I'll add my data points as well. I've had several bikes, one with a loud aftermarket pipe installed by the previous owner. Of all of them, the one that was noti

I'll add my data points as well. I've had several bikes, one with a loud aftermarket pipe installed by the previous owner. Of all of them, the one that was noticed the most was the larger sport-touring bike with relatively quiet stock mufflers. Visual presence seems far more impactful than increased volume.