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  protecting your  >> hearing
Dr. Christopher J. Keyes - hearing
Protect your hearing:  As musicians, what could be more precious than our hearing? Our ears are absolutely amazing instruments. Protect yours as you would a Stradivarius. Noise Induced Hearing Loss NIHL is a serious, common, and tragically avoidable problem.

According to Dr. de Laat of the Audio Engineering Society, and the World Health Organization standards permanent hearing loss can result from exosure to:
 - 85 dB SPL (A) for 2 hours = great chance
 - 90 dB SPL for 1 hour = great chance
 - 100 dB SPL for 15 minutes = very great  
   chance
102 dB SPL (A) for 2 hours = a Christian pop concert in Hong Kong*
Note hearing and decibels are on a logarithmic scale, doubling every 3 dB.  So  88 dB is twice as loud as 85 dB, 91 dB is 4 times as loud, 94 dB 8 times as loud, and 102 dB is more than 50 times louder than 85 dB.
 Things you should do:
  • Buy good quality ear plugs and/or your fingers in your ears if things are too loud.
  • Invest in the best quality headphones you can afford: you don't have to turn them up very loud to hear details clearly. (I personally would compare them to the Sennheiser PX200-II, which sound excellent to my ears).
  • Download an SPL meter for your cell phone and if possible, calibrate it to a real SPL meter. Use it to see just how loud things really are.
  • SPEAK UP if your ears are being assaulted.
Listen to Julian Treasure speak on Sound Health at TED
"The softest sound you can perceive moves your eardrum just 4 atomic diameters. The loudest sound you can hear is a trillion times  more powerful than that."
How to spot a good live sound engineer?
  • They wear ear protection if they work with high SPL audio. They know they are exposed to higL levels for longer periods of time than their audience, they are aware of the danger, and they value good hearing.
  • If you ask them what SPL levels they feel are excessive and pose a threat to the audience they will have a coherent answer.*
  • They will have had their hearing checked regularly.
It is cheifly their judgement on how loud things will get and what is safe. If they don't wear ear protection, have their hearing checked, or have some educated ideas on safe levels for different materials, don't trust their judgement (or hire someone else).
*In truth it's a complicated question. Everyone's hearing is different and for obvious reasons its not possible to conduct a controlled study in which subjects are exposed to high SPLs and their level of permanent hearing loss carefully measured. It also depends greatly on the material. A classical concert may have momentary peaks of up to 125 dB, but the basic material quickly comes back to reasonable levels and the ear easily recovers. Highly compressed pop music, on the other hand, may reach a sustainded 105dB but only ever come down to 95dB, never giving the ear a chance to recover. This is a huge threat.

How to spot a bad live sound engineer?
Look at the headines: "A rock music fan took his life after battling tinnitus, an inquest heard yesterday. Father-of-two Robert McIndoe, 52, was unable to sleep for three months after attending a concert that left him with a permanent  ringing in his ears."
Guidelines issued in the UK and central europe agree that sustained levels of over 85dB are cause for concern, over 90dB cause for serious concern, and over 95dB dangerous