"You make me wanna scream," she sang before some of the 72,000 audience members jeered.
Simpson, who sang her song "La La," was among a trio of halftime performers Tuesday night in a game that saw Southern California overwhelm Oklahoma 55-19. The camera cut away from her face as the booing began.
The negative vocal reaction came months after Simpson's performance on NBC's "Saturday Night Live," which revealed she used background vocal tracks. Her use of the tracks was later attributed to her bout of acid reflux.
60 Minutes' cameras just happened to be there on the occasion of one of the
Simpson, had performed her hit single "Pieces of Me" without incident during the show's first musical number. When she came back to sing a second time, her band started playing and the first lines of her singing "Pieces of Me" could be heard once again.
Simpson, meanwhile, was holding her microphone at her waist. She looked momentarily confused as the band plowed ahead with the song and the vocal was quickly silenced.
A flustered Simpson
The second season of 20-year-old Simpson's unscripted MTV reality show, "The Ashlee Simpson Show," premieres Jan. 26 and will capture the "SNL" appearance and preparation for her first nationwide tour, which begins Feb. 18 at Los Angeles' Universal Amphitheatre.