More than dialogue translation
A hearing viewer receives information from voices, sound effects, music and the way audio is positioned within a scene.
Accessible subtitles may need to represent some of that information in text so that viewers who cannot hear the soundtrack can still follow what is happening.
This can include speaker identification, relevant sound effects, music information and other audio cues that contribute to comprehension.
The precise conventions depend on the client and platform specification.
SDH and captions
SDH is commonly used for subtitle files designed for deaf and hard-of-hearing viewers, particularly in film and streaming contexts.
The word captions is especially common in North America, while other markets often use subtitles more broadly for both same-language and translated timed text.
Closed captions usually refers to a track the viewer can turn on or off, whereas open captions are permanently visible in the image.
Because terminology can vary, we focus first on the functional requirement and the delivery specification rather than assuming that a label alone defines the file.
Speaker identification
When the speaker is not visually obvious, the subtitle may need to identify who is talking.
This can happen with off-screen voices, phone calls, interviews, panels and scenes containing several speakers.
The way speakers are identified should follow the relevant accessibility style or client requirements.
A character list or participant list helps maintain consistent naming throughout the programme.
Sound effects
Not every sound needs to be written on screen.
The relevant question is whether the sound contributes information that the viewer needs in order to understand the action, mood or narrative.
A door slam, alarm, phone ringing, crowd reaction or other sound may be important in one scene and irrelevant in another.
Accessible subtitle creation therefore requires editorial judgement as well as technical timing.
Music
Music can contribute to meaning even when no lyrics are sung.
A specification may require certain musical information to be identified when it affects the viewer’s understanding of the scene.
Songs with plot-relevant lyrics may require a different treatment from background music.
We follow the agreed rules for the project rather than applying a single generic notation to every production.
Same-language accessible subtitles
Accessible timed text can be produced in the same language as the soundtrack.
For example, Spanish audio may need Spanish accessible subtitles, or Basque audio may require an accessible Basque track.
The work can start from an existing subtitle file, a transcript or directly from the audiovisual material.
Translated SDH
Some projects require both translation and accessibility information.
This is not always achieved by simply translating an existing standard subtitle file because the target version may also need speaker and sound information according to the destination specification.
We can assess whether the client has a suitable source accessibility template or whether additional work is needed.
Accessibility in the languages of Spain
We can work with Spanish, Basque, Catalan, Valencian and Galician accessible subtitles when the project requires them, as well as other international languages.
Our Spanish page specifically addresses projects governed by UNE 153010 requirements. For international work, the client or destination platform specification should be identified because the expected conventions may differ.
Timing and readability
Accessible subtitles must remain readable while carrying additional information.
Speaker labels and sound descriptions consume screen space, so timing, segmentation and wording need careful control.
The objective is to provide the information the viewer needs without turning every subtitle event into an overloaded block of text.
Broadcast, streaming and online video
Accessibility requirements differ between broadcasters, streaming platforms, web players and other delivery environments.
The technical file format can also vary.
We therefore ask clients to provide any platform, broadcaster or distributor specification that applies before production begins.
File formats
Accessible timed text can be delivered in formats such as WebVTT, TTML, SCC, SRT or others depending on the target environment.
WebVTT can carry captions and subtitles for web video, while professional broadcast and platform workflows may require richer timed-text specifications.
The file type should be chosen according to the destination rather than by habit.
Frequently asked questions
What is the difference between subtitles and captions?
Usage varies by market. In many US contexts, captions are same-language accessible timed text, while subtitles are associated with translation. In other countries the word subtitles covers a broader range of timed-text services. We define the actual accessibility and technical requirements before work starts.
What does SDH include?
SDH can include dialogue plus information such as speaker identification and relevant sounds or music. The exact conventions depend on the specification used for the production.
Do you provide closed captions?
Yes, where the target platform and required file specification support that deliverable. We need to know the destination in order to confirm the appropriate workflow and format.
Can you provide accessible subtitles in Basque or Catalan?
Yes. We can work with the languages of Spain as well as other international languages, subject to the required accessibility specification.
Can an ordinary subtitle file be converted into SDH automatically?
Not reliably as a complete process. An ordinary subtitle file may not contain speaker or sound information, so the audiovisual material usually needs to be reviewed.
Which format do accessible subtitles use?
It depends on the platform. WebVTT, TTML, SCC, SRT and other formats may be used in different environments.