Capitalization - Sound Effects

In a screenplay, sometimes writers will draw the readers attention to sound effects by placing them in ALL CAPS. Other times sounds are left lowercase. Below is an example of a scene with sound effects:

The example above is an EXTREME example, as many of the sounds that are in CAPS are not very important and therefore wouldn't normally be CAPPED.

If this were a REAL script page, I MIGHT place the initial scream in ALL CAPS, but nothing else seems important enough to warrant such treatment.

However, I'll use this example as a teaching tool.

Notice that some sounds are offscreen and in ALL CAPS. Others are on screen and in ALL CAPS while still others are on screen and NOT in ALL CAPS.

Why is "knock" NOT capped when the door squeaking IS capped? Why are Harriet's screams capped sometimes but not other times? Why is the baby cries capped EVERYTIME?

For the answers to these questions and more, read on.

The Extremes:

Screenplay formatting experts simply cannot agree on how to approach the Capitalization of sound effects in Direction paragraphs.

At one extreme, experts say Capitalizing sound effects is a dead art and shouldn't be done today at all.

At the other extreme, experts believe a sound effect should not only be in ALL CAPS nearly every time, but that the object creating the sound effect should also be Capitalized.

The Trend:

The trend today is that writers are slowly fading out the Capitalizing of sound effects, and producers and agents seem to be okay with this shift. In shooting scripts, the practice is still strong, but in spec scripts, more and more writers are being advised to limit their Capitalization of sound effects.

My Advice:

Only Capitalize the important sound effects. So, in a gun fight, you might not Capitalize every time a gun fires...but you might Capitalize the first shot that started the gun fight.

With that in mind, as you read on down the page consider the formatting guidelines presented to be for those important sounds.

Four Rules of Sound Effects:

Rule #1 - Put offscreen sounds in ALL CAPS, even if made by a person.

Rule #2 - Put on screen sounds in ALL CAPS if they originate from a mechanical device.

Rule #3 - DO NOT put on screen sounds in ALL CAPS if they originate from a person.

Rule #4 - In every case, Capitalize ONLY the sound, not the device or person making the sound.

When to Capitalize:

Taking the rules above into consideration, that would mean the following sounds get the ALL CAPS treatment whether on screen or offscreen:

  • Weather sounds: thunderstorms, wind howling and whistling through trees, rain pouring, hail beating, etc.
  • Vehicle and Traffic sounds: cars honking, tires squealing, gears grinding, buses stopping, garbage trucks reversing (beep, beep, beep), train whistles, planes flying overhead, cars crashing, engines revving up or trying to turn over, etc.
  • Weaponry being used: Guns firing or cocking, bombs exploding, bullets ricocheting, bullet casings pinging on the ground, etc.
  • Electronics: Robots tinging and whistling, TVs, radios or other types of music devices playing, phones ringing, doorbells chiming, etc.
  • Animal noises: Dogs barking, cats meowing, birds chirping, lions roaring, bears growling, etc.
  • House noises: stairs creaking, door hinges squeaking, glass shattering, electricity cutting out, lumber splintering, door locks engaging, water pipes groaning, etc.
  • Water sounds: water dripping or pouring, waves crashing, rivers rushing over rocks
  • Echoes: echoing, fading or reverberating of sounds
  • The list goes on and on . . .

When NOT to Capitalize:

But here is a small list of sounds that would NOT be Capitalized if made on screen, but WOULD BE Capitalized if made offscreen:

  • Characters making noises with their mouths: laughing, coughing, screaming, crying, humming, whistling, sneezing, breathing heavy, etc.
  • Characters making noises with use of body parts: snapping their fingers, tapping a pencil, clicking their heels, tapping their feet, kicking or hitting a wall, knocking on doors, clapping their hands, hammering a nail, hitting another character, slamming doors, etc.
  • Crowds of people making noise: applauding, cheering, protesting, singing, chanting, booing, laughing, etc.

Special Situations:

Here are a few on screen situations in which whether or not to Capitalize the sound might not be completely clear:

  • Musicians Playing Instruments: If an orchestra or band, DO NOT Capitalize. If an individual person, go ahead and Capitalize as the actor may not have the ability to ACTUALLY play the instrument, and the music might need to be added in editing.
  • Babies or Very Young Children: Capitalize, as they likely won't perform on cue.
  • Sports players: such as the dribbling of basketballs or squeaking of basketball shoes on screen, DO NOT Capitalize.
  • Ghosts or Spirits moaning or rattling chains, etc.: DO NOT Capitalize if the ghost on screen is clearly a person in form that can be played by an actor. However, if it is just a hazy, unformed cloud, then Capitalize sounds.

The Word "Sound":

Whenever possible, avoid Capitalizing the word "sound" in a Direction paragraph to cue a sound effect. This example is INCORRECT:

However these examples are CORRECT:

Of the three, the middle example is preferable. The bottom example is technically correct, however it should ONLY be used as a last resort when no other sound descriptor works.


In the old days, the term SFX. (that's SFX followed by a period) would precede a sound cue. It would have looked something like this:

SFX. stood for "Sound Effect" and was not to be confused (although it often was) with its siblings that cued special effects (FX. and SPFX.).

DO NOT use SFX. today to cue a sound effect. Just Capitalize the sound based on the rules on this page.