which helmet and muffs, Niceviews?
I wear a Ecrin Roc with Peltor muffs (adapter kit). works fine. Last with the visor for 2.5 years. Recently broken.
You might add some extra foam within the muffs if there is room.
A customer of mine makes custom ear plugs that cost about $150, but will last for a very long time. They custom mold them in your ears (more of less). Might be the plugs?
My Stihl dealer just started carrying corded rubber plugs ($3/ pair, with little carry case). Nice to tie on the helmet, cord doesn't seem to interfere too much with the muffs, or at all.
They work really, really good if you put them in all the way, and the most comfortable rubbery plugs I've seen. I can insert them with gloves and they work in the rain, too, unlike foam. Partial insertion allows you to vary the dampening for communication. I think over 30 dB reduction.