What's the law in Connecticut regarding helmets and 3 wheelers?
In Vermont, by the book, the helmet is required as the car is classed as a motorcycle. I've been given a written warning in VT and have found that NY and MA are hard nosed about it. NH doesn't give a damn. Something about freedom but I honestly think the state needs organ donors...
Back to topic, a helmet helps with the noise. I also carry 3M ear plugs. The end of the tail pipe is about 2-1/2 feet from the left ear! I've been wearing a helmet more and more as it's a great way to keep the noggin warm at the beginning and end of riding season. Also as a defense measure, one June bug in the middle of the forehead at speed will surely smart!
What's your mileage? Who cares. Is it practical? See #1. What happens when it rains? You get wet.