Comment by gcv | Hacker News Reader

Comment by gcv | Hacker News Reader

The rules of thumb about "60% of maximum volume for 60 minutes" and "if you can't hear your surroundings, it's too loud" are nonsense. Dangerous volume settings depend on a headphone's sensitivity, the output device power, the headphone's isolation ability, and the recording. These parameters vary. Wildly.

A well-fitting isolating IEM can slice off 25dB of noise, more than enough to (mostly) eliminate background conversation noise at any location short of a hip restaurant. These IEMs tend to be so sensitive that they become earsplitting at a tiny fraction of the maximum output volume, way less than 60%.

Learn approximate dB levels of various sounds, compare various noise with a meter (even an uncalibrated app will give you a ballpark idea of what you're dealing with), and listen to music at an average 65dB or less (this will obviously vary with dynamic range of your music; occasional 80-85dB peaks won't kill your hearing).

One trip to a dance club or rock concert without earplugs (100-110dB on average in my experience, 120+ has been known to happen) will do more hearing damage in a few minutes than a lot of headphone listening while working. I'm pretty sure the busy street near my home routinely hits a 90dB average at rush hour, solidly in the danger zone compared to reasonable headphone use.

Edit: To learn more, read the following:

- http://www.rane.com/pdf/old/note100.pdf

- http://nwavguy.blogspot.com/2011/09/more-power.html

It might be helpful if you could offer citations for that. I find it hard to judge these competing claims

None of that comment seemed unreasonable to me - I've had large over-ear sets of headphones that require me to turn the volume up pretty high. It takes more to drive them, that's why some people own headphone amps.

Compare that to IEM's like the Sennheiser cx 300 - 5% of max volume at my computer might be too loud.

And it would surprise me if headphone usage at reasonable volumes is worse than going to loud concerts, even if you use headphones for long periods of time. If I'm at a concert or a loud bar for an hour or two, my ears feel really fatigued afterwards, everything seems quieter. I've never turned up headphones loud enough to experience that.

If anyone is curious, this is what the sensitivity measurement is on headphones: https://en.wikipedia.org/wiki/Headphones#Sensitivity

TL;DR "The sensitivity of headphones is usually between about 80 and 125 dB/mW and usually measured at 1 kHz." and note that since dB is logarithmic, every 6dB is 2x the energy (human-perceived "doubling of volume" is typically ~10dB; see also: https://en.wikipedia.org/wiki/Fletcher%E2%80%93Munson_curves )

Sure. I added some reading material links to my comment. The Rane document has an OSHA safe sound levels table at the end, a good reference. Keep in mind that the dB scale is logarithmic if you want to crunch numbers on device power, headphone sensitivity and impedance, and resulting SPLs.

Here's OSHA and NIOSH:

https://www.osha.gov/SLTC/noisehearingconservation/

TL;DR: NIOSH would recommend limiting the 8 hour exposure to less than 85 dBA. At 100 dBA, NIOSH recommends less than 15 minutes of exposure per day. NIOSH also recommends a 3 dBA exchange rate so that every increase by 3 dBA doubles the amount of the noise and halves the recommended amount of exposure time.

15 minutes is 7 doublings away from 32 hours, i.e. constant exposure. So, 100-(7*3)= 79dBA is safe, and 82dBA is safe for long-term exposure, and 85dBA is a limit at which you should have hearing protection.

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