A diagram showing four sinusoids of frequencies 2000, 2200, 2400 and 2600 hertz (green, purple, orange and red). Also shown is the summed signal (black) and the sinusoid with the same period as the beat frequency (<i>f</i><sub>0</sub>, 200 Hz). Above is the spectrum of the signals.
<a href="//commons.wikimedia.org/wiki/User:Inductiveload" title="User:Inductiveload">Inductiveload</a>
<span class="int-own-work" lang="en">Own work</span>