Pearl Jam is about to hit the studio for a two-week session in Los Angeles with producer Brendan O'Brien as it continues work on its ninth studio album, which the band plans to self-release in the United States.

After laying down some instrumental beds last summer, additional demos were put to tape in December, and the band's non-singing members formulated another batch of material during a recent trip to Montana.

Frontman Eddie Vedder "put rough vocals on about half the stuff we worked on in December," bassist Jeff Ament tells Billboard.biz. "There's a handful of really great lyrics. Lyrically, that stuff is in the embryonic stage, but there's a handful of lines and a couple of choruses that are just really great. He keeps getting better."

"I saw [guitarist] Mike [McCready] last night and we were both talking about this song and that song," he continues. "One of the songs we decided would go down a whole step and he was asking me about a chord progression."

This will be the first time Pearl Jam has spent significant time recording outside Seattle since 1996's "No Code," some of which was tracked with O'Brien in Chicago and New Orleans between touring. The band is confident the new album will be out in 2009.

"There's certainly been groups of songs that we've recorded very quickly," Ament says. "When we went to Atlanta and New Orleans, we could knock out two, three, four songs in the same amount of days. We did the same thing in Chicago. I'm kind of approaching it with the idea that it'll work out like those sessions did."

Ament says the band is very excited about the return of O'Brien, who hasn't worked on a full Pearl Jam album since 1998's "Yield" but has recently overseen a complete remixing of the band's 1991 debut, "Ten," which will be reissued March 24 on Epic/Legacy.

"He brings a brutally honest approach to what he thinks is working and what isn't, and it really moves things along," he says. We don't get waded down with ideas that maybe aren't even that good. He's one of the few people outside of the band that we trust with our music, and we're really, really looking forward to making this record."

The new album will be the follow-up to Pearl Jam's self-titled 2006 release for J Records, which has sold 704,000 copies in the United States, according to Nielsen SoundScan.