A rotary friend of mine put me onto these and they are by far the best thing I have used.
Simply a custom made plug for your ear, similar to what tv and security people wear.
Basically they plug the bottom of the ear with a thing that looks like a tiny clear plastic mushroom with a long stem which is hollow.
Next they pour in the goo and it sets with the clear tube sticking out.
The comm tube is then connected to an umbilical or in my case plugged.
Perfect fit, reusable, excellent noise suppression what more do you need.
I made the case to my health insurer that I work in a high noise environment and the cost incurred in prevention are far less than NIHL claims. They covered 85% of the cost.