CAKEWALK Cakewalk SONAR, User Manual

Page: 317 / 610

317
Engl
ish
The displacement of the string changes as the string vibrates, as shown here:
The segment marked “A” represents the string as it is pulled back by the pick; “B” shows it moving back
towards its resting point, “C” represents the string moving through the resting point and onward to its
outer limit; then “D” has it moving back towards the point of rest. This pattern repeats continuously
until the friction of the molecules in the air gradually slows the string to a stop. As the string vibrates,
it causes the molecules of air around it to vibrate as well. The vibrations are passed along through the
air as
sound waves . When the vibrations enter your ear, they make your eardrum vibrate, and you
hear a sound. Likewise, if the vibrating air hits a microphone, it causes the microphone to vibrate and
send out electrical signals.
In order for us humans to hear the sound, the frequency of the vibration must be at least 20 Hz. The
highest frequency sound we can hear is theoretically 20 kHz, but, in reality, it's probably closer to 15 or
17 kHz. Other animals, and microphones, have different hearing ranges.
If the simple back-and-forth motion of the string was the only phenomenon involved in creating a
sound, then all stringed instruments would probably sound much the same. We know this is not true, of
course; the laws of physics are not quite so simple. In fact, the string vibrates not only at its entire
length, but at one-half its length, one-third, one-fourth, one-fifth, and so on. These additional vibrations
(
overtones ) occur at a rate faster than the rate of the original vibration (the fundamental
frequency ), but are usually weaker in strength. Our ear doesn't hear each frequency of vibration
individually, however. If it if did, we would hear a multinote chord every time a single string were