The series focuses on two families who discovered their teenage daughters were switched at birth. John (D.W. Moffett) and Kathryn (Lea Thompson) raised Bay (Vanessa Marano); single mom Regina (Constance Marie) raised Daphne (Katie LeClerc). When the truth comes out, the two families deal with the ramifications.
"I pitched that," Weiss said. "They bought that. And then, after I wrote a whole outline, the network said, 'Let's up the stakes. What can we do to make it even more interesting?'
"I said, 'What if Daphne's deaf?' "
It's both startling and completely matter-of-fact. It's just part of the world these characters inhabit.
"I don't want to be too treacly that's a rule," Weiss said. "I don't want to be too preachy."
The deaf characters aren't perfect. Far from it. They're regular teens who can't hear.
Daphne isn't the only deaf character. Her friends and classmates play an integral part in the storylines including Monday's all-ASL episode (9 p.m. ABC Family) in which the teens protest the closing of their school for the deaf.
It fits Weiss' stated goal of telling "universal" stories "that you can relate to whether you're deaf or not."
LeClerc isn't deaf; she is hard of hearing. She has Ménière's disease, an inner-ear disorder that affects hearing and balance.
But other actors, including Sean Berdy (who plays Daphne's best friend, Emmet), are deaf. And he never expected to find a role like the one he has on "Switched."
"I had never seen another show like this," said Berdy, 19, speaking through an interpreter. "Other shows seem to not do a lot of research on deaf people and their characters.
"This show is different because we value the authenticity of ASL and the deaf characters. And so the deaf background and the culture everything is taken into consideration."
Nobody claims "Switched at Birth" is altogether authentic. Accommodations are made for TV, like when Daphne signs and speaks simultaneously. And the deaf actors have to slow down their signing so they don't out-run the captions, captions most viewers will need on Monday.
"Otherwise, I would sign like a ninja," Berdy said with a laugh.
Scott D. Pierce covers television for The Salt Lake Tribune. Email him at firstname.lastname@example.org; follow him on Twitter @ScottDPierce.