Safe Limits
The calculator
Don’t know how loud it actually is? Grab the NIOSH Sound Level Meter app first (free, iOS, built by the actual government researchers, tested against professional meters) and get a real reading. Then put that number in below along with what’s on your earplug package.
Safe exposure calculator
Realistic fit uses OSHA's derating for NRR ((NRR−7)÷2) and HSE's 4 dB derating for SNR. Safe time uses the NIOSH limit: 85 dBA for 8 hours, halved for every 3 dB above that. Not medical advice.
How long can you actually take it?
The science here is settled enough to be useful. NIOSH (the US research agency for occupational safety) says 85 dBA for 8 hours is the limit, and every 3db louder cuts your safe time in half:
| Level (dBA) | Safe exposure time | Real-world example |
|---|---|---|
| 85 | 8 hours | Busy restaurant, city traffic |
| 88 | 4 hours | Loud bar |
| 91 | 2 hours | Louder bar, some gyms |
| 94 | 1 hour | Quieter club |
| 97 | 30 minutes | Typical club |
| 100 | 15 minutes | Near the soundsystem |
| 103 | 7.5 minutes | Big festival stage |
| 106 | ~4 minutes | Front row territory |
| 109 | ~2 minutes | The peaks I’ve measured |
NRR explained (the math behind it)
The number on the package is not the protection you get. The math: take the NRR rating number and subtract 7. Then take that number and divide by 2. That’s the number of decibels that will actually be reduced for a typical real-world fit.
An example: my earplugs have a NRR of 23. Subtract 7 to get 16, divide by 2 to get 8db of actual level reduction.
Why so brutal? The subtract-7 converts the lab’s C-weighted test to the A-weighted levels you’d actually measure in a venue, and the divide-by-2 is OSHA’s derating because almost nobody gets the right fit. If you’re meticulous about putting them in (roll the foam plug down, pull your ear up and back, hold it while it expands), you can get closer to NRR minus 7 without the halving. Foam plugs seated deep and used correctly are the main case where people actually approach the label.
What’s an SNR?
One main difference between NRRs and SNRs is geography. In the U.S. NRR ratings are used. Within the European Union and the U.K., SNR ratings are typically used. SNR ratings also tend to read a few decibels higher than NRRs for the same plug. It’s the same basic idea. The UK’s HSE says to take about ~4db off the label for real-world use.
How to deal with all this at a show
Take breaks. Get out of the sound for a while and you’ll stress the hairs in your ears less. Find a place to get out of the sound. Venues that don’t let you go somewhere that is around 85db are set up poorly. The exposure math is cumulative and breaks actually buy you more time in front of the speakers.
Match the plug to the moment. Focus on the acts you really want to hear and use the lighter musicians earplugs for those. I use the strongest foam plugs (33 NRR is the highest I’ve found, a real-world drop of about 13db) for everything you don’t care about hearing as much or when your ears are already a little cooked.
The ringing test. If your ears are ringing when you leave a party, and it resolves within 2 days to the way it was before, you are likely fine and it was just the nerves in your brain responding to the audio activity. If it persists longer than that, it’s possible you’ve done some damage. I’ve had some episodes that resolved in a week, and some of the worst that took 6 months or longer. Hopefully you never have to deal with that because you are protecting your hearing.
Not medical advice. See the disclaimer.