Professors now must prove mastery of sign language to get tenure. Students, too, are expected to sign. In a campuswide e-mail last fall, Hurwitz wrote: “Everyone on campus — no matter his or her signing level — should make every effort to communicate in sign language when in public areas on campus.”

But upholding that standard is increasingly difficult on a campus where nearly half of the freshmen now come from mainstream high schools and dozens arrive not knowing how to sign. To help them, university leaders last year created a six-week crash course for 46 new signers, an orientation to Gallaudet and to the deaf world.

An explosive opinion piece in the school newspaper last fall decried the rise of non-signers on campus and the potential demise of “the one deaf space we can have in this country.”

Some students agree. Others favor a more patient approach to new signers.

Leila Hanaumi, a 21-year-old senior, attended a deaf school and knew Gallaudet and its history when she enrolled. She’s one of a few on campus who fully appreciate how much the school has improved; at an institution where the population turns over every few years, memories are short.

“In my class, we have the highest retention rate in I don’t know how long,” she said. Most of her class will graduate within five years, “and that’s pretty much unheard of.”

The university’s future may depend on reaching further into the mainstream of American education. Gallaudet recruiters have tripled the number of annual visits to public schools since 2006.

A trip might focus on one or two students who know nothing of Gallaudet. Charity Reedy-Hines, the chief recruiter, recalled a recent visit to a public high school in Mississippi where recruiters met with two deaf students.

“Both of them had never met another person like themselves,” she said. “They hadn’t even met each other.”