The British singer-turned-fashion-designer was determined to impress during her first stint as a judge on the US TV talent show, so called on some experts to give her advice.
A source said: "Victoria knows she has a very thick British accent and is sometimes misunderstood in America. She wanted to come across the best she could on 'American Idol', so she took some private lessons on how to properly pronounce words and how to make appropriate facial expressions.
"Victoria is famous for her pout but she herself admitted she wanted to shed that pout for the show to come across more human."
As well as elocution tips, the 35-year-old star also underwent drama lessons ahead of her appearance.
The former Spice Girls singer admitted her three sons with soccer star husband David - Brooklyn, 10, Romeo, six, and four-year-old Cruz - persuaded her to take part in the show as they love it so much.
She added before filming her part: "I'm going to try hard to pout and not shatter the illusion that I'm a moody cow, but I don't know if I can. I'm just so happy."