Same here. Seems louder with earplugs/mufs in the car. Much better with noise cancelling. BUT remain to be seen if noise cancelling head phones f*ked up my ears. I hope not.
I am experiencing the nastiest spike for about a week. It did start before using them. If they made the spike worse...it's hard to tell. I just want to get through this ( even though i see very little improvement atm) and after that will try them again for just a couple of minutes in the beginning.