The Fox talent contest - showcasing its final four hopefuls - fell three-tenths from last week to an adults 18-49 demo rating of 4.4 and 16.1 million viewers at 8-10pm, which was larger than any other programme on Wednesday.
ABC's The Middle dropped to a season low of 6.65m (1.9) at 8pm, while Suburgatory climbed slightly to 5.98m (2.1) at 8.30pm.
Modern Family rose from last week to claim the second highest demo rating of the night with 4.3 and 10.38m at 9pm. Don't Trust The B---- in Apartment 23 levelled at 7.11m (2.3) at 9.30pm, and Revenge rose to 6.96m (2.2) at 10pm.
CBS's reality series Survivor: One World climbed from last week to 9.71m (2.7) at 8pm, but Criminal Minds dropped to a new season low of 11.5m (2.8) at 9pm.
The season finale of CSI: Crime Scene Investigation was its lowest ever, falling to 10.6m (2.4). However, it was higher than last week's episode.
Betty White's Off Their Rockers climbed to a peak of 5.98m (2.1) at 8-9pm for NBC, while Rock Centre With Brian Williams dropped to 3.64m (0.8) at 9pm.
The newly-renewed Law & Order: SVU slipped to 5.72m (1.7) at 10pm.
The CW's America's Next Top Model was down to 1.05m (0.4) at 9pm.