I thought of something else.
Even if the class is 100% voice off, be sure that the disabilities office and instructor know that if a hearing non-signer comes to make an announcement to the class, you will need an interpreter or other accommodations.
It does happen. Public safety, visiting accreditation committee, media resources rep, other administrative people do come to the classrooms to make announcements. If it's a scheduled visit, accommodations should be provided. Obviously, if it's an emergency, that's a different situation.
Students are also entitled to accommodations when they go to the book store, the library, financial aid office, job fairs, field trips, and public safety. It's up to the student to decide whether or not those accommodations are necessary, and the student should be reasonable about allowing enough advance notice.