Hi,
The foam earplugs that I use have a noise reduction of 32db. When I'm shooting by myself, no need to communicate, I use those. My electronic Howard Leight earmuffs have noise reduction of 23db but voices are easier to hear. I use the earmuffs for class so that I don't misunderstand the instructors, or if I'm shooting with a friend. The Axil and other electronic earbuds are getting popular at my ranges. I'll look into those because they would be less bulky, especially when dealing with long guns.
In general though it seems the passive solutions have higher noise reduction than the active muffs and buds. Only occasionally have I worn both the passive foam earplugs under the active earmuffs. I use whatever works for the situation I'm in.
Thank you for your indulgence,
BassCliff