For any additional questions or to learn more about alternative text best practices, contact the
Instructional Accessibility Group at InstructionalAccessibility@msudenver.edu
Best Practices for Writing Closed Captions
Captions are the text alternative to the audio component of any video. Captions are different than
subtitles as subtitles only display the spoken dialogue. Only providing subtitles can eliminate a lot
of important content from a video making it hard to access. Captions are much more
comprehensive to provide the full experience of the video content. This guide will cover the best
practices for writing captions.
Caption Guidelines:
1. Captions need to match the timing while staying up long enough to be read.
2. Captions need proper grammar and conventions to help convey meaning.
3. Do not exceed 30 characters per line.
4. Do not have more than two lines on the screen at a time.
When to Caption:
The best rule of thumb is to caption everything that holds value for someone with full access to the
soundtrack; this sometimes includes a lack of sound. The following list will identify moments you
will need to add captions:
1. Important Sounds: scenes with multiple sounds (e.g. a conversation in public place) can be
chaotic.
a. Caption the most prominent sound or the sound that offers the most value.
2. Dialogue: speakers must always be captioned.
a. Identify speakers and tones when they cannot be inferred.
b. Caption verbal/oral bridges (e.g. “um” and “uh”) unless they hold no value (i.e.
during a live speech).
3. Sound Effects: sound effects almost always need to be captioned at every iteration.
a. An exception would be a sound repeated at regular intervals (e.g. footsteps)
especially when the sounds can be inferred (i.e. the feet can be seen walking), and
other sounds take precedent.
4. Music/Background Noise: music and other noise is usually added to build mood or a tone
and needs to always be captioned.
5. Lack of Sound: silence can be just as valuable as sound.
a. Identify moments when the sound cuts or fades out.
b. Identify moments when speakers are not heard (i.e. a character is moving their lips
without speaking).
6. Muffled/Distorted Sound: much like lack of sound, muffled and distorted sounds need to
be identified.
For any additional questions or to learn more about alternative text best practices, contact the
Instructional Accessibility Group at InstructionalAccessibility@msudenver.edu
What to Write:
The hardest part about captioning is deciding what to write. Except for dialogue, the sounds of a
video can be hard to describe effectively. The following list will give you tips on what to write when
creating captions:
1. General Rule: caption all sound effects in brackets [ ] to separate them from dialogue.
2. Dialogue: write exactly what the speakers are saying (see 2b above for an exception).
a. Use italics or Write “off-screen”/“VO” (for Voice Over) when the speaker cannot be
seen.
b. Identify speakers by name or role (e.g. Man #1) when it is not visually clear who is
speaking.
c. Identify hard to hear dialogue as “unintelligible.”
3. Sound Effects: always name the object making the sound (e.g. “[engine revving]” or “[clock
ticking]”) as it is what makes the sound that usually creates meaning to those with access to
the soundtrack.
a. Avoid using descriptive onomatopoeias as they can be subjective or valueless
4. Music/Background Noise:
a. Music: name the song and artist or the instrument and identify with music notes
(keyboard shortcut varies by program).
i. If either is unclear, do your best to describe the tone/mood of the music (e.g.
“somber music” or “eerie music”).
b. Background Noise: identify the noise (e.g. “[crowd cheering]” or “[birds chirping]”).
5. Lack of Sound:
a. Depending on the context, it may be appropriate to establish that a sound stopped
(e.g. “[clapping stops]”) or to simply identify the sudden silence (e.g. “[silence]”)
i. A combination of both may be the best
b. Always identify when a sound fades away slowly
c. Write “[mouths words]” or “[inaudible]” if a character is moving their lips without
speaking.
6. Muffled/Distorted Sound: identify the type of distortion (e.g. “[muffled]” “[echoing]”)
a. Identify when it fades or ends; you can also identify that the sound is “normal.”
Remember, if it holds value for someone with access to the full soundtrack, you need to caption it.
