音源，即为音的发生源。

硬件音源，呈现方式以合成器、电子琴、电子管风琴、之类的电子乐器最为常见，硬件内置音源规格，拥有庞大的声库，最杰出音色采样，市面上的游戏主机、电脑、电话等都有内置。

软件音源，依据MIDI协定接口运行，需要有软件的支持，常见格式为VST，音色优劣单纯以开发商采样水准决定，优秀的音源可以达到以假乱真的效果。

声音合成有下列的发声原理：

A sound generator is a vibrating object which produces a sound. There are two main kinds of sound generators (thus, two main kinds of musical instruments).

A full cycle of a sound wave will be described in each example which consists of initial normal conditions (no fluctuations in atmospheric pressure), an increase of air pressure, a subsequent decrease in air pressure which brings it back to normal, a decrease in air pressure (less pressure than initial conditions), and lastly, an increase which brings atmospheric pressure back to normal again. Therefore, the final conditions are the same as the initial, at-rest conditions.