The old adage, "It's not what you say, it's how you say it," could prove true this presidential election.

Political observers have emphasized style — from the color of a candidate's tie to the hue of his tan — as a key to winning the hearts and minds of the American public, not to mention the debates. But experts say a candidate's vocal patterns also play a key role in how he's perceived — and can prove even more effective than his actual message.

"The thing that works so well for George Bush is that he speaks in short sound bites. … It can be annoying, but it sticks like a burr in your memory," said Renee Grant-Williams (search), author of "Voice Power: Using Your Voice to Captivate, Persuade and Command Attention." "Kerry will do complete sentences rather than two- or three- word sound bites and I think it's the pace of his delivery that works against him."

This November, in addition to considering the candidates' positions on health care and Iraq, voters can choose between John Kerry's (search) monotone drone and complicated sentence structure and President Bush's (search) quick quips and tee-hee-hee laugh.

Americans got a taste of the candidates' styles during last Thursday's presidential debate, the first of three scheduled face-offs (the next will be Friday night in St. Louis, and the third will be on Oct. 13 in Tempe, Ariz.).

Some Americans may even vote on style over substance. 

"A voter can disregard the content of the monologue and still become attuned to the underlying dedication and enthusiasm a candidate has for his ideas," said Ross Brown, a medical student in Richmond, Va. "I think a quality as seemingly trivial as vocal tone will play a factor in swaying yet undecided voters."

Grant-Williams said Bush's charming "Texas talk" helps him overcome his natural vocal patterns.

"President Bush is a very interesting case because he's very effective in engaging people in spite of the fact that he has a flat, nasal-sounding voice that might typically work against him," she said.

She said she'd encourage the president to breathe throughout his whole body, since his sound often gets caught around his neck and shoulders.

And even Bush's well-known vocabulary gaffes don't seem to hurt his public image, Grant-Williams added. "He's a very unusual case in that he seems to break all the rules of good public speaking and get away with it."

As for Kerry, Grant-Williams said, "he actually has a very warm, resonant voice that one might expect to come from a tall man. And because he tends to speak from his entire, tall body, his voice is very comforting and reassuring, but it's not consistently interesting."

Kerry is known for his droning voice that many say may be a product of speaking in the Senate for two decades.

Grant-Williams' advice for Kerry is to take frequent dramatic pauses and to vary his volume and pitch. He needs to "arrest the listener and make them stop and ponder over what's been said," she advised.

Kerry's long, complicated sentences have been cited by political strategists as something the Massachusetts senator must ditch if he expects to engage voters.

Political adviser Sig Rogich (search) noted that the senator's speechwriters have ratcheted down Kerry's sentences from 15 words to five, "and if he can hold that, it will be an interesting debate process."

The key for both candidates, experts agree, is to sound confident and presidential. Using the entire body to speak helps that effort. Otherwise it can "indicate a person only stands behind what they're saying a little bit," according Grant-Williams.

Body language expert Sonya Hamlin said the way each candidate presents himself can also speak volumes.

In an informal setting, Bush comes across well, she said. He sits with his feet apart and often makes physical contact with whomever he's sitting next to, by putting a hand on a shoulder or an arm.

"He's really quite comfortable in his own skin," Hamlin said.

Kerry, on the other hand, is more stilted, Hamlin said, and his height sometimes works to his disadvantage.

"Something about him that people don't recognize is he's 6-feet-4-inches. When you're 6-feet-4-inches, you don't ease into a chair like you're 5-feet-11-inches and you're brought up on a horse," said Hamlin.

Grant-Williams said both candidates could glean some pointers from Democratic vice presidential candidate John Edwards (search).

"He's actually an excellent speaker, although he uses a slightly higher voice pitch than some of the other candidates. That gives him what I would describe as a boyish, enthusiastic, upbeat quality," she said.

And, Grant-Williams said, there are tricks — such as drawing out consonants over vowels — that can help any public speaker capture an audience's attention.

"The longer the consonant at the front of the word, the more powerful that word or that thought or that idea," said Grant-Williams. "It's like mind control."