SubtitleMedic

What are SDH subtitles, and how are they different from CC?

Updated October 18, 2026

SDH stands for Subtitles for the Deaf and Hard of hearing. Besides the dialogue, SDH subtitles describe everything else a viewer needs from the soundtrack: sounds, music, and who is speaking when it isn’t obvious. They exist so that someone who can’t hear the film can still follow it.

On streaming services and Blu-ray discs you see them as a separate track, labelled “English [SDH]” or “English (CC)”. Subtitle files downloaded from the internet carry the same thing in their name: .sdh.srt, .hi.srt or simply “HI”.

What SDH subtitles contain

An SDH file has all the dialogue of a regular subtitle, plus lines like these:

12
00:04:10,300 --> 00:04:12,100
[door creaks open]

13
00:04:12,500 --> 00:04:15,000
MARA: Who's there?
(whispering) Stay behind me.

14
00:04:16,200 --> 00:04:19,800
♪ soft piano music ♪
  • Sound descriptions in square brackets or parentheses: [door creaks open], (phone buzzing), [speaking French].
  • Speaker names, usually in capitals before a colon (MARA:), used when the speaker is off screen or several people talk at once.
  • Manner of speaking: (whispering), (sarcastically), [shouting].
  • Music and lyrics, marked with ♪ notes, from a description of the score to every word of a song.

SDH, CC and regular subtitles

The three terms are often used as if they meant the same thing. They don’t quite.

Regular subtitles assume you can hear. They give only the dialogue, often as a translation. Some are “forced” subtitles that only appear for a sign or a line in another language.

Closed captions (CC) come from North American television. They were carried inside the broadcast signal, using a standard known as CEA-608, and switched on by the viewer, which is what “closed” means. Classic captions are white text on a black box, can appear anywhere on screen, and describe sounds just like SDH.

SDH brings the same information to formats that don’t support broadcast captions, such as DVD, Blu-ray and streaming. It looks like ordinary subtitles, with the same font and placement, but carries the sound descriptions and speaker names of captions.

In practice, today’s streaming services label their caption tracks as SDH or CC and both contain the same kind of information. When you download a subtitle file, “SDH”, “HI” and “CC” all mean: this file describes sounds.

Why people remove SDH from subtitles

SDH subtitles are essential for deaf and hard-of-hearing viewers, and many hearing viewers like them too, for noisy rooms or mumbled dialogue. But often the SDH version is simply the only English file available for a film, and for someone who hears the soundtrack the extra lines get in the way:

  • Quiet scenes fill up with [wind howling] and (sighs).
  • Two-line subtitles become three or four, covering more of the picture.
  • Song lyrics run across the screen during a montage.
  • In a dual-language file, made with Merge Two Subtitles, there is no room for them at all.
  • In a transcript, the descriptions break up the text.

How to remove SDH from a subtitle file

You could delete the lines by hand in a text editor, but a film has hundreds of them. Remove SDH from Subtitles does it in one pass:

  1. Open the .srt, .vtt, .ass, .sbv or .sub file. It is read in your browser and never uploaded.
  2. Square brackets, parentheses and music lines are removed straight away. Turn on Speaker names to also take out MARA: labels.
  3. Check the preview, where every removed piece is struck through, then download the file in its original format.

A subtitle that held nothing but a description, such as [thunder], is removed completely, and the timing of every other line stays exactly as it was.

If the file also carries ad lines like “Subtitles by …” or leftover tags, Subtitle Cleaner removes those along with the SDH in one go. For tags alone, such as <font color> or {\an8}, use Remove Formatting from Subtitles.

Tips

Keep the original. If someone in your home relies on captions, keep the SDH file next to the cleaned one. Players can load both and let you switch.

Watch the parentheses. Some subtitlers put spoken asides in parentheses. If the preview shows real dialogue disappearing, turn the parentheses switch off and keep only the square brackets.

Name the file so players find it. Save the cleaned file with the video’s name, for example movie.en.srt, and your player will load it by itself. More on naming in What is an SRT file?

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