Neil Diamond, somewhat disconcertingly, speaks the same way he sings. The same baritone voice. The same rich timbre. The same melancholy inflection. The cadence with which he once sang, “Where it began / I can’t begin to knowin’ / But then I know it’s growin’ strong” is the same one with which he now says, “Falling in love is such a wonderful feeling to experience at this point in my life.” Such is the effect that, were he to bust out in song (“Good times never seemed so good!”), you would not be the least bit surprised, but would do the only acceptable thing — which, of course, would be to answer: “So good! So good! So good!”

Alas, it never happens. But that voice, so familiar and warm as it fills the empty spaces of a salon in a Midtown Manhattan hotel, sounds as though it should be drenched in strings, his declarations punctuated by a majestic, descending horn figure (“Bah bah bah!”).

“Exhilaration,” Diamond says, “is the operable word this year.” (“Bah bah bah!”)

And when Neil Diamond speaks of falling in love, and speaks of exhilaration, he, of all people, can be trusted. No one in pop music has ever done emotion like he has, from the dark loneliness of “Solitary Man” to the spiritual yearning of “Holly Holy” to the existential rage of “I Am . . . I Said” to — yes — the sheer exhilaration of “Sweet Caroline.” (There’s your cue, folks: “Bah bah bah!”)

And now, 70 years into an extraordinary life and 45 years into a career as a hit-maker, Diamond is experiencing the kind of run that younger men can only dream of, with his love life in autumnal bloom — he is preparing to get married for the third time, this time to his 41-year-old manager, Katie McNeil — and his career in a period of critical reevaluation that amounts, in Diamond’s own description, to “validation.”

When Diamond receives the Kennedy Center Honors this week, in recognition of a lifetime of contributions to American culture, it will be the third time this year that he has been bestowed with this sort of cultural immortality, following his induction into the Rock and Roll Hall of Fame in March and his acceptance of the inaugural Billboard Icon Award in May.

“Fortunately . . . the people in the know are calling me positive things instead of the negative things,” Diamond says. He is outfitted in minimalist black: black sweater, black jeans, black slip-on shoes, black wristwatch. The plain black baseball cap and black leather jacket he wore into the room have been removed and placed on a table.

“I don’t see myself as an icon at all,” he says. “I see myself still as a struggling artist trying to create music. And that’s what I do every day. And it’s the same kind of struggle I’ve had since I began — feeling inadequate to the task, and sometimes achieving something that uplifts my own spirits and that goes on to uplift the spirits of others. It’s my labor.”

If you detect a dark undercurrent in Diamond’s words, a barely concealed questioning of his own self-worth, you would not be overreaching or incorrect. Even in the midst of this career-validating run of honors, he has maintained a distance from the sentiment involved. And something beyond mere modesty is at work here.

This was displayed most vividly nine months ago at the Rock and Roll Hall of Fame induction. It was an honor that, notably, arrived for Diamond a full 20 years after he first became eligible. (Paul Simon, who introduced Diamond, posed the obvious question, “What took so long?” — then, to howls of laughter, offered up his own theory: “Six words: You. Don’t. Bring. Me. Flowers. Anymore.”)

Jet-lagged and loopy (he had interrupted a tour of Australia and flown halfway around the world for the ceremony), and working without notes, Diamond unleashed a gloriously meandering, profane, off-the-cuff speech that had guests unsure whether to laugh or cringe.

“I’ll bet every table here has at least one person that I’ve worked with,” he said at one point, staring at the luminaries seated up front. “[But] would they admit it?” At the end of the speech, he blurted, “And I’m flying back tomorrow to Sydney [expletive] Australia — because they love me there. And I’m going to keep coming until they stop loving me.”

Asked now about that speech, Diamond, who credits his regular visits to a therapist since the early 1970s for his blossoming as a songwriter and an artist, does not hide from the deep-seated emotions it revealed.

“My comments . . . were real,” he says. “There was a certain amount of resentfulness.” Asked where that resentment comes from, he says, “I don’t know. I don’t understand it. Maybe it comes from 40 years of being sidelined by the powers that be.”

It’s true that for much of his career, Diamond was considered (at least) one step behind the times. As a Brooklyn kid who dropped out of his pre-med studies at New York University to write songs for the Brill Building machine, he was crafting hits for the Monkees (“I’m a Believer,” among others) at a time when they were being mocked as saccharine pretenders to the Beatles’ throne.

He arrived as a solo artist in the late ’60s, at a time when record companies were infatuated with British bands. As rock music grew heavier in the ’70s, Diamond’s became softer, and even his epic live shows were easily mocked — the “Jewish Elvis,” he was dubbed — for his emotive earnestness and his wardrobe of gaudy, sequined shirts.

“From the first guitar riff of this profit-taking double live showcase,” the influential critic Robert Christgau wrote of “Hot August Night,” Diamond’s landmark 1972 live album, “it’s obvious that the man is some sort of genius rock entertainer, but for the most part the great entertainer is striving for bad art and not even achieving it.”

“I’ve been kind of battling that throughout my career,” Diamond says now. “And I think it probably reinforced my feelings about — focus on the work, and not on all the chatter going on around the business and the media.”

For decades, Diamond contented himself with selling gazillions of records, filling arenas worldwide (he was the highest-grossing live act in pop music as recently as the 1990s) and owning the adult-contemporary charts (37 top-10 singles since 1969, according to Billboard, second only to Elton John).

He became, in effect, the nation’s guilty pleasure, his commercial success attesting to the universal appeal of his songwriting and the energy of his live shows, even if it was becoming increasingly unhip to acknowledge liking him.

“I saw it happen every night — somebody being dragged [to a show], either the husband or the boyfriend, who didn’t really want to be there, but who came away a lifelong devotee of Neil’s,” said Richard Bennett, Diamond’s lead guitarist from 1970 to ’87, and a songwriter who is credited with co-writing “Forever in Blue Jeans,” among other Diamond tunes.

“It’s a combination of his brilliance as a showman and a songwriter,” Bennett said. “You actually forget how many great songs he has until you go to one of his shows, and it’s just one after the other — two hours of all these hits. ‘Oh, man. I forgot about that one!’ It’s like the soundtrack of your life.”

One of Diamond’s chief defenses against those who would mock him has been a well-honed ability to laugh at himself. When Will Ferrell took to parodying him on “Saturday Night Live” in 2002, Diamond showed up in a cameo alongside Ferrell in the season finale. He once surprised one of the several “Neil Diamond tribute” acts, the L.A.-based Super Diamond, by sitting in on “I Am . . . I Said” — then joking, “I guess it should have been ‘We Are . . . We Said.’ ” In the forgettable 2001 teenage comedy “Saving Silverman,” about a floundering Diamond tribute band, Diamond makes a lengthy cameo and leads the cast in a resounding “Holly Holy” at the end.

But anyone who has ever known the wretched task of trying to craft a perfect three-minute pop song could understand the genius of Diamond, who has done that as well as anyone in the past half a century. And one of those people who understood was acclaimed producer Rick Rubin, who made some of the best records ever released by the Red Hot Chili Peppers and the Beastie Boys, among others, and who, in the 1990s and 2000s, produced the critically lauded “American Recordings” series for Johnny Cash, which revived Cash’s career.

“I love so many of his songs, and always felt he stood alone as an artist,” Rubin said of Diamond in an e-mail interview. “He has always done what he wanted and followed his inner voice, so he never fit easily into any genres or categories.”

Rubin approached Diamond about working together, and after agreeing, Diamond holed up for nearly a year and a half, he says, “writing and writing and writing and writing.”

The two resulting albums, 12 Songs” in 2005 and “Home Before Dark” in 2008, are both stripped-down and spare, much like Rubin’s Cash albums, in a way that emphasizes Diamond’s songwriting and voice. Despite Diamond’s initial objections, Rubin insisted that he play guitar and sing simultaneously in the studio, which gives the records a coffeehouse intimacy that stands in stark contrast to the bombast and syrup of his mid-career output.

“They’re two good albums,” Diamond says. “They have some of the best songs I have written.”

In the past, although he always laid himself bare in his songwriting, Diamond would cover himself back up with layers of orchestration in production. Here, there was nowhere to hide, not even when, in “Act Like a Man” from the “Home Before Dark” album, he pointedly questions his self-worth: “Songmaker / You heartbreaker,” he sings. “You know you’re just a worthless daydreamer.”

So began this new phase of Neil Diamond’s career, one in which the commercial success would be paired for the first time with widespread critical acceptance. The records garnered some of the most glowing reviews of Diamond’s career, and “Home Before Dark” became the first top-10 album of his career. It wasn’t as if he were descending into the Vegas-showroom or state-fair phase of his career by the time Rubin came calling, but before “12 Songs” Diamond hadn’t had so much as a top-10 album of new material since “Heartlight” in 1982.

Perhaps the Rock and Roll Hall of Fame nominating committee would have come around to him eventually anyway. But it certainly appears that Rubin’s interest in Diamond set in motion a critical reevaluation of his oeuvre that resulted in this year’s series of honors, and a certain (dare we say it?) hipness that had always eluded him. He might still be your mother’s favorite singer, but these days he might also be your daughter’s favorite musical icon. (He did appear as a mentor on “American Idol” in 2008, after all.)

Diamond was once asked to dance by Princess Diana. His songs have been covered by Elvis and Sinatra. He has sung duets with Streisand. He has known love and loss. He has sold 120 million records. But until these past few years, he had not known what it felt like to be embraced both by the folks who buy the CDs and tickets and the “powers that be,” as he calls them.

Such acceptance, Diamond says, “wasn’t important to me until I got it — I finally got it, and I enjoyed it.”

Outside the hotel, a rainy New York afternoon is expiring, and the evening spreads itself open for the septuagenarian singer and his soon-to-be bride. Diamond announced their engagement in September on Twitter. (“I’d like you to meet Katie,” he tweeted, along with a picture. “I’m lovestruck.”) Diamond is quick to point out that his 93-year-old mother, Rose, who lives near him in Los Angeles, “loves my fiancée.”

He puts back on the black leather jacket and the black cap. He is ready to show Katie around New York, the place where it all started, his home town. L.A.’s fine, you know, but it ain’t home.

Here, at the coda, the strings ought to be kicking in, building to a fortissimo, but there is no accompaniment as Diamond, in that robust baritone, bids farewell and reaches for the door. In love again, and in ascendance, he doesn’t need any embellishment anymore.

See the rest of this year’s Kennedy Center Honorees:

Meryl Streep | photos

Yo-Yo Ma | photos

Sonny Rollins | photos

Barbara Cook | photos