The Simpsons go on strike

[Mr. Monday Morning]

Originally Posted by Lamuella if they got people to replace the voices, a large percentage of the audience would call bullshit. It may be easier to replace a voice actor in theory, but if Homer suddenly didn't sound like Homer, people would notice no matter who they got to cover.

Even just sitting around in the pub with friends I've heard people do good enough impersonations of the existing voices that I couldn't tell the difference. I kinda doubt if Fox really wanted to replace them they'd have too much trouble finding people who sound similar enough to the point where an audience wouldn't be able to tell.