MANCHESTER, N.H. >> Hillary Clinton has been speaking in public for decades. But in recent days, political observers have called her voice “loud, flat, harassing to the ear.” They have said she has a “decidedly grating pitch and punishing tone” and called her “shrill.”

“I think a lot of it with Hillary Clinton has to do with style and delivery, oddly enough,” said Bob Woodward, the veteran Washington Post editor, on MSNBC on Wednesday. “She shouts,” he said, adding that there was “something unrelaxed about the way she is communicating.”

Clinton, who admits she does not have the natural oratory skills of her husband or President Barack Obama, has been tailoring her voice and tone for years. But only in recent days has her speaking style been thrust back into a heated debate about women, sexism and public speaking.

Clinton’s allies berated Woodward for what they viewed as a gender-based critique of her impassioned tone on the campaign trail, pointing out that the stock in trade of her Democratic rival, Sen. Bernie Sanders of Vermont, were his rousing remarks delivered in forceful tones.

“It is 2016 and I cannot believe — cannot believe — we are having this conversation,” said Stephanie Schriock, the president of the group Emily’s List, which works to elect female candidates, in an interview. If Clinton is shouting, “what is Bernie Sanders doing?” she asked.

Even Howard Dean, the former Vermont governor whose 2004 campaign became immortalized by a widely mocked scream, said the criticism of Clinton was sexist. “If she were a male and she were making these kinds of speeches, would people be criticizing her?” Dean said on Fox News.

Clinton can be partly credited for igniting the debate.

After the first Democratic debate in October, when Sanders said “all the shouting in the world” would not fix the country’s problems with gun control, Clinton said, “sometimes when a woman speaks out, some people think it’s shouting.” The campaign later blasted out that line on Facebook and in fundraising emails to excite female voters.

Asked Thursday about Woodward’s comments to MSNBC, Brian Fallon, a spokesman for the Clinton campaign, directed a reporter to the outraged response on social media from many women.

“In today’s America, when a woman is loud it’s ‘shouting,’ when a man yells = enthusiasm. Where am I? Sudan?” Joyce Karam, the Washington bureau chief at the Arab newspaper Al-Hayat, wrote on Twitter.

In general, Fallon said, “that type of criticism gets leveled at women more than it does at men.”

Privately, even Clinton’s friends and supporters say that lately she does seem to be raising her voice more than usual. The tonal shift came in the waning days of the Iowa caucuses, when Clinton displayed a fire-in-the-belly determination on the campaign trail that helped her eke a victory against Sanders.

It is partly a reflection of the changing nature of Clinton’s events. She devoted the early months of her candidacy to speaking to a handful of voters in round-table discussions, and then shifted to larger town-hall-style events where she took questions and nodded intently as voters asked her about issues like Social Security and climate change.

As the voting in Iowa neared, Clinton held larger rallies, drawing hundreds of supporters who chanted and waved her “Fighting for Us” campaign signs. And because Clinton, a former secretary of state and first lady, believes in the importance of 12-point plans, rather than sweeping campaign promises, she often raises her voice when mentioning arcane policy points, which can seem jarring to people unfamiliar with her delivery.

“It’s called an inversion, but I call it a perversion!” is one of Clinton’s favorite lines, referring to the complicated loophole that allows corporations to avoid paying taxes.

“And I’m going to invest in infrastructure!” she often says, lifting her vocal reach as she promises to rebuild roads and bridges and construct high-speed railways.

She grows forceful when emphasizing that the Dodd-Frank financial regulatory legislation includes a provision to break up the big banks, something Sanders has called for through reinstating the 1933 Glass-Steagall Act. “Folks, we already have the authority in Dodd-Frank,” Clinton says, bringing her voice back down to a near whisper.

In settings such as a forum on CNN on Wednesday and in the Democratic debates, Clinton seems comfortable, able to string together paragraphs of complex policy talk off the cuff. But that does not always come through when she speaks to large groups, public speaking experts said.

“There’s a lot of wisdom to the old adage that you almost garner more attention when you whisper,” said Terri Sjodin, a public speaking consultant based in Newport Beach, California. “But there’s an adrenaline that gets high when you’re in a large venue, an auditorium, and a natural tendency to shout or get louder.”

In some ways, the debate over Clinton’s speaking style is a reflection of the larger phenomenon of her candidacy — and that she is the first woman to have a serious shot at becoming a major political party’s presidential nominee.

“Some research suggests women can be competent or likable, but not both,” said Denise Graveline, a former aide in the Clinton administration and the author of “The Eloquent Woman’s Guide to Moderating Panels.” She pointed to the 1984 election, when Geraldine Ferraro, the first female vice-presidential candidate, struggled to find the right tenor.

Ferraro “lacked the credibility of a male candidate, adopted a stronger, more masculine style that may have suited her less,” Graveline said.

The tendency to yell on the campaign stump is not gender specific, but the public is much less accustomed to hearing a woman’s voice in such settings, said Ruth Sherman, a public speaking coach who advises chief executives and celebrities.

“You’ve got a whole generation of new voters who have never heard her in this way before,” Sherman said of Clinton.

But, she added, the former secretary of state, like many public figures male and female, could afford to work on her delivery.

“She tends to substitute volume for expression,” Sherman said.

© 2016 The New York Times Company