The Best of Both Worlds
SDH, which stands for Subtitles for the Deaf and Hard of Hearing, is a hybrid format designed to make content accessible to those who cannot understand the audio, either because they are deaf/hard of hearing or because they do not speak the language of the film. It effectively merges the purpose of standard subtitles with the comprehensiveness of closed captions, ensuring no information is lost for the viewer.
Combining Subtitles and Captions
To understand SDH, it’s best to see how it borrows from both formats:
- Like Subtitles: A standard subtitle track is created for foreign language translation. It assumes the viewer can hear the audio but can’t understand the language, so it only transcribes the dialogue. SDH files are formatted and delivered in the same way as subtitle files (e.g., as an .srt or .vtt file), meaning they can be selected from a menu on a Blu-ray or streaming service.
- Like Captions: A closed caption track is created for accessibility. It assumes the viewer cannot hear the audio at all, so it transcribes both dialogue and essential non-speech sounds (like
[door slams]).
SDH combines these two functions. It is a subtitle track that includes the non-speech elements of a caption track.
The Primary Use Case: Foreign Language Accessibility
The most common scenario where you will encounter an SDH track is when watching a foreign-language film. Let’s say you are an English-speaking person who is also deaf, and you are watching a French film on a streaming service. You would be presented with several text options:
- English Subtitles: This track would only translate the French dialogue into English text. You would miss out on crucial sound effects and music cues.
- French Closed Captions: This track would include all the audio information, but it would be written in French, which you do not understand.
- English SDH: This is the perfect solution. It provides the English translation of the dialogue and includes the descriptive, non-speech information from the caption track (e.g.,
[ominous music swells]). This ensures you have the exact same full-spectrum understanding of the film’s auditory world as a hearing person who speaks French.
Because of their robust nature, SDH tracks are often used as the default ‘English’ track on streaming services and Blu-rays even for English-language films, as they provide a comprehensive experience for all users who choose to enable them.