I can't always tell from the saddle, but I hear stuff from friends.
Betty has lots of engine mods, but I cannot honestly say I hear a faster idle. In fact, my dyno run sheet shows the curves beginning at somewhere around 600 to 800 RPM.
You could also make the case against that idea. One of the regulars at the Harley shop is a woman who rides a full-dress bike (and I mean 'full') and she also works for Gates, the company that makes Gilmer belts.
While she had absolutely no idea what I had done to Betty, her first comment was, "It sounds 'cammy'..."
Granted, she works around bikes all day long. And being the thick-headed idiot I am, I've watched my mechanic drive my bike and other than the thump of a V-Twin, I don't hear a thing.