Jamie Foxx
Singer Jamie Foxx performed the US national anthem before Floyd Mayweather's triumphant fight against Manny PacquiaoYouTube

His vocals were heavily criticised but singer Jamie Foxx insists his shaky performance of the national anthem during fight night was due to technical difficulties.

The 45-year-old was honoured with singing The Star-Spangled Banner before Floyd Mayweather's boxing victory against Manny Pacquiao at the MGM Grand, but he was ridiculed on social media for poor vocals.

Hitting back at the criticism, Foxx told talk show host Ellen DeGeneres: "Now some people were a little upset about how it went down.

"But here's the thing first of all, anytime a black person sings the national anthem you know we gotta [proceeds to sing soulfully]."

Explaining the issue with his earpiece, the Ray actor continued: "But what did happen in the ring [is] my ears came out. My inner ears.

"My inner ears came out and I'm singing with an organ so I can't hear what the organ is doing with the big crowd."

He added: "So some of it was a little off, but in the arena it killed. The telecast was a little off. But you know we still love America!"

During another interview with Access Hollywood, the Oscar-winner told critics to "calm down" before claiming: "I think a little bit was just people wanted to have something to talk about. But everything's cool."

Foxx then joked that his rendition of the national anthem will feature on his new album, quipping: "The National Anthem will be on my album. And I'm gonna do whatever the hell I want to."

In the midst of the controversy, footage has emerged of actor Jake Gyllenhaal and Hollywood movie director Antoine Fuqua appearing to laugh hysterically during Foxx's performance.

Comic actor Marlon Wayans has also responded to the furore and defended the Annie actor, telling TMZ: "I know how brilliant the genius Jamie Foxx is. I used to work with him and heard him sing like an angel."

After admitting Foxx's performance was not as good as Whitney Houston's iconic version or as bad as Roseanne Barr's, Wayans said: "But here's the thing - he's out in Vegas.

"You're hanging with Floyd, you're hanging with Puff [P Diddy], you're drinking [alcohol], you're partying your a*s off, so it's kind of hard to hit those notes when you've got all that [alcohol] in your system."

He added jokingly: "It sounded like his voice was a little drunk. Everybody has an off night and that was [one of his]. He'll do it better next time."

Watch Jamie Foxx's interview with Ellen DeGeneres below: