Transcription Services

Subtitling, captions and SDH

Accurate, well-timed subtitles in 300+ languages for broadcast, streaming and online video.

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Subtitling adds timed text to a video so viewers can read what is being said. It might be a translation for an audience that does not speak the language, same-language captions, or SDH that also describes important sound for deaf and hard-of-hearing viewers. Prism Linguistics produces all three, in more than 300 languages, for UK broadcast, streaming and online content.

Good subtitling is quiet craft. The text has to be accurate, broken into sensible lines, and on screen long enough to read but not so long it lags the picture. When it is done well you barely notice it. When it is done badly, it is all anyone notices.

Subtitles, captions and SDH: knowing which you need

The three terms get used loosely, so it is worth being clear.

Subtitles usually means a translation of the dialogue, for viewers who do not speak the original language. Closed captions are a same-language text of the dialogue, which viewers can switch on or off. SDH, subtitles for the deaf and hard of hearing, include the dialogue and the sound that carries meaning: a doorbell, music starting, or who is speaking when they are off screen.

Which you need depends on your audience. A video for an international launch needs translated subtitles. A UK training video needs captions, and SDH if accessibility matters, which under the Equality Act it usually should. Tell us the audience and we will recommend the right one.

Why it is more than translating a transcript

Translated subtitles are not just a transcript run through translation. A viewer can only read so fast, and a subtitle line can only be so long. The subtitler condenses the meaning so it fits the reading speed, decides where each subtitle starts and ends, and times it to the speech. That is a skill in itself, and it is why a properly subtitled video feels effortless to watch and an auto-captioned one does not.

What we deliver

Subtitling for every kind of video

Translated subtitles

Subtitles in 300+ languages, condensed and timed by subtitlers, not just translated from a transcript.

Closed captions

Same-language captions of the dialogue, switchable on or off, for clarity and reach.

SDH

Subtitles for deaf and hard-of-hearing viewers, including speaker IDs and meaningful sound.

Broadcast subtitling

Subtitles produced to UK broadcast conventions, in line with Ofcom guidance and broadcaster style guides.

Subtitle files

SRT, VTT, SBV, TTML, EBU-STL and more, ready for your platform, or burned into the video on request.

Online and social

Captions for YouTube, Vimeo and social video, where most viewers watch with the sound off.

Questions people ask

Subtitling FAQs

What is the difference between subtitles, captions and SDH?
Subtitles usually mean a translation of the dialogue for viewers who do not speak the language. Closed captions are same-language text of the dialogue. SDH, subtitles for the deaf and hard of hearing, include the dialogue plus important non-speech sound, such as a phone ringing or who is speaking off screen. We produce all three.
Do you provide translated subtitles in other languages?
Yes. We subtitle video into more than 300 languages. A translator who understands subtitling works to the reading-speed and line-length limits, so the meaning lands and viewers still have time to read each line. This is more than translating a transcript: subtitles have to be condensed to be readable.
What subtitle file formats do you deliver?
We deliver SRT, VTT, SBV, TTML, EBU-STL and other common formats, so the files drop straight into your player, platform or editing software. If you want the subtitles burned into the video itself, we can arrange that too.
Can you meet broadcast subtitling standards?
Yes. We work to the timing, positioning and reading-speed conventions expected for UK broadcast, in line with Ofcom guidance on subtitle quality. Tell us the broadcaster or platform and we will follow its style guide.
Why not just use automatic captions?
Automatic captions are a useful starting point, but they misjudge names, technical terms, accents and punctuation, and they do not break lines or time them for comfortable reading. For anything public-facing or broadcast, the difference between auto-captions and properly produced subtitles is obvious to viewers, and especially to those who rely on them.

Need your video subtitled?

Send us the footage and tell us the languages and where it will be shown. We will quote and recommend the right kind of subtitles.

Get a quote Call +44 (0) 20 3880 6688