Two Sound Sources Interference

This simulation demonstrates the superposition of sound waves from two speakers, allowing students to observe constructive and destructive interference as well as beat phenomena when the sources have slightly different frequencies. By visualising wavefronts and listening to the combined signal at a movable microphone, learners can connect the abstract concepts of phase, wavelength, and frequency to audible effects.

Students can switch each speaker on or off, change the frequency of Speaker 1 (170‑850 Hz), detune Speaker 2 by up to ±40 Hz, and vary the separation between the speakers in multiples of the wavelength of Speaker 1. The microphone can be dragged to any position on the bench, and buttons let users locate the nearest loud or quiet points, display the full interference field, or pause the animation.

Through this interactive environment, learners develop an intuitive understanding of how frequency difference creates beats, how spatial separation influences interference patterns, and how phase relationships determine sound intensity at different locations.