Superposition of waves to create an interference pattern can also be illustrated using sound waves. Here each loudspeaker serves as a point source of sound waves. Each speaker is generating sound of the same pitch (frequency). A microphone senses the sound and what you hear is determined by the intensity and frequency of the sound at the position of the microphone. If you listen to the sound generated by the two speakers as one moves relative to the other, you will hear different volumes of sound reaching the microphone. The volume settings of the speakers and the microphone are not changing. You are hearing the result of superposition of the sound waves at the position of the microphone.

As the speaker on the left is moved toward and then away from the speaker on the right, it passes through positions for which there is maximum constructive interference (sound level greatest) and destructive interference (sound level lowest) of sound waves at the location of the microphone.