At a guess, I'd say that it has more to do with header/manifold configuration
I don't think that is the case.
For example, take a drag racer (A-modified, AA fuel, funny car, your choice) where the exhaust system consists of eight equal-length straight pipes coming right out of the cylinder head. The sound is unmistakably V-8. I have heard other engine configurations with similar exhaust setups, and they are readily identifiable by their sound.
AcuraSquirrel... where are you when we need you?
tanstaafl.