ABSTRACT
Audio signals can be synthesized by using mathematical functions. There are many basic signals used in audio as "test" sound waves or with synthesizers. This chapter explores how an array of time samples can be processed by a built-in function to create various signals. An audio signal contains one, or more, frequencies at a given time. It can be complicated to determine which frequencies are contained in a signal based on the waveform. The frequency spectrum provides a way to see the amplitude of separate, individual frequencies. There are many audio signals that repeat a pattern of motion. Each repetition is called a cycle, and the time length of a cycle is called the period. Therefore, signals with this behavior are periodic signals. One basic periodic signal is the sine wave. It represents the motion in a single dimension for a signal with a phase angle that rotates at a constant rate.
