There are many ways to protect yourself as you head out on the road as a motorcyclist, such as wearing a helmet and light colored clothing, and being self aware of what is going on around you at all times.
But some feel as if having a loud exhaust on the back of a motorcycle makes other drivers notice your existence. The pipes on the back of some of the bikes are so loud that you can hear the sound revving out of the exhaust through your walls of a business or your own house.
However, loud tailpipes may not be as effective as you think. According to a report back in 1981 on the cause of motorcycle accidents, 64.9% of accidents are caused by the actions of the driver. In most cases, the driver operating the motor-vehicle would fail to see the motorcycle in the left lane due to a blind spot. A report on motorcycle accidents within the past 10 years backs this conclusion up.
And think about this: There are a lot of distractions that happen inside the car itself. Speakers blaring, kids crying and or unfortunately somebody could be on their cell phone, looking straight ahead while forgetting to look twice before switching lanes.
So if you add a loud muffler on the back of your motorcycle for the sound, go for it. However, it can't guarantee drivers around you will notice your presence out on the road.