Sign Language Interpretation
Some Deaf people whose first language is British Sign Language (BSL) may not be able to access captions. This is because captions rely on the reader having a good understanding of English and BSL is unrelated to English or other spoken languages.
A Sign Language Interpreter makes the spoken or sung word accessible for this audience. Usually, the interpreter will stand to one side of the stage and interpret whatever is being sung or spoken into Sign Language. In some shows, there may be two interpreters sharing out the characters between them. The interpreter needs to be well lit and there needs to be clear sight lines to the interpreter from the audience members using them.
Some productions use a Sign Language interpreter within the show itself, with the interpreter moving about the stage along with the other characters, but this is still fairly uncommon.