“Closed captioning is widely but not unfailingly available in theaters; that should improve by next summer, when all theaters showing digital movies must comply with a new federal rule under the Americans With Disabilities Act. As for performers, ask people to name deaf movie actors — or films about deaf people starring deaf people — and you’ll probably get exactly one name and title: Marlee Matlin, who won an Oscar for her turn in “Children of a Lesser God” 30 years ago. Then, crickets.”