I'm glad I saw this, also.
I'm now retired and have no financial interest, but for 15 years, I was a provider of custom ear protection of all kinds.
ALL guns produce hearing damage with every shot, even 22s. Larger cartridges simply produce more damage. You may not notice the blast when hunting, but the damage is still there. Always.
The worst and only dangerous plugs on the market are the"ear valve" plugs, whether they use a valve or a diaphragm. NO such device supposedly powered by sound waves can be faster than sound (that's a duh! if you think about it), so the first, most powerful and most damaging sound wave HAS to get past such a valve/diaphragm BEFORE it closes. Blocking any subsequent but weaker sound waves may give the illusion that they are keeping out some sound, but NOT the damaging part. Result: such plugs are worthless and could be called dangerous.
Solid foam or rubber plugs are fine if they seal and are worn correctly. Note that if there is enough of a foam plug protruding for you to grasp, you are getting, at best, half the plug's rated suppression.
Muffs are not as good as plugs for pure suppression, but do allow you to double up with plugs underneath. The NRR or protection level is NOT additive - meaning a 21 muff and a 25 plug do not give you 46 dB of protection. It's closer to 27 or 28.
THE very best protection is from custom-fit solid plugs because they are made to fit you perfectly and are only comfortable when properly inserted. That leads to wearing them correctly. NRR values run from 28 to 31 which is better than average muffs with foam plugs together.
There is one suitable non-electronic option for hunting: filtered plugs. Filters are completely unlike valves or diaphragms because they have NO moving parts. They use the physics of sound waves to partially self-cancel the sound, and thus CAN protect you from the first big wave. Hocks Inc holds the patent, and the valves can be inserted in flanged rubber plugs or in custom-fit molded plugs.
Electronics are best, but discussing them takes a LOT more space than I can give here. You may go to
www.earinc.com to learn more about any factor I've discussed, plus many more.