SDH subtitles are a mix of subtitles and closed captions developed for people with hearing impairments. The acronym SDH stands for Subtitles for the Deaf and Hard of Hearing. This type of subtitles can be in the video's original language because it contains non-dialogue audio sound effects and speaker identification. Therefore, SDH subtitles are created in a way that assumes the viewer is unable to hear the audio. In addition, SDH subtitles emulate closed captions on digital connections like HDMI, as they do not support closed captions.