Hearing protection when doorless and topless

I don't know about you all, but I find it can get pretty loud when I am driving my Jeep doorless and topless. I commute to work 16 miles one way, with 12 of those miles being on the interstate. 

Getting stuck in slow moving traffic right next to a semi is very loud. A couple of months ago, I bought a pair of DUBS acoustic filters and they really help with the noise. 

They are not really ear plugs where they are meant to eliminate noise. They more lower the decibel level of the noise. They have a plastic body with a small piece of foam inside. 

The round piece that goes into your ear is very soft rubber. I can turn my radio up while driving down the interstate and still hear it, but when a semi gets next to me, it is not loud at all.