I know when I first started out I had to look around a bit to decide what was important in hearing protection and what to look for so I thought I'd compile some information here in hopes that it might help others. Measuring Sound: Loudness is measured in decibels (dB). This is logarithmic measurement, every increase of 3dB doubles the sounds intensity. Generally however it will take a 10dB increase for us to perceive the volume as twice as loud. Lets look at some common sound levels: breathing at 3m - 10dB whispering - 30dB office or restaurant - 60dB expose past this point can cause hearing damage - 85dB lawn mower - 90dB 15 minutes of exposure can cause hearing loss - 100dB 1 minute of exposure can cause hearing loss - 110dB accelerating motorcycle at 5m - 110dB rock concert - 120dB threshold of pain - 130dB jet engine at 30m - 150dB Gunshots and hearing: 1000 sound impulses max a day at this level per OSHA - 130dB .22lr rifle 134dB 100 sound impulses max a day at this level per OSHA - 140dB .223, 55GR. Commercial load 18" barrel 155.5dB .243 in 22" barrel 155.9dB .30-30 in 20" barrel 156.0dB. 7mm Magnum in 20" barrel 157.5dB. .308 in 24" barrel 156.2dB. .30-06 in 24" barrel 158.5dB. In 18" barrel 163.2dB. .375 18" barrel with muzzle brake 170 dB. .410 Bore 28" barrel 150dB. 26" barrel 150.25dB. 18" barrel 156.30dB. 20 Gauge 28" barrel 152.50dB. 22" barrel 154.75dB. 12 Gauge 28" barrel 151.50dB. 26" barrel 156.10dB. 18" barrel 161.50dB. .25 ACP 155.0 dB. .32 LONG 152.4 dB. .32 ACP 153.5 dB. .380 157.7 dB. 9mm 159.8 dB. .38 S&W 153.5 dB. .38 Spl 156.3 dB. .357 Magnum 164.3 dB. .41 Magnum 163.2 dB. .44 Spl 155.9 dB. .45 ACP 157.0 dB. .45 COLT 154.7 dB. The first thing anyone has to notice is that firing any gun, even a .22lr in a rifle without hearing protection is loud enough to cause hearing damage. Protection: In general ear plugs are better at blocking low frequency noise, ear muffs are more effective against high frequency. Ear protection in the US will have a NRR number assigned to it, this is the dB drop it should give you. For example if you're around 60dB of noise and wearing NRR 30 plugs, your ear should be getting 30dB of noise. Doubling Up: Some shooters chose to double up on their hearing protection. Personally I shoot indoors and find this to be especially wise. Sadly however you can't just add the NRR values of your hearing protection to get the total reduction value. The OSHA guideline is that you get to add 5dB of NRR to the highest rated protection device with the addition of a second one. For example wearing plugs rated 33nrr and muffs rated 30nrr give a total nrr of 38dB. Some speculate the gains are greater and that estimate is conservative. On the surface this doesn't seem like much, but when you consider that 3dB is a doubling of sound level, it is indeed worth quite a bit. For example lets say you're indoors shooting a 9mm with 25dB muffs on. Your 160dB sound has been attentuated to 135dB in your ear. You're at a maximum of 500 impulses at at that volume before hearing damage according to OSHA. If there are others shooting at the range that day and you intended to go through a hundred or more rounds yourself, its quite easy to see how you could exceed the allowed exposure levels that day. Things get even worse if someone on the range with you is shooting magnum rounds. However if you had the 38dB of protection discussed earlier from doubling up you would be exposed to 122dB of sound from each of your shots and would be safe well over a thousand shots. If you have comfort problems with ear plugs an audiologist should be able to mold a custom fit set of ear plugs for your ears. It may well be worth it for the frequent shooter. Protests: Now some of you will say you've been shooting for years with little to no protection and haven't noticed a problem. To that I would point out that hearing loss is gradual and often starts with higher frequencies first. You could very well have hearing loss that you just don't realize yet. Some people will get tinnitus (rining in the ears) and it will be quite noticeable. An exam might be recommended if you question it. The final thing to keep in mind is when you get to the truly damaging sound levels, is that the damage done to your hearing is permanent and cumulative. It will get worse every time you get to those damaging levels again. Reference material: http://www.answers.com/decibel&r=67 http://www.mckinley.uiuc.edu/handouts/noise_ears_hearing/noise_ears_hearing.html http://www.american-hearing.org/name/noise_induced.html http://www.pro-am.com/Catalog/Product_Advice/Hearing_Protection/willson1.asp http://www.freehearingtest.com/hia_gunfirenoise.shtml http://www.thehighroad.org/showthread.php?t=183414 I hope this can be a decent reference to those who are getting started or wanting to see if their hearing protection is effective enough. I just got in some replacement protection today that I'd like to point as being quite effective for me: First is a package of Leightning L3 muffs with a NRR of 30dB ($18.46) and second is 100 pairs of Howard Leight plugs with a nrr of 33dB ($24.01). Both seem comfortable and have some of the highest nrr values you can find. I ordered them from http://www.tradingpostsupply.com and the shipping was fast. I previously ordered some leightning muffs from a different seller and had nothing but problems from the other seller (consider that fair warning if you use froogle or ebay to try to find a cheaper price). Their item number for the plugs is HLR33133 and HLR03318 for the muffs if anyone wants to try them. My only complaint is you can forget about using the muffs with a long gun.