But as those norms have changed, the costs of speaking out have dropped.

Younger women in particular are becoming more willing to protest sexual assaults that once might have been deemed too minor to merit reporting. And that, in turn, may be affecting the way older generations of women perceive episodes from their own pasts.

It certainly worked that way for Emily Hoffman, 25, who works in the television industry in New York, and her mother, Amy Plummer.

“I really don’t want to post this,” Ms. Hoffman wrote on Facebook on Oct. 10, a few days after the Trump tape was aired. But she went on to reveal to her 1,326 Facebook friends what for seven years had been one of her most private secrets: that she had been assaulted by a senior male colleague while an 18-year-old intern at a film-promotion company.

He attacked her in a deserted stairwell, Ms. Hoffman announced, kissing her, groping her breasts and genitals, and then forcibly masturbating against her.

“My experience mimicked what Donald Trump described in those tapes,” she said in an interview. “It was very upsetting.”

For Ms. Plummer, who is in her 60s, seeing her daughter’s post was transformative.

“When Emily felt brave enough to put her experiences down was when I specifically started to think about my own experiences,” she said. “And I realized I would not have had the courage she had to say it publicly.”

But she also realized she had things of her own to share. She still felt that some of her experiences were too “explicit” to discuss. But she shared others with her daughter.