Noise and Sound and Hearing Damage

Written By:
Henry P. Shotwell, CIH
Senior Vice-President
Atlantic Environmental, Inc.

According to legend, the Zen Master asks the student two questions: “What is the
sound of one hand clapping? and “If a tree falls in the forest, and no one is there,
does it still make a noise?” I don’t know if the student was able to answer, but I
can!

What is the sound of one hand clapping? The answer is: “No sound.” By
definition, hand clapping is an activity that requires two hands. But that’s not the
reason no clapping sound is made by only hand. The reason lies in the process by
which sound is generated. When you clap your hands, you are actually capturing
and compressing a small amount of air between your palms. This compression
of air creates a wave that reaches our eardrums and sets off the whole process of
detecting and interpreting these “sound” waves by the brain.

As to the tree in the forest, when the tree falls to the ground, trapping and
compressing air in the process, it creates sound. But does it create noise? Sound is
always produced by the alternating compression and decompression of air. Noise,
on the other hand is a term we use to make a value judgment about the sound we
are hearing. What is music (Beethoven’s 9th Symphony, for example) to my ears
is complete noise to my son, who thinks that the sounds created at a typical rock
concert have come to us from “On High.” So the answer to the second question
is: Sound is created, whether or not anyone is there to judge it as a sweet sound (a lumberjack, maybe?) or as a terrible crashing noise.

Where human beings are concerned, sound or noise can damage hearing, if very
loud and for a lengthy period of time. Whether the loud noise/sound is at home,
or at a rock concert, a set of headphones, or at the factory, the damage will be the
same if the volume, frequency and length of exposure is the same.

For work related noise exposures, there are set limits above which a person’s
hearing may be damaged if the time period is lengthy—say a year or more.
The “hearing conservation level” is 85 decibels (the OSHA standard is 29 CFR
1910.134) which can be found at http://www.osha.gov) under REGULATIONS.

Sound is sound but noise is a relative term—noise to some is nice sound to
another. Whether it is pleasant or not, it can damage your hearing.

Atlantic Environmental Inc
2 East Blackwell Street
Dover, NJ 07801
(800) 344-4414
(973) 366-4660
(973) 366-3116 Fax
info@atlenv.com

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