Ya! Here's Norm with his two cents again.
First, assume you have perfect ear plugs in your ears (correctly inserted!). These plugs let in absolutely no sound!!! You will still hear a lot of noise as the Mastoid bone, the bone in the ear area, passes sound with somewhat over 40 dB attenuation plus a steep frequency response that makes any passed sound sound "dead."
So no plug or ear muff gives "perfect" protection.
Second, if you use foam plugs, and insert them correctly, you will have around 40 dB of protection. That is about as good as it gets! Remember, correct insertion is a VERY important thing, poor insertion can reduce the protection to 20 dB or even worse1 They should be rolled up between the thumb and index finger and inserted quickly into the ear canal and held in place with the pinky finger for a few seconds till they completely expand. Now you have adequate protection from gun shot noise, and you will have a hard time hearing any one talking to you, or range officer commands and in addition their voices will sound muffled.
Third, assuming you insert the plugs correctly, there is absolutely no value in adding a pair of Muffs as they don't add protection, remember the mastoid bone. However, if you are hung up on muffs, you better add plugs as the muffs will NOT give adequate protection unless you are extremely lucky and they fit the exact shape of your head. And, yes, they will probably get in the way of shooting a rifle.
You can argue with me all you like about how good your brand X muffs work, but my education and experience (Both electronic engineering and Audiology) have taught me a severe disdain for anecdotal evidence and value in proper clinical and lab testing. A good hint is to look at the NRR rating of what ever plugs and muffs you are using. The reason the NRR system was developed was due to in-correct inserting or wearing of hearing protection devices. The way that number is derived is by taking the best case protection, say 40 dB for yellow foamies, and subtracting the decrease in effectiveness due to various methods of incorrect insertion/wearing and you get NRR. You may find yellow foamies rated all over the map down to the low 20's. You would be amazed how folks will try wearing them in an environment where they are forced to wear them!
If you like the muffs with a competent compressor amplifier built in to give good hearing for soft sounds and protection for loud sounds, then an appropriate addition would be the one size fits most plugs from Etymotic Research. I think they call them Ety-Plugs now. They have a fixed 20 dB attenuation with excellent frequency response (why they cost $10 or so) and in conjunction with the NRR rating of decent amplified muffs make a good solution.
What do I use? I use Etymotic Research Blast Protectors, EB-15. These cost around $300 a pair on the street and are 3 to 5 times cheaper than their digital competition. These analog devices are much better than digital for two very good and basic reasons. 1. the frequency response is way better with the analog devices ( yes, most digital hearing aids have very poor frequency response as better response costs less battery life) and 2. The digital aids have a time delay built in due to the processing time of the digital signal processor used for an amplifier. This delay can really screw up situational awareness. This is why the military and police like these devices. When the enemy is sneaking up behind you, you would like to be able to "hear" where hi is! And, delay robs you of that ability and the Etymotic devices have been exhaustively clinically tested to prove their efficacy!
Too expensive you say? The last NF scope I bought cost me $1300 plus tax and shipping. Oddly, it does nothing to protect my hearing! Isn't your hearing worth $300-$400?
