitis. I've got that because of its
equal high and low frequencies. For more info about how

(02:37):
ringing ear works, check out our previous episode on the topic.
And one other thing to note is that, because of
an effect called stochastic resonance, some people actually find that
white noise makes their tonitis worse. Now we call it
white noise because it's analogous to how white light works,
being made up of all the different frequencies of light.

(02:59):
But white noise isn't the only color on the sound spectrum.
Depending on the way signals are distributed over different frequencies
that can be red, blue, violet, or gray. Pink noise,
for example, is very similar to white noise, but it's
higher frequencies have less intensity, making it louder and more

(03:20):
powerful on the low end. This makes it useful for
testing speakers and amplifiers. Like white noise, it's also used
to mask background sounds, and pink noise even occurs naturally
in heartbeat rhythms, meteorological data, and the radiation output of
astronomical pods. Today's episode was written by Christian and produced

(03:45):
by Tyler Playing. Brain Stuff is a production of I
Heart Radios How stuff Works. For more on this and
lots of other topics, visit our home planet, how stuff
Works dot com. And for more podcasts my heart radio,
visit the heart Radio app, Apple Podcasts, or wherever you
listen to your favorite shows.