Interpreters are accurate

One of the rules of conduct interpreters follow is that they convey their message accurately and impartially, conveying the true meaning of what a person is saying. Interpreters are required to interpret everything they hear, including background noises. Deaf people should be able to know everything that is audible, even their boss’s side discussion on a cell phone with their partner about what to have for dinner during a staff meeting break.

http://carolafinch.hubpages.com/hub/Characteristics-of-Effective-Sign-Language-Interpreters 11092015