Absolutely plan ahead! There are ASL interpreters, but only in specific parks on specific days. So contact them ahead of time to know where the interpreters will be when you're there. Also take advantage of acommodations such as the hand-held captioning device and rear window captioning at certain attractions.
and never be afraid to ask a cast member for acommodations or assistance. Their job is to make your experience equally as enjoyable as for a hearing
child.