X Factor host Dermot O'Leary has praised the impact of Sharon Osbourne on the new series, saying she has brought the best out of the other judges.
He told ITV's Daybreak: "She has brought Louis back into prominence, it's almost like he is an old sheepdog who has just woken up by the fire.
"Gary (Barlow) has a great sense of humour, she brings that out in Gary and her and Nicole are close."
He added that the show had a more "nostaligic feel" this year and that is was much "warmer" than previous series.
X Factor judge Gary Barlow tells a contestant on tonight's show that she has "potential beyond belief" despite being lost for words.
X Factor marks the return of Sharon Osbourne to the judging panel five years after she quit amid rumours of tension with a fellow judge.