A transcript is essentially a text-based document that displays voice and sound information. Conversations, speaker identities, and nonverbal sound effects such as a doorbell ringing would all be included in the body of a transcript. A transcript can also include visual images that are linked to the audio file, such as paper documents displayed over images on a digital recorder. The transcript form allows readers to read through the dialogue aloud, which helps them understand the flow of conversation and makes it easier to follow the narrative. Transcriptions are commonly used by students to review material that was covered in class or for professionals to check their work. Transcripts can be created in several different formats depending on the requirements of the user. Commonly used formats include typed manuscripts with page numbers and dates, handwritten notes with speaker labels, and tape transcripts that display each word as it is spoken. Video tapes can also be converted into transcripts by professional transcriptionists. These recordings can then be searched using keyword tags to find specific conversations or segments within the video. Video transcripts are useful because they allow viewers to listen to exactly what was said during certain scenes or conversations. This can help them understand the context of remarks made by speakers not visible on camera, for example when a teacher is speaking from behind their desk but says something relevant to the class anyway.