Will.i.am says fellow The Voice judge Jessie J is like "1,000 volts of excitement".

The Black Eyed Peas star is appearing on the mentoring panel of the British version of the talent show alongside Jessie, Sir Tom Jones and The Script frontman Danny O'Donoghue.

will.i.am is impressed with his co-stars and credits Jessie's ever-present spirit as the perfect pick-me-up during long rehearsal days.

"I love Jessie, she's like 1,000 volts of excitement. She's always making fun of me," he explained in an interview with British magazine Closer.

"I came in wearing these shades and she told me they looked like tea strainers. I was like, Thanks Jessie!'"

will.i.am also had high praise for Welsh singing legend Tom. The 36-year-old rapper-and-singer loved getting advice from the experienced crooner, 71.

"When I get back to the States, I'm going to be bragging to [singer] Cee Lo Green that I got to hang out with Tom Jones. I was so honoured to be around such a legend," he gushed.

"After the auditions, I'd spend loads of time in his hotel room just talking about music and sponging up all those years of experience!"