Alex,
I'm a former professional drummer,and currently a professional television audio technician(Monday Night Football).
Please,Try this experiment,I have by accident.
1-Put in a cheap set of foam earplugs,make sure you put them in correctly.Roll the foam so it's small.Reach over over your head with your right hand,pull up your left ear,slip the plug in with your left hand till it's snug.This is important,Iv'e seen many guys not put them in incorrectly and not have a good ,snug fit.
2-Drive for about 30 mins to an hour in anything other than stop and go city traffic.
3-Pull over and take the earplugs out and take the return trip.
4-Be amazed at how much noise you expose your ears to.(Noise =Damage)
If you dont take the plugs out and drive right away it's hard to judge the difference.I think we just get used to it and don't notice .I saw a guy today on the street who was jackhammering without any ear protection.he probably just got used to the noise,but that does not mean his ears are not being damaged.
A lot of my musician friends have lost a significant amount of hearing by not using any protection.riding a bike you will be exposed to 100db+ levels just from wind noise not just exhaust:grin:
Ride safe,but always have fun!
Michael