Which phenomenon occurs when two sets of waves with slightly different frequencies overlap?

When two sets of waves with slightly different frequencies overlap, the phenomenon that occurs is referred to as beats. This occurs because the waves interfere with one another constructively and destructively at different points in time, leading to a variation in the amplitude and intensity of the resultant wave. The result is a rhythmic fluctuation in sound intensity that corresponds to the difference in frequencies of the two waves.

When the waves are in phase, they constructively interfere, creating a sound that is louder (higher amplitude). When they are out of phase, they destructively interfere, leading to a softer sound (lower amplitude). The frequency of these fluctuations is equal to the difference between the two original frequencies, creating what you perceive as a beat. Understanding this concept is essential in music and acoustics, where tuning instruments involves manipulating frequencies to create the desired beat effect.

Resonance refers to a condition where a system naturally vibrates at certain frequencies, often leading to increased amplitude but does not involve two different frequencies interacting in the same way as beats. Interference can occur without the specific rhythmic pattern identified in beats, and diffraction relates to the bending of waves around obstacles, which is unrelated to the interaction of two frequencies.