Beat

In signal processing and wave theory, “beat” refers to a periodic variation in the amplitude of a wave resulting from the interference of two waves with slightly different frequencies. When two sinusoidal waves of nearly equal frequencies combine, they produce a phenomenon known as beats. The beat frequency is equal to the difference in frequency between the two original waves. This phenomenon is audible in sound waves as a pulsating or throbbing sound, and it is also observable in other types of waves, such as electromagnetic waves.