(Cycling) at the bottom of a 3mile climb, say to mate.. "There's a Ducati coming" Sure enough two of them appeared, I could tell roughly where they were due to gear changes and local knowledge. On an average sunday night lying in bed I can hear bikes and cars travelling in all directions, this notion of exhaust noise being behind you and being pointless is absurd. I don't know if loud pipes truly do save lives, in much the same way as any internet helmet debate is inconclusive - I'll have a non-standard exhaust over a quiet OEM one any day of the week, and I'll also wear a helmet as a cyclist.
A driver inside a soundproof glass box with the windows up and radio on is unlikely to be hearing much.. That's the crux