Nicolas Cage's high-pitched voice he uses in 'G-Force' is the same tone he uses when stressed.

The actor provides the voice for Speckles, a star-nosed computer specialist mole in the forthcoming partially-animated film — about a group of world-saving guinea pigs — and says he didn't need to work very hard to achieve the right tone for his character.

He explained: "The voice was what I call my frustrated, stressed voice. This is a voice that I sometimes resort to if I'm feeling just that. And it's an octave or two higher than my normal voice — this way I don't resort to profanity or yelling.

"And I start talking in that voice, I just immediately start laughing because it's so stupid and so ridiculous that I can't help but not take anything too seriously."

Nicolas was originally approached to take on another role in the film but refused.

He said: "I wasn't going to play a guinea pig. That wasn't going to happen."