Insist That the Interpreter:
Speak in the first person.
Remain in close proximity when you are speaking.
Carry a notepad and take notes, as needed.
Ask questions when not sure of a term, phrase, concept, acronym, etc.
Project clearly and mirror both your vocal stresses and overall tone.
Refrain from becoming engaged in a tangent dialogue with your audience/interlocutor(s), nor becoming an advocate or mediator in the dialogue; ideally, the interpreter should remain invisible.