Page 45 - Zone Magazine Issue 015

FIG.3
FIG.4.1
FIG.2.1
FIG.4
" Before we jump into the world of sound waves and sound synthesis, we first need to understand what sound actually is. "
FIG.5
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Within these complex sounds, are different types of frequencies which help influence our ability in determining the pitch and timbre of a complex sound. Firstly, you have what is known as the fundamental frequency. This frequency acts as the base of your sound and is commonly the lowest frequency of a sound. The fundamental is also what the brain identifies as the pitch of the sound. Fig. 4 shows a visual of a pure tone sine wave displayed on a spectrum analyzer. If we now look at fig 4.1, you can see that there are tones higher than the previously mentioned pure tone sine wave.
The lowest tone is now marked as the Fundamental, whereas every frequency higher that the fundamental are called Overtones. The last element to describing the harmonic content of a sound, are the Harmonics of a sound. The Harmonics of a sound, are the frequencies which are integer multiples of the Fundamental. For example, if your fundamental frequency was 150Hz, this could be written as 1f meaning 1 times the fundamental.
If we look at fig. 5 we can see the
fundamental frequency is 100Hz, following that are the frequencies 200Hz, 300Hz, 400Hz etc.. These are the Harmonics and can be written as 2f, 3f, 4f etc.. since they are integer multiples of f (Fundamental). These frequency multiples, are what make up popular waveforms such as Saw Waves, Square Waves, Triangle Wave etc.
Hopefully, by now you have learned and understood the basics of Sound. We have covered a lot in this article which for some people might be a bit overwhelming. To help you out I have included a short synopsis of some keywords and points you can refer to whenever you get confused. Next month we will cover the creation of waveforms you would use in music production and would commonly find on most synthesizers.
Important Points:
* Sound is the vibration of a Gas, Solid or Liquid.
* The 3 properties of sound as perceived by the brain are, Pitch, Loudness & Timbre.
* A Wave Cycle is where a sound begins at the zero crossing point, completes one full cycle and then repeats. * Hertz (Hz) is the scientific term to describe the frequency of a sound which is determined by the amount of cycles in 1 second.
* The Human Hearing Range is between 20Hz and 20,000Hz or 20kHz (kiloHertz)
* A Spectrum Analyser displays The Frequency vs. The Amplitude of a sound.
* 1 Octave = 12 Semi-Tones.
* Loudness is measured using units called Decibels (dB).
* Timbre can be used to describe the Tone or Texture of a sound.
* A Complex Sound is a sound made up of more than one tone.
* The Fundamental Frequency is the lowest tone in a sound.
* Overtones are every frequency over the Fundamental.
* Harmonics are integer multiples of the Fundamental Frequency.
NEXT ISSUE:
The Fundamentals of Sound Pt. 2
ESSENTIALDANCEMUSIC 45