The Jonas Brothers are handsome, wholesome, skinny-tie-and-skinnier-jeans-wearing boys from New Jersey who play impossibly catchy and completely inoffensive pop-rock songs. But the sound that has come to define Nick Jonas (15; the cute one), Joe Jonas (nearly 19; the hot one) and Kevin Jonas (20; the other one) has nothing to do with power chords and sweet vocal harmonies: It's the gale-force shrieks that envelop them wherever they go.

"The boys were talking to me the other day and were like, 'Dad. Dad? DAD!' " says Kevin Jonas Sr., the trio's father and co-manager. "Finally I turned around and said, 'Guys, don't be frustrated. If I can't hear, it's your fault.'

"(The girls) are always screaming, and it gets loud; the decibel level is medically intense" — 115 to 120 decibels at a typical Jonas Brothers concert, he says.

Sandblasting is roughly 115 decibels. At 120, you're getting into jet-on-a-runway territory and closing in on the pain threshold.

"You hear it and you think ... some type of monster just ran through the front door," says Joe, a swarthy, rooster-strutting, karate-kicking frontman with male-model hair.

"It's crazy," says Nick, a curly-haired heartthrob who plays guitar, drums and piano and is regarded by most (including Jonas Dad, a former musician and music teacher himself) to be the band's most talented musician.

"So. LOUD!" says Kevin, a rhythm guitarist who has the misfortune — or, perhaps, the great fortune — of being in a band with two guys who tend to overshadow him.

Says Joe: "But we love it. We love hearing our fans go crazy."

In the music business, decibel readings are another metric by which an act can measure success — or at least take a real-time heat check — alongside album sales (1.4 million for 2007's "Jonas Brothers"), touring receipts (robust for the Brothers) and the Billboard charts (a new JoBro single, "Tonight," entered the Hot 100 at No. 8 last week).

A new Jonas Brothers album, "A Little Bit Longer," released last week, was considered a lock to open at No. 1 on the album chart.

They're the new rulers of the boy-band realm, even if they're atypical for a boy band, insofar as they play their own instruments and write their own songs and weren't brought together by some Svengali down in Florida. (So they're like the new Hanson, only with more than one hit.) Not bad for a band that was dropped by Columbia Records early last year, after the first album, "It's About Time," sputtered following its August 2006 release. It sold fewer than 65,000 copies.

The Jonas Brothers caught the ear of Disney executives and were quickly signed to the company's Hollywood Records division, which released the self-titled Jonas album last August. Seemingly overnight, the hydra-headed Disney beast — with its reach into radio, network television, cable and film — helped turn the brothers into multiplatform pop-culture sensations.

They're a band-cum-brand now, with a made-for-TV movie ("Camp Rock"), a scripted series ("J.O.N.A.S.," shooting this fall), a 3-D concert film (out early next year) and a multimillion-dollar touring deal with concert promoter Live Nation.

So when they end their pre-concert prayer circles by shouting, "Living the dream"? Totally not kidding. (And yes, there is a nightly prayer circle; Jonas Dad is a former pastor.)

" 'Living the dream' started as a joke, but now it's true," Kevin Jr. says. "It's really awesome. ... We waited so long to have a tour bus, to have an audience to play in front of — to have anything, really."

The trio began as a solo act, when Nick, who had been performing on Broadway since grade school, started to dabble in Christian music. The deal with Columbia followed — as did Joe and Kevin Jr., who, at the label's behest, formed a secular pop band with Nick.

What JoBro-slagging music critics don't know, the girls understand — though Rolling Stone did just award "A Little Bit Longer" four stars out of five, calling it "as assured as any American rock album released in 2008" and declaring the brothers the messiahs of power pop.

"We were shocked," Nick says about the review. "I thought they had the wrong band."