A high-caliber cast of deaf and hearing actors at the Martha’s Vineyard Playhouse is bringing to life the seldom-told story of Chilmark in the 19th century, when hereditary deafness was so widespread that just about everyone in town spoke the local sign language as a matter of course.

Set in 1885 and simply titled Chilmark, the play by Catherine Rush takes place in a community where deafness was not a disability but a family trait — with an added bonus that deaf children could go to special schools off-Island, where they often learned faster than their hearing playmates at home.

Ms. Rush also directs the playhouse production, which stars deaf actor Erin Rosenfeld as young Anne Lambert, the well-educated daughter of a widowed storekeeper.

Ms. Rosenfeld is known for her appearances with children’s-video star Ms. Rachel, her work on the New York stage and her advocacy for deaf inclusion.

The show’s other deaf character, town secretary and retired whaler Capt. Nate Smith, is played by stage and screen actor Robert Schleifer. A storyteller with a strong sense of dignity, Captain Smith has two sons, one deaf and one hearing, who now are at risk of being separated by the deaf boy’s schooling.

Erik Baker and Jane E. MacDonald play two hearing Chilmarkers, who sign every time they speak — and can’t always remember who else can hear and who can’t, in a town where one in every 25 people was born deaf. In Squibnocket, reportedly, the rate was higher: 15 out of 60 residents in 1854.

As Anne’s father, Ezra Lambert, and widowed neighbor Mrs. Athearn, Mr. Baker and Ms. MacDonald help carry the narrative as they respond to — but only sometimes translate — the deaf characters’ signed speech.

The play opens with a dramatically signed sea story told by Captain Smith, one of many wordlessly compelling moments during the two-hour play.

Anne Lambert’s goal is to establish a school in Chilmark where deaf and hearing children can learn together, without anyone having to leave their home.

Sarah Hall, a well-heeled woman from the mainland, offers funding to start the local school, but just as Anne’s hopes are soaring, her would-be benefactor reveals that sign language would be banned, citing the prominent inventor and scholar of hereditary deafness Alexander Graham Bell.

The Chilmarkers send Ms. Hall packing, but not before she’s given them a disturbing taste of how the deaf are viewed in 1880s America.

“Manual communication doesn’t fully utilize the brain,” she tells the scandalized townspeople. “A man who can’t speak is not using his brain correctly.”

As a result, Miss Hall says, deaf people who are mute can never rise above laborer status, while those who learn speech and lip-reading may have their pick of jobs.

It’s the first time the up-Islanders have heard of this doctrine, but Miss Hall dismisses the locals’ argument that deafness isn’t holding anyone back in Chilmark.

“This Island is an aberration,” she says.

Anne’s disillusionment, as she hears herself and her neighbors described as essentially subhuman, is plain on Ms. Rosenfeld’s expressive face. So is her character’s deep scorn at Miss Hall’s inability to converse in sign language, while insisting that Anne is the limited one because she cannot speak.

After Miss Hall takes her leave, both Anne and Captain Smith must reckon with the disturbing suggestions left in the visitor’s wake — a struggle that ruptures the older man’s friendship with Ezra and leads Anne to make an extraordinary appeal.

As the well-intentioned Miss Hall — not quite a villain, but a dangerous dupe — Liz Michael Hartford returns to the role she played when Chilmark premiered at the playhouse in 2018.

Ms. Rush has been working for well over a decade on the play, which she first began writing with her husband, deaf actor Adrian Blue.

She has brought multiple versions to the playhouse over the years. After a 2004 reading by elementary school children under the title A Nice Place to Live, Ms. Rush and Mr. Blue continued to develop the play, which returned to the playhouse in 2006 as This Island Alone and in 2018 under its current title, with Ms. Rush the sole author and director.