Green cars and noise pollution

Eric Leech lays out something that doesn't get written about enough-how electric, hybrid, and fuel cell vehicles might impact noise pollution....

It may be that electric cars are too quiet, in fact, and we will need to find a way to make them noisy enough to be safe.   I would be in favor of that, as part of an overall strategy to reduce unnecessary vehicle noise, especially after-market exhausts (which also must be a hazard to the visually impaired-if a motorcycle with a blaring exhaust is nearby, how do they hear car traffic?)