At one time, I used only the Clark protectors, until I found out how little protection they provided alone. I then added ear plugs to the mix, and I continue to wear both today.
I tried various brands - Clark, Silencio, Peltor, Remington, et al., but the best I've found come down to the following -
- Peltor Tactical Pro
- Pro Ears Gold
Both are expensive, but they provide the best protection among all the active protectors.
I also wear custom-molded plugs with them. In fact, I just had two pairs made today at our club. My older custom-made plugs are still good, but they have a limited life to them, also.
Here's a link to NIOSHA. They have an extensive amount of data, and they've tested most every brand of hearing protection available. It's one of the few civilian initiatives the federal government has done well.
NIOSH Topic: Noise and Hearing Loss Prevention | CDC/NIOSH
I sent them an email, and one of their engineers called me and spent over an hour on the phone, and very patiently answered my questions, providing me with a wealth of information.