(classical music)
- Crossover into Brain
Stuff now, children.
All are welcome.
But before we go into the light together,
there seems to be some confusion among you
about what white noise is.
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."
White noise is something 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.
(light crackling)
Each of these frequencies is
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 these notes.
That's why they're so good
at creating background noise
that masks other sounds.
When there are sudden changes in noise,
we're often distracted
by the jarring clash,
especially if we're sleeping.
White noise's masking effect
blocks out those changes,
making it easier to
sleep through the night.
That's one reason some people
leave a fan, air purifier,
or a television on in
the middle of the night.
This sound masking is
also used to block noise
in places like offices,
hotels, and libraries,
often broadcast over a P.A. system.
If you're trying to concentrate
in a disturbing environment
like our office
and there aren't filters
like these in place,
you can always listen to
white noise on your headphones
to mediate the conflicting
sounds around you.
I mean, how do you think we
write these Brain Stuff episodes
when we all live together
in this tiny studio prison
and are never allowed to leave?
(whispers) Send help.
There is peace and serenity
in the white noise.
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.
But white noise isn't the only
color on the sound spectrum.
Depending on the way
signals are distributed
over different frequencies,
they can be red, blue, violet, or gray.
Pink noise, for example, is
very similar to white noise,
but its higher frequencies
have less intensity,
making it louder and more
powerful on the low end.
(light crackling)
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 bodies.
Do you use some kind of white noise
to block out background sounds?
What's your favorite color of noise?
Let us all know in the comments below
and while you're down there,
could you very quietly click
on that subscribe button?
Thanks a lot.
