I am a huge fan of wearing 3M E-A-R TaperFit 2 disposable ear plugs and wear them while riding motorcycle, shooting or any kind of noisy work. They fit my smaller ear canals, are comfortable, reusable, and I can find them for under $.12 per pair.
I have been using them for many years with no problems until now. I installed a set of Two Brothers slip on mufflers over the winter and was pleased that they sounded great on the FJR without being overly loud. I rode the bike home from my winter storage garage and forgot to bring along a set of ear plugs. I was mad that I had to listen to the wind but loved hearing the mellow low pitched exhaust. My second ride I remember to pop in my ear plugs and the nice exhaust noise is now ear splittingly loud. WTF?
I have come to find out about a condition called occlusion effect. Occlusion effect is caused by the bones of your head conducting low frequency sound vibrations that are unable to exit the ear because of the ear plug. This actually boosts the low frequency sound levels in the ear canal to an uncomfortable level and spoils the deep mellow sound of the exhaust. I hope to find a solution or the new Two Brothers may have to go.