Crank it up, man!

Rock'n'roll is supposed to be loud. Is not just a childish attempt to rebel or a substitute for real art. There is something that sounds different when the music is loud. When the kick and the bass are physically shaking your body. There is something inspiring about how a guitar sounds when the amp is turned up to 11. It is not just a fad.

But sometimes you wonder, "is it too loud? Am I going to damage my hearing? How loud is too loud?"

The simple answer is that musicians are typically exposing themselves to levels that are OK for an audience... but too loud for the musicians. Let me explain...

There has been quite a bit of research put into how much volume our ears can take before it damages them. The standard benchmark is the OSHA guidelines:

           PERMISSIBLE NOISE EXPOSURES [1]
______________________________________________________________
                           |
 Duration per day, hours   | Sound level dBA slow response
___________________________|_________________________________
                           |
8..........................|                    90
6..........................|                    92
4..........................|                    95
3..........................|                    97
2..........................|                   100
1 1/2 .....................|                   102
1..........................|                   105
1/2 .......................|                   110
1/4 or less................|                   115
___________________________|________________________________

So, if you're going to be exposed to noise for 8 hours a day... you need to make sure the noise is less than 90 dBA to avoid damaging your hearing. On the other hand, if you want to crank it at a rock concert... you need to keep it below 95 dBA.[2]

That's great... but what the heck is a "dBA slow response?" First, here is a table with several relative loudnesses to help give you a feel:

   LOUDNESS OF TYPICAL EVENTS [3]
______________________________________________
        |
   dBA  | Equivalent event
________|_____________________________________
        |
    0   | threshold of hearing
   10   | rustle of leaves, a quiet whisper
   20   | average whisper
 20-50  | quiet conversation
 40-45  | hotel, theater between performances
 50-65  | loud conversation
 65-70  | traffic on a busy street
 65-90  | train
 75-80  | factory noise (light/medium work)
   90   | heavy traffic
 90-100 | thunder
110-140 | jet aircraft at takeoff
  130   | threshold of pain
140-190 | space rocket on takeoff
________|_____________________________________

"Cool... but what's a dBA?" See below.[4]

So, for a music performance (1-4 hours), the audience can take 95-105 dBA without damaging their hearing.

But for the musician, regular exposure 95-105 dBA will result in long-term hearing loss.

This is a real problem, because:

1. Musicians are taught to "practice to perform." That is, practice as if it was really the performance.
2. Balance, levels, and dynamics have to be set at performance volumes. Things literally sound different when you change the volume.[5]
3. Musicians love the way it sounds at performance volumes. Can't get enough.
   

Here's some tips for musicians to protect their hearing:

1. Ear plugs. Not the 35 dB instrustrial kind. Get some light 5-10 dB earplugs.
2. Turn it down for practice... especially if it is not on a performance day.
3. Turn down your MP3 player. Typically 50% or less. See this.
   

Be a man! Use earplugs.

Next post: Why does it sound different when I change the volume?

---

[1] 29 CFR 1910.95(B)(2), Table G-16 (link)
[2] For any of my friends at New Hope... don't freak. We've been measuring dBC. With our mix, 105 dBC is probably around 90 dBA.
[3] I found this list here, which attributes the Encarta 2005 encyclopedia.
[4] To be more specific, a dBA is the decibel reading that you get from a decibel (dB) meter that is set to the A-weighting and set to a slow response. A decibel (dB) is measures the air pressure that is stirred up by the noises. The A-weighting applies the principles of the "equal loudness curve", and it considers the fact that our ears don't pick up very low and very high frequencies very well. (More on that in a future blog post.) Most decibel meters that you buy will have the A-weighting available.
[5] This, too, is the equal-loudness curve... see [4].