
the WDW website recommends contacting them at least 2 weeks in advance to confirm dates and times for interpretation.
Some posters have just shown up at the park that was listed as having interpreters that day and found they had missed the only interpreted performances of a show they wanted to see.
Cheshire Figment posted s link to the WDW Guest Relations page about services for guests with hearing impairments. You can also find a link to that page in post #3 of the disABILITIES FAQs thread. That post also includes some links to articles about services.