LoginTry it Free

What Are SDH Subtitles?

SDH stands for Subtitles for the Deaf and Hard of Hearing. Besides the dialogue, SDH subtitles name off-screen speakers and describe sounds that matter — [door slams], [phone buzzing], [tense music] — so the video makes sense without audio. Streaming services label them, for example, English [SDH].

Example
12
00:03:14,200 --> 00:03:16,800
[phone buzzing]

13
00:03:17,000 --> 00:03:19,500
MARK: Don't answer that.

SDH vs regular subtitles

Regular subtitles assume you can hear and only translate or transcribe speech. SDH adds everything a hearing viewer gets from the soundtrack: who is talking, sound effects, music and tone.

SDH vs closed captions

The content is similar. The difference is mostly technical and regional: closed captions come from broadcast standards with their own look, while SDH uses subtitle formats and styling, which is why it appears on streaming services and discs.

Writing good SDH

Describe sounds briefly in square brackets, name speakers only when it isn't obvious who is talking, and skip sounds that add nothing to the story. Song lyrics are usually shown in italics or with a music note.

Questions

What does [SDH] mean on Netflix or a Blu-ray?

That the subtitle track includes sound descriptions and speaker names for deaf and hard-of-hearing viewers.

Are SDH subtitles required by law?

Accessibility rules such as the ADA, WCAG and the European Accessibility Act require captions for many videos; SDH-style subtitles are one way to meet them.

Is SDH only in English?

No. Any language can have an SDH track.

Read more

Related terms

  • Open captions

    Open captions are captions burned into the video itself, as part of the picture. They are always visible, look the same on every player and platform, and cannot be switched off — unlike closed captions, which come as a separate track the viewer can turn on or off.

  • Forced subtitles

    Forced subtitles appear even when the viewer has subtitles turned off. They cover only what a viewer in the film's language would otherwise miss: dialogue in another language, signs, letters and on-screen text. Streaming services call them forced narrative subtitles.

  • Speaker diarization

    Speaker diarization is the step in speech recognition that works out who spoke when. It splits a recording into segments by voice and labels them Speaker 1, Speaker 2 and so on, so an interview or meeting transcript shows each person's turns instead of one block of text.

Updated: