Slightly OT here considering we are talking about terps and voicing, but realize that most ASL/English terps do most of their terping into ASL, which is most terps second language! This produces lower quality interpretations than if people are translating into their native language generally. Really, from what I have been taught and is logically true--- non-native signers that are interpreters actually voice better than they sign! (Scary thought)... For those who don't believe that, this about this, we can hear ourselves voicing and get immediate feedback, but with signing we can't- many times new interpreters end up signing "all the words" but the meaning doesn't get conveyed...