There are several explanations for why Ms. Gillibrand’s statewide approval ratings have spent a year mired in the mid-20s, despite her superior title and elevated profile: Her appointment process was publicly bungled; her stance on issues like guns and gay rights evolved in disarmingly short order; and, since she’s never had to run a statewide campaign, many voters still don’t know who she is, or, for that matter, what she’s doing down in Washington.

But the junior senator may also be battling something more fundamental: her voice.

“Kirsten Gillibrand has what I would call a non-regional American young female’s accent,” wrote Dr. Bert Vaux, a sociolinguistics scholar at the University of Cambridge, who was asked by The Observer to analyze Ms. Gillibrand’s public speaking. “Though I lack the phonetic expertise to put my finger on what exactly is involved in this, her voice quality is of the sort that is typically associated with pre-workforce-age white American females. Judging by the case of this woman, this speech pattern has now extended into higher age ranges.”

Though Dr. Vaux stressed we should all avoid our “pre-programmed” tendency to form biases based solely on someone’s speech, he noted that Ms. Gillibrand often employs a “rising intonation pattern at the end of declarative clauses that lay people tend to associate with teenage girls,” a tendency that gives way to a “classic trigger of linguistic profiling.”

Translation: She sounds more like the cheerleader than the class president.

Ms. Gillibrand offered one concrete example of this amid a scrum of reporters in Harlem earlier this week. “Martha’s gonna wiin!” she squeaked, referring to Martha Coakley, the Democrats’ embattled Senate candidate in Massachusetts. “Martha’s gonna wiiiin!” she said, her voice rising even higher. “Just be positive!”

“In general, she speaks in a much less formal register than one expects from a senator,” Dr. Vaux wrote.

What exactly one expects from a senator has become a subject of growing debate, as Ms. Gillibrand increasingly tries to beat back a potential primary challenger, former congressman Harold Ford Jr.—a smooth-talking scion of Tennessee’s back-slapping political establishment, whose chief qualification seems to be that he presents better than she does.

 A Poor Contrast

Take, for example, a joint appearance by the senator and her would-be challenger on Jan. 18 at Al Sharpton’s Martin Luther King Jr. celebration in East Harlem.

Mr. Ford was in his element. Speaking without notes, he leaned on the lectern and spun stories, effortlessly, about the years he spent growing up around his grandmother’s house in Memphis. (He made sure to include the anecdote that spawned his forthcoming book—More Davids Than Goliaths, slated for publication one week before New York’s primary.) His cadences were relaxed and familiar. When he delivered his laugh lines, the audience laughed. When Mr. Ford began a Bible verse, the audience piped up to help him finish it.

“I felt like he knew how the audience would respond,” said Dina Mathis, a 43-year-old from Co-op City who was in the audience.

“He’s great,” one reporter gushed to another.

Ms. Gillibrand’s delivery was somewhat less inspiring.

“At this time of immense hope and possibility, that is best symbolized with Barack Obama as our president, there is still inequity, injustice and inaction that persist,” she said.

The speech received occasional bursts of polite applause.

“It was a well-written speech, but unfortunately, she read it,” said Bronx Assemblyman Michael Benjamin. “It didn’t come from her emotions. Be passionate. I like what she said, but it didn’t come across that way because she was reading it.”

With grim, almost systematic regularity since her appointment as senator, Ms. Gillibrand has underwhelmed audiences at precisely the times at which the most eyes were on her. At her initial press conference on Jan. 23, standing beside Al D’Amato, she named a long list of relatives and mentors, and touched on a hodgepodge of policy issues, without any discernible narrative arc or even basic structure. In the process, she missed a congratulatory call from the president.

And then on July 13, when she was given five minutes to introduce Supreme Court nominee, and fellow New Yorker, Sonia Sotomayor—a national coming-out party engineered in part by Ms. Gillibrand’s mentor, Senator Chuck Schumer—Ms. Gillibrand delivered a deliberate set of remarks that came painfully close to sounding like a biographical report presented to the class. As she stretched past the six-minute mark, the Senate Judiciary chairman, Patrick Leahy, had heard enough.

“Senator, we’re going to have to put your full statement in the record so that Judge Sotomayor can be heard,” Mr. Leahy said.

“May I conclude my remarks?” Ms. Gillibrand asked with a smile

“If it can be done in the next few seconds, Senator.”

“Yep, one minute,” she said.

He grumbled. She skipped to her last line.

(“A well-known phenomenon in the world of language and gender studies is that females get interrupted more than males,” Dr. Vaux told The Observer. “Leahy’s interruption of Gillibrand’s speech was a classic example of this.”)

“It is one of the first big opportunities she had to be in front of a big audience and really distinguish herself and appear senatorial, and she just didn’t,” said Jennifer Duffy, who covers Senate races for the Cook Political Report.

“It could be a combination of youth and voice. I think youth is a harder thing for women,” Ms. Duffy said, citing the frequent comparisons of Ms. Gillibrand to Tracy Flick—the ambitious (and blond) young politician from the movie Election—a comparison for which there’s no real male equivalent.

Political science professor Larry Sabato of the University of Virginia said that even the voice, and overall impression of Flickiness, didn’t entirely explain why Ms. Gillibrand has been just so forgettable.

“There are a lot of women in the Senate who are very memorable,” said Mr. Sabato, who added that he literally could not remember the last time he saw Ms. Gillibrand give a floor speech, even though he knew she had given plenty.

“She just kind of blends into the background,” he said.

In the Shadow of Schumer

In early December, Ms. Gillibrand sat in Fox’s New York studio for a soft, Monday morning interview with Greg Kelly of Good Day NY. “One thing I have noticed: Senator Schumer, your colleague, he’s out there just about every Sunday on some issue,” Mr. Kelly said. “Yesterday it was ATM fees, last week it was—T-shirts in Asia?—I don’t know, some issue, but he’s always out there. We haven’t seen that much of you. Is that just deference to the senior senator, or how does that work?”

Ms. Gillibrand explained she had been out traveling the state, and promised that everyone would be seeing more of her. Of course, she did not point out to Mr. Kelly that she had, in fact, appeared on Good Day NY several times since her appointment.

Over time, it seems that Ms. Gillibrand’s advisers have worked so hard to blend her into her new office, controlling her public appearances and restricting the opportunities for off-the-cuff answers that might go astray, that she now almost leaves no trace.

“The purpose here was to create the stealth senator,” posited consultant Hank Sheinkopf. “Make no trouble. Have no primary. Have no general election and just keep moving. So if you don’t take any controversial positions, nobody pays any attention to you. And if you don’t spend a lot of time in New York City, where the media is, then nobody else will pay much attention to you. You just kind of float along.”

The strategy appeared to be working, until two weeks ago. “If Ford jumps in, the strategy of ‘make no waves and make no trouble’ backfires, because what occurs here is, she hasn’t used her time well enough,” Mr. Sheinkopf said.

The consensus among consultants these days is that Ms. Gillibrand’s carefully calibrated attempt to carve out a legislative and advocacy niche for herself as Senator Working Mom—with a focus on issues like healthy school lunches and safe baby products—just isn’t substantive or ambitious enough for the occupant of a seat once held by luminaries like Bobby Kennedy, Daniel Patrick Moynihan and Hillary Clinton.

“Clearly, her handlers want to diminish the number of mistakes she can have,” said political veteran George Arzt. “But people want to see her out there. People want to see their representatives out there. People want to touch and feel them. Harold Ford is out there. He makes a lot of mistakes, but Harold Ford is out there.”

And now, it would seem, Ms. Gillibrand has to be out there, too.

The good news: Maybe presentation isn’t everything.

Whether she arrived there with unseemly haste, and for reasons that were far more pragmatic than heartfelt, she is, as her supporters point out, “right” on the issues in question.

“If we did the Pepsi taste test, and we presented the two sets of positions that the senator and her potential opponent have—without identifying whose they were—there’s no question in my mind that Democrats in New York would choose Senator Gillibrand,” said Retail, Wholesale and Department Store Union head Stuart Appelbaum.

Also, maybe more to the point, New Yorkers have a proven willingness to elect senators based on attributes other than their ability to make speeches.

“For Christ’s sake, have you ever seen Schumer speak? His graduation address every time he comes here is the same speech. The guy is not an orator. He’s not John Kennedy,” said SUNY New Paltz professor Gerald Benjamin. “Interpersonally, she’s very good. And she’ll be coached, and she’ll be trained.”

rpillifant@observer.com

Additional reporting by Azi Paybarah and William Akers