Wednesday night's two-hour show, which introduced new judge Kara DioGuardi and was noticeably less intent on humiliating the talent-deficient, was the most-watched prime-time program of the TV season so far, according to Nielsen Media Research.
Yet it was down 10 percent from the 33.4 million who watched the 2008 debut. The 37.4 million who watched the 2007 debut represents the series' high point for opening nights.
The decline is consistent with what is happening on broadcast TV this season, said Peter Liguori, Fox entertainment chairman. A hangover from last year's writers' strike and the increased use of digital video recorders means that year-to-year growth in live viewing is the exception rather than the rule.
"We're unsatisfied because within the `Idol' universe, you never want to see year-to-year erosion, ever," Liguori said. "With all that being said, I think we're optimistic about the show's performance from this point forward."
Of the 20 most popular prime-time programs at this time last year that returned for another season, 14 have lost viewership. The six shows that have increased their audience this year, such as "NCIS" and "Two and a Half Men," are all on CBS.
Before "Idol," the most-watched prime-time entertainment show of the season had been the season debut of CBS' "CSI: Crime Scene Investigation," seen by 23.5 million viewers on Oct. 9. Until Tuesday night, the most people gathered around the TV for a single show was the 27.8 million who watched the Indianapolis-San Diego NFL playoff on Jan. 3.
"American Idol" was praised by one of Fox's rivals, CBS Entertainment President Nina Tassler, on Wednesday when she cited it as a reason advertisers stick with broadcast networks.
"You don't find these kinds of numbers on cable or any other medium," Tassler told a meeting of the Television Critics Association. "Network television still works when advertisers and audiences respond to creative, high-quality content."
Liguori said the effort to be more "aspirational," or focus on the personal stories and dreams of would-be idols, should help the show appeal to more female viewers in its eighth season.
Fox is also cutting its run of tryout sessions from four weeks to three to spend more time in Hollywood, he said.
"Our anticipation is there should be greater strength from this point forward," he said.
Associated Press Television Writer Lynn Elber contributed to this report.
By Davis Bauder