The principle of linear superposition and interference phenomena

Constructive noise cancellation. Any sound resonances that we are subjected to result from constructive and destructive interference of sound waves as they travel through a medium — typically air. We hear the effects of constructive interference every day. Any time we listen to music, we hear the effects of the resonant frequencies as they interfere constructively to form standing waves from the musical instruments. The resonance and standing waves are vital to our hearing; however, there are times when the destructive interference of sound waves can play a significant role. Our hearing is one of our most important senses and excessively loud noise and sounds can cause permanent damage to our hearing.