I’ve ridden motorcycles regularly since I was 15 and lost several friends in accidents — all them from dumb stuff they were doing. I’ve also really looked into the whole subject over the years.
Almost half of all serious motorcycle-car accidents occur when a car makes a left-hand turn in front of an oncoming motorcycle due to the driver failing to see it.
Most of the rest have to do with stupid riders doing stupid things and inexperienced riders doing things that experienced riders don’t do, like riding anywhere near car’s blind spot or mistakenly assuming that a nearby driver is paying attention.
The other remaining significant cause of serious accidents are the one-off, unpredictable things, like a deer jumping out of nowhere, a sudden tire blow-out, or a head-on collision from an oncoming car suddenly drifting over the center line.
I really doubt sound plays much role in safety except for the inexperienced motorcyclist who casually rides in a car’s blind spot. I suspect safety has much more to do with being visible, being cautious, being extremely aware of one’s surrounding, assuming every driver within site is half asleep, staying clear of other cars, instinctively keeping an exit strategy in mind —just in case a nearby driver does something stupid, and most of all, the experience that comes with practice and a few close calls.
For what it’s worth, my ex and her husband got into a head-on collision a year ago this past August when they somehow drifted over the center line. She was catapulted over the car and came down hard on the pavement about a hundred feet further down the road. Last I heard, she’s still relearning how to walk. I warned her about marrying that idiot she was with, but that’s another story.