I have those musician earplugs... you definitely don't want to pull a helmet on yer' head with those...
...(they have a pokey tube sticking out that will not accept a helmet... yeeouch!)...
Most of the noise you get on a bike,.. is wind...
More specifically... it's the noise of wind bouncing off yer' chest, and blowing upward...
Wear a scarf, if the temperature allows... it will cut wind noise by half...
...