Interpreters interpret faithfully
Interpreters are required give their best interpretation of what is being signed or said. They also interpret any relevant noises. They don’t edit or add their own embellishments. If the speaker is animated and enthusiastic, the interpreter will mirror that. If a speaker is boring and dry, the interpreter is also boring.
http://carolafinch.hubpages.com/hub/Characteristics-of-Effective-Sign-Language-Interpreters 11092015