Instruction Manual

526 Editing Audio
Digital Audio Fundamentals
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 played. Rather, all these vibrations are
added together to form a complex or composite sound that our ear
perceives as a single tone.
This composite waveform still doesn't account for the uniqueness of the
sound of different instruments. For example, stringed instruments usually
have a resonator. In the case of the guitar, the resonator is the big block of
hollow wood to which the string is attached (the guitar body). This has a
Fundamental
frequency (1f)
100% amplitude
2x fundamental (2f)
50% amplitude
3x fundamental (3f)
33% amplitude
4x fundamental (4f)
25% amplitude
5x fundamental (5f)
20% amplitude