Well Heck Yeah! Being seen is our best safety feature, from any direction! I have looked eye-to-eye while a driver was trying to turn onto a road, and the car came out right in front of me, and he saw me.
Sound travels in all directions. Especially to the side if you are in bumper to bumper traffic traveling at 50MPH, where a huge blind spot exists on a driver's right rear side. Yes, loud pipes were a life saving feature. In a town of 2 million people who are distracted drivers, any feature to get their attention so that I can Share the road, I think is a safety feature.
I actually had to kick doors, going up I-295, heading into DC, because a car would just come over on me.
And I had my horns mounted on the Front, so I hoped that the person presenting a threat to me at the front would have heard it.