SDH commonly means subtitles for Deaf and hard-of-hearing viewers. Such tracks usually include dialogue plus useful sound cues and speaker information. Exact coverage varies, so the label is a helpful starting point rather than proof that every important sound has been represented accurately.
Listen and read a revealing scene
A scene with an off-screen speaker, a phone ringing or music changing can show how a track handles non-dialogue information. A dialogue-only passage does not reveal the difference clearly. If watching without sound, choose the track that lets the scene make sense rather than simply the shortest language label.
Use readable presentation
Caption size, contrast and placement affect usefulness as much as availability. Select a style that remains legible over both bright and dark images without covering essential action. Player style controls may apply only to separate text tracks; they cannot restyle captions already burned into the picture.
Report specific omissions
If a track leaves out an important sound or labels the wrong speaker, note the title, language and playback time. This gives the provider something concrete to review. A player’s accessibility preference can choose an SDH track when present, but it cannot create a professionally prepared track for a programme that lacks one.