Sound synthesis algorithms are typically described and implemented using primative signal processing “building blocks” called unit generators.
Each unit generator has specific control and/or signal inputs, as well as control and/or signal outputs.
Unit generators support an object-oriented approach to sound synthesis.
Sound synthesis algorithms are graphically represented using signal flowcharts, such as that shown in Fig. 6.
Figure 6:
A signal flow diagram for two sinusoidal oscillator synthesis.
Each unit generator has its own specific symbol in a flowchart.
The oscillators in Fig. 6 are shown with inputs for amplitude and frequency (a phase input is not shown but is normally provided by the unit generator implementation).