As a musician, music fan and audio engineer, I have spent a lot of time considering the long-term damage that can come from exposure to high sound pressure levels (SPL). Here are some guidelines that you can use to keep yourself safe, and some personal suggestions.
(The following assumes 10 hours of recovery time <70dBA. If this exposure occurs every day, subtract 5dB. For musicians: you can also assume 3-9dB quieter onstage or in a DJ booth.)
83dBA=safe for 16 hours
85dBA=safe for 8 hours
88dBA=safe for 4 hours
91dBA=safe for 2 hours
>100dBA= not safe over 1 minute
>127dBA= ear ringing begins immediately
>120dBC= immediate nerve damage in children
>133dB= physical eardrum distortion begins
>140dBC= immediate nerve damage in adults
>198dB= human death from shockwave
For more specific times: at SPL over 85dBA, +3dB change halves safe exposure time.
Generally, SPL under 80dBA is safe for prolonged periods of time, but I follow these personal guidelines.
–When working on a music project, I mix at 73-76dBA and listen back at 76-83dBA
–When listening to music at home, I usually listen at 76dBA or 83dBA if I am really rocking out.
Always wear earplugs to shows!! I recommend the Etymotic/Hearos/Mack’s/3M silicone, hi-fi/musician earplugs for moderate-volume shows or band practice. They are good for -12dB to -22dB. If you are up close at an arena show, or if you have a guitarist that refuses to turn down, then use foam earplugs (usually good for -28 to -33dB, but they also muffle the high-frequencies pretty badly).
I personally feel that club-owners should be held accountable for hearing-loss in their patrons. That is a controversial statement, and I understand that high SPLs are assumed at concerts, but that also assumes an old setup consisting of a large array of speakers front of house, usually next-to and over the stage… but in this day, it is only marginally more difficult/expensive to break the system and have top-fill, suspended horns and side-fill, wall-mounted woofers throughout the venue with time-delay compensation to keep the levels consistent throughout the room. That way there are not dangerously-high SPLs near the stage in an attempt to have sufficient loudness throughout the venue. It is ALSO quite possible to rig up a system post-mixer/pre-speaker with automatic volume compensation to keep SPLs within an acceptable range.
I believe that the venue-owners should assume patrons have no hearing protection, and keep the SPLs within a safe range according to the length of the concert. But even if those simple steps are not taken… generally, for club/small-hall shows, the club-owner/sound-guy is an A-hole if the volume ever exceeds around 110dBA more than a few feet from the speakers (since that would give a margin of a few minutes from someone without hearing protection — like someone at the bar going through the crowd to get to the bathroom, or a staff-member going through the crowd from say… the kitchen to the bar or something — to get from one side of the room to the other without damaging their hearing) or exceeds 140dBC EVER since that is NEVER safe.
When I used to mix live sound at a bar or club, I would assume 2 hours of total band playing time, and keep the band’s SPL under 90dBA @ a few feet from the speakers (and under 71dBA with the doors shut at the closest residential-zoned property after 9pm, which was Philadelphia noise code for clubs… that way if anyone complained, I could whip out an SPL meter and a copy of the 10-401 noise ordinance to show the cops that were in compliance) and the music between sets around 60-70dBA so that people don’t have to shout over the music to have a conversation (and to give their ears a rest).
CONCERNS FOR MUSICIANS:
In addition to the ambient SPL of a concert, musicians are at risk from solo sources. A Celestion Vintage 30 guitar speaker has a rated SPL of 98-100dB at 1 meter, so at it’s maximum rating of 60 watts, it should put out about 118dB before farting out… or about >124dB in a 4×12″ configuration (since dB are log-based and 10 log 4 = 6.021). A drum kit is about 115dB at the throne on a hard snare hit. Also, a concert grand piano can reach >110dB at the bench, and trained opera singers can sustain >120dB SPL at their mouths, and reach >130dB in bursts (which is why many veteran opera singers suffer from hearing loss since the attenuation from mouth-to-ear is only 7dB).