Are you looking for the best hearing protection or the easiest or something that will help hear talking while still blocking out impulse noise?
No, these are good, and I use a pair, but they are not the
best hearing protection.
The best hearing protection are the little foam ones. Properly installed, they offer the greatest noise reduction and a perfect fit every time. Improperly installed they're useless. Look at this:
These are better than custom fit because they give you a fresh fit every time. Custom fit plugs are hard and don't shape themselves to your ear canal. So, if you're hot or cold the shape of your ear canal will change. The custom fit plugs don't change with it. The foam ones will.
Oneounceload is correct about sound getting through via the mastoid bone. Alas, the muff isn't complete coverage of that bone and sound still gets through. Further, muffs by themselves are not that great. The arm of your glasses breaks the seal and reduces the ability to stop noise by as much as half.
Obviously, muffs over plugs is the best. But is it really helping?
Noise Reduction Rating (NRR) is a logarithmic scale. A rating of 3dB will reduce the sound by half. Every 3dB increase in reduction rating will cut the remaining noise in half again. So, just for ease of calculation let's start with a sound that has a number of 100 (no actual relation to noise, this is just for math).
If we have a 3dB NRR, that noise becomes 50
6dB NRR and it's now 25
12dB NRR and it's 12.5
15dB NRR puts it down to 6.25
18dB NRR brings it to 3.125
21dB NRR and we have 1.5625
24dB NRR and now it's .78125
And so on and so on...
The point of this little chart is that once you reach a rating of about 18db NRR, there is very little change in noise reduction as you increase the rating.
Hearing damage happens with long or repeated exposure to sounds at or above 85dB. Short impulse noise, like a gun shot, will damage your hearing at about 120dB. Any hearing protection that brings that noise level down below 80dB will effectively protect your hearing.