How loud is too loud?
Safe exposure to loud noise, including music, depends upon the intensity of the sound and duration of the exposure.
When I first posted this article (in March 2004) I was advised by a correspondent that OSHA guidelines (retained below for comparison) are now considered too lax for adequate hearing preservation. I finally found the NIOSH guidelines (also adopted by ANSI) which are based upon actual sound energy. In other words a 3dB increase in sound level reduces the safe exposure time by a factor of two.
It's interesting to note that the NIOSH specs consider exposure to greater than 115 dB sound unacceptable for any duration. This sound level is achievable by many tube guitar amplifiers. What's more interesting is that sound in the 90 to 100 dB range, which is within the range that guitarists tend to consider "restrained", still has a remarkably short safe exposure time.
Also note that the OSHA guidelines spec A-weighted measurement which further underestimates the exposure level. At the sound levels of interest to guitarists a C-weighted measurement must be used.
Keep in mind that sound exposure is cumulative. You can look up the measurement techniques and formulas elsewhere if you care. Loud stereos, highway noise in an open vehicle, power tools and many other common noisemakers all contribute to your daily noise exposure.
As a musician, it's a good idea to take the following guide to heart if you want to preserve your most valuable assets: your ears. The first step is awareness: invest $50 or so in a sound level meter and bring it to rehearsals and gigs. The second step is prevention: get earplugs that will reduce the sound level to somewhere in the mid-80 dB range.
Earplugs are rated for how much they attenuate sound, also measured in dB. Fortunately the math is simple. A set of 20 dB earplugs reduces the sound at your ears by 20 dB from whatever it is in the room.
- Example 1: If you measure the room at 115 dB then your ears will be exposed to 95 dB through 20 dB earplugs. At that level you're safe for less than an hour's exposure.
- Example 2: The same 115 dB room level becomes 85 dB at your ears through 30 dB earplugs. At this level your ears are safe for eight hours' exposure, longer than you're likely to play in a day.
- Example 3: At 105 dB in the room, a set of 20 dB earplugs will drop the level to 85 dB at your ears. Again, this level is safe for 8 hour's exposure.
- Example 4: At 95 dB in the room - a level which is still way above conversational volumes - a set of 10 dB earplugs brings the level down to 85 dB at your ears. This is a significantly lower volume than you'll find in most rehearsal rooms or clubs, yet the safe exposure time without earplugs is less than an hour.
Because musicians complain of feeling "disconnected" when wearing high-attenuation earplugs, it's important to reduce the room SPL such that lower-attenuation plugs can be used.
Take care of your ears when attending concerts and clubs. There are no regulations regarding noise exposure in entertainment venues, yet some of the worst abuses occur in small halls and clubs. Assume the worst and wear high-attenuation earplugs when present at a venue which plays loud music.
|Duration per day||Sound level (dB, C weighted)|
|7 min 30 sec||103|
|3 min 45 sec||106|
|1 min 52 sec||109|
Ref: NIOSH, ANSI
|Duration per day||Sound level (dB, A weighted)|
|15 min or less||115|
|7 min or less||120|
|3 min or less||125|
Ref: OSHA 1910.95