Direct your conversation to the hearing impaired student, not the interpreter. Interpreters should not participate in the conversation. Expect the sign language interpreter to sign everything said by yourself, the student, and others in the class. Try to give as much advance notice as possible for special events so that sufficient time is available to secure a sign language interpreter. It is the responsibility of the student or the faculty member to make those arrangements, not the interpreter.
Interpreters have to finger spell new words.
Lists of vocabulary specific to your class given to the interpreter in advance can greatly facilitate communication for the hearing impaired student. Do not hesitate to ask hearing impaired students to repeat what they have said if you cannot understand them. If you still have difficulty understanding, then you may suggest they write their comments down if an interpreter is unavailable. Make sure that a hearing impaired student is made to feel comfortable about contributing to class discussion by discussing possible strategies with the student. Additional time for testing may be required for students with significant hearing loss who use American Sign Language.