聲音係由啲發聲物件震動所得。發聲物件個主體震緊嗰陣，就會產生基頻音，同時啲主體之外嘅部分亦存在住反覆嘅震動，從而產生泛音。泛音就係決定發聲物件音色嘅關鍵之處，令人分得出唔同樂器，甚至係唔同人嘅聲線。所以根據音色嘅相異之處，就可以得出人類認知嘅聲音 － 男聲定女聲；高音、中音定低音；弦樂定管樂；等等。
Sound is produced by the vibration of some sound-emitting object. When the main body of the sounding object vibrates, the fundamental frequency sound will be generated, and at the same time, there are repeated vibrations in some parts other than the main body, resulting in overtones. Overtones are the key to determining the timbre of the sounding object, allowing people to distinguish the voices of different instruments and even different people. Therefore, according to the differences in timbre, we can derive human cognition of sounds—male and female voices, high and middle tones for bass, strings for wind music, and so on.