Former vice president Joe Biden on Wednesday pushed college students to work to combat sexual assault, by intervening if they see a questionable situation and speaking up against so-called locker room talk.

“Change the culture,” he told a crowd at George Mason University in Fairfax, Va. “You can do it.”

Biden was appearing at Mason, a public university with about 35,000 students, as part of an event for “It’s On Us,” a campaign focused on stopping sexual assault on college campuses. The effort launched a few years ago, during the Obama administration.

“College campuses are communities,” Biden said. “And the place where people’s attitudes are affected, changed, altered, impacted, are within communities.”

Biden at times spoke in personal terms, referencing lessons his own father taught him. He also targeted his remarks specifically at men in the audience, saying that if a woman is “dead drunk,” she cannot consent. “You are raping her,” he said. He also said that if men heard conversations that were inappropriate, they should say something.

“You’ve got to speak up,” his voice louder. “You cannot let that kind of talk be bred on the college campus. You’ve got to do what I’ve done, what my father taught me. Turn and say, you’re a horse’s tail. Only a little more graphic.”

Before the former vice president took the stage, the crowd, comprised mostly of students, heard from other speakers, including a survivor. That student, Emiko Ellis, 20, a microbiology major from Virginia Beach, shared the story of her sexual assault, which she said happened at a party and was not reported to police.

“I hope students left with more questions than they came with,” Ellis said afterward. “Because for students to start taking interest in actually educating themselves in these topics and becoming empowered with knowledge, that’s how we’re going to end the culture.”

Also in attendance at Wednesday was Alisha Boe, who appears in the Netflix series “13 Reasons Why.”

“We want the survivors in the room today to know that your voice matters, your story is important, and your truth is real,” said Boe, who spoke alongside an executive producer of the show.

A Washington Post-Kaiser Family Foundation poll, conducted in 2015, found that one in five women who attended college in the previous four years said that she had been a victim of sexual assault.

“One in five,” Biden told the crowd Wednesday, referencing statistics on college sexual assault. “Every one of you knows somebody.”

Wednesday’s speech was Biden’s 10th event with “It’s On Us” since the effort launched in 2014 at the White House. The event came a few months after President Trump took office, as many are looking to see how he will handle the issue. During the 2016 campaign Trump drew criticism for a lewd 2005 conversation about women, will handle the issue.

This month, Cosmopolitan published a piece from Biden, in which he wrote that when he introduced the Violence Against Women Act in 1990, the legislation was met with “immediate resistance.”

“Some critics argued domestic violence was a ‘private family matter,’ while others claimed that abused women brought it on themselves,” he wrote. “We’ve come a long way since those days, but make no mistake — we have a long way to go.”