This program also part of the Hori is piece of Psi-spectrum software that combines two waves together to form a third, more complex wave.

If the frequencies of the two waves are fairly close, then a low frenquency effect will occur, known as beating. This is most prominent when the ampitudes of the two waves are also close.

The program will add two waves of your choice, emphasising the beat frequency in red (if it finds one!).