That's why she was so excited for her TV character, Lieutenant Kate Dixon, to use American Sign Language (ASL) on the Oct. 6 episode of the NBC crime drama, during which she used it to communicate with a young girl involved in a dangerous case.
"It was really meaningful for me," she exclusively told E! News at New York Women in Communications 52nd Annual Matrix Awards on Oct. 26, at which she presented her friend and fellow actress Marlee Matlin with The Matrix Award. "I had asked them to incorporate some deaf characters, and I know that SVU is also doing a storyline with some deaf characters."
In doing so, Manheim hopes that more shows and movies continue to reflect the diversity of real life, adding, "Not just diverse in color, but diverse in bodies."
"We need to have disabled people all over the place," she continued, "people in wheelchairs and blind people and people who have cerebral palsy and deaf people."
At the end of the day, the actress believes that "people should be able to look on television and see themselves, a role model, to be emulated on the screen."
The 61-year-old shared she first learned ASL to help her get into college after failing French and Spanish classes in high school. And it's because of ASL that she became close friends with Matlin, who made history as the first deaf performer to win an Oscar in 1987.
"I'm a sign language interpreter, so I was swirling around in the deaf community and fangirling over her," Manheim recalled. "I finally got an occasion to meet her and stalked her and everything that you do when you can't believe you've met somebody so amazing."
The two went on to work together on the TV series The Practice, as well as the 2015 Broadway revival of the musical Spring Awakening.
Law & Order airs Thursdays at 8 p.m. on NBC.
(E! and NBC are both part of the NBCUniversal family.)