Sometime an individual comes up with a subject so obvious.... I think you have something here.....Once upon a time riding my GL1000 ( quiet by any measure) I counted 131 deer on the side of the road one night , all within a 50-mile stretch of Hwy.... they looked as I got close but none of them "bolted".... conversly , when I had my Kawasaki Vulcan with "loud pipes saves lives" there were several that descided to say "howdy" to my new ride in the middle of the road !!!....... BUT I must say...cagers have told me ( sometimes with a one-finger salute) they "heard" me...... did this keep them from pulling into my lane ??? This is a great question to ponder that you have posed my Canadian cousin.