In an earlier post, “WAKE UP! WAKE UP! Ignoring Noise is Dangerous to Your Health” I wrote about how our brains are brilliantly engineered to filter out and ignore extraneous sound.
“…Our brains are masters at filtering out unwanted sounds. We need to do this in order to focus on what’s important to us. If we could not filter out unwanted sound we’d go nuts. Can you imagine having an important conversation with a friend if you could not help but pay equal attention to all the other conversations, noises, and music that was occurring around you? Long, long ago, we had to filter out little more than nature sounds like wind, water and rain. Now we must filter out much more noise. It’s got to the point where our brilliance at ignoring unwanted sound is our poison. All this louder noise is stressing our bodies. The constant clangor of urban life is causing our bodies to release our fight or flight hormones – adrenalin and cortisol. These are meant for emergencies, not to be part of a continuous diet.”
I thought I’d list off a small handful of everyday perpetrators of unhealthy noise that we encounter most days in an urban environment plus some less common examples that people rarely or never experience.
The numbers and items I am listing are from Julian Treasure’s excellent book Sound Business. I recommend this book highly for anyone interested in improving their business’ or personal environment’s soundscape. The measurements are in decibels or dB. Things to know as you read. The decibel scale is exponential, like the Richter scale used for earthquakes. There is a big difference between 70 and 80 dB and it is perceived as a doubling of the loudness to our ears. 85 dB is the level at which continuous exposure results in hearing damage. The listed dB levels are calibrated to indicate what the level would be one metre away from the sound source. The book includes a much more comprehensive list.
0 dB – Beginning of hearing – a mosquito 10 feet away
40 dB – Whisper
40-60 dB – Normal conversation
80 dB – Heavy Traffic at 10 Metres
85 dB – Beginning of hearing dammage, earplugs should be worn
100 dB – Typical car or house stereo at maximum volume, a loud shout
110 dB – Night club on the dance floor
120-130 dB – front row at a rock concert
140 dB – all frequencies are painful; extremely damaging to hearing no matter how short the time exposure
147 dB – Formula 1 racing car
150 dB – rock concert “The Who”
163 dB – Whale song
191 dB – Explosion – 1 lb bomb or grenade
190 – 195 dB – Human Eardrums rupture 50% of the time
198 – 202 dB – Human death from sound (shock) wave alone
215 dB – Thunder from the largest “Positive Giant” lightning strikes
235 dB – Earthquake 5.0 on Richter scale
286 dB – Mt Saint Helens volcano eruption blew down trees 16 miles away and blew out some windows in Seattle-Tacoma 200 miles away.
310 dB – Krakatoa Volcano Eruption, 1883. Cracked one foot thick concrete at 300 miles; created a 3,000 foot Tsunami; heard 3,100 miles away…rocks were thrown to a height of 34 miles. Dust and debris fell continuously for 10 days after blast…shock (sound) waves “echoed” around the earth 36 times and lasted for about a month!
I’ve begun to do some of my own investigating. While it’s not precisely accurate, it gives you the world of things. I downloaded a free app to my iPhone called Decibel 10th. Then I went to several local coffee shops and they all had readings of between 75 and 85 dB. I measured from a variety of locations in each venue. What was most shocking was that the worst one was nearly empty.
Then I took a measurement at a pub in False Creek. I was attending a networking event. The level there was 95 dB!
All of these facilities are unnecessarily loud simply because absolutely no attention has been paid to the acoustic design of the venue. All the surfaces are reflective – concrete, exposed ceilings, tile or concrete floors, bare walls, wall to wall glass, metal or wood tables and chairs. There is nothing in the space to absorb sound.
The consequences are largely tolerated and ignored at great expense: Damaged hearing, an inability to communicate effectively, and the continuous release of damaging stress hormones.