Oscar-winning actress Marlee Matlin is usually the only Deaf person on a set. Matlin came to a big realization when making “CODA,” a breakthrough film featuring Deaf actors. “I’m the one typically going to my trailer by myself, and it’s just me and my interpreter. But in all honesty, I never thought of it until I got on the set of ‘CODA’ and realized there’s a whole different world out there I’ve been missing all this time,” Matlin says. “Realizing that here I am, on the set of ‘CODA,’ in my element at lunch time, because everybody is signing. The hearing crew — they’re signing, there’s Deaf cast members, and most importantly, our director learned sign language.” Director Siân Heder and Matlin tell KCRW about making their family drama “CODA,” which scored a record-breaking deal at Sundance last year and has already made history. For the first time, a film featuring a Deaf cast has been nominated for Outstanding Performance at the SAG Awards.