In one of the third-world countries I know some new singers who copy exactly the voice of a particular famous singer (native to that country too) in their singing.
There are some stand-up comedians who imitate famous singers' singing for fun, and that's not a problem. But there are many new singers who are always copying those singers' voices in their career.
I don't know any new singers who copy famous singers' voices in first-world countries like the US, etc.
So is there a law in, for example, USA to prevent this from happening? Can a famous singer sue anyone for copying their voice? Is Copyright law applicable to voices too?