So, what is
sound?
If a tree falls in the
forest and no one is there to hear it, does it still make a sound?.
No. Until there is
an ear there is no sound! Sound only qualifies as such when it is 'received'. Up
to that point it is simply vibration moving through the in the air.
Some will
disagree with me :)
Characteristics Of Sound by: Ryan Fyfe
Sound in brief but remarkeable terms is a vibration, that our ears percieve
by the sense of hearing.
Most commonly vibrations travel to our ears via the air. The ear then
converts these sound waves into nerve impulses that are sent to our brains,
where the impulses become sound.
To say all that in a more technical language: Sound "is an alternation in
pressure, particle displacement, or particle velocity propagated in an elastic
material" (Olson 1957). Sound is also a series of mechanical compressions and
rarefactions or longitudinal waves that successively propagate through media
that are at least a little compressible.
What causes sound waves is known as "the source of waves". Examples of sounds
sources is: A violin string that vibrates upon being bowed or plucked. The four
characteristics of sound are frequency, wavelength, amplitude and velocity.
The frequency of sound is the number of air pressure oscillations per second
at a fixed point occupied by a sound wave.
The amplitude is the magnitude of sound pressure change within the wave.
Basically this is the maximum amount of pressure at any point in the sound wave.
A sound wave is caused literally by increases in pressure at certain points
causing a "domino effect" outward, the higher pressure points are the crests in
a http://www.mysoundsite.com - sound wave, and behind them are low pressure
points which tail them. These are known as the troughs on a wavelength graph.
Sound's propagation Velocity depends largely on the type, temperature and
pressure of the medium through which it propagates. Because air is nearly a
perfect gas, the speed of sound does not depend on air pressure. The frequency
range of sound that is audible to humans is approx. between 20 and 20,000 Hz.
This range of course varies between individuals, and goes down as are age
increases.
Sounds will begin to damage our ears at 85 dBSPL and sounds above
approximately 130 dBSPL will cause pain, as a result are known as the:
"threshold of pain". Of course again this range will vary among individuals and
will change with age.
About The Author
Ryan Fyfe is the owner and operator of My Sound Site -
http://www.mysoundsite.com,
which is the best site on the internet for all sound related information.
Feel free to reprint this article as long as you keep the article, this
caption and author biography in tact with all hyperlinks.
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