There are. Look for "Pass-by Noise". There are standards on how to conduct these tests, and in Europe there are active regulations on maximum emissions already

There are. Look for "Pass-by Noise". There are standards on how to conduct these tests, and in Europe there are active regulations on maximum emissions already in place. It's coming to the US soon too. In the case of the supercars, IIRC the maximum noise is somehow tied to HP or engine displacement so that these guys can get away with more noise. Disclaimer: I work with acoustics simulation software and am currently involved with simulating these kind of tests.