[Charlie]

Bill, I believe you when you say your 427 sounds great at idle, even with a mild compression ratio. If my theory is right, then you are still getting alot of cylinder pressure because of the long rod-to-stroke ratio parking that piston at TDC longer. If the beer hasn't killed my memory totally, then those kinds of engines like long cam profiles, as you mentioned the FE likes. I will check a few books at home which talk about long-rod engines to see if that is correct.
But lets differentiate between loud engines and powerful pulse engines. My car is loud, it routinely sets off alarms all over this city, so it must be producing some pulse waves. But it is a far cry from pulse producing like a truly powerful engine. Those little riceboy cars are loud, but their sound couldn't set off an alarm if they tried! What Mike made me realize is that the pulse we feel is a pressure wave. It has to be produced by an energy source like a cylinder explosion. The greater the energy under that pressure peak, the greater the pressure pulse we feel in our chest. I believe that is the true cause-effect. All the various engine factors, like cam profiles, compression ratios, breathing efficiency, etc. all effect how strong that pressure peak will be, and ultimately, how powerful the engine is. The difference between my engine and a powerful 427 is the amount of energy in that pressure wave.
The noise we hear is a pressure wave too, with all the various harmonics of the engine and exhaust thrown in too. In the case of the 427, it is a sweet noise. According to you 427 owners, the harmonics all add up to one sweet note, and I believe you.
But I am a bit sceptical that you 427 guys can pick out a 427 from a strong 460 or 429 by sound alone. So I issue a challenge. If you can get a bunch of you together with different engines, then blindfold someone who insists they can tell, and drive the different cars past him so he can pick out the 427 powered cars. Then we will see. Some interesting betting could come of it.
Let me know how it turns out.
One last question. . . does an aluminum block 427 sound the same as an iron block one?
Charlie