A human cannot hear sound at a frequency of 100 kHz or sound at 102 kHz. But if you walk into a room in which two sources are emitting sound waves, one at 100 kHz and the other at 102 kHz, you’ll hear sound. Explain.
Solution 50E If two sound wave with different frequency interfere with each other, they will create beat. The frequency of the beat is the difference between the interfering frequencies. For example if two sound wave of frequency f and f interfere, then they will produce beat of sound 1 2 f = |f f | 1 2 Now in the case of given problem, the beat frequency will be f = (102 kHz) (100 kHz) = 2 kHz Since 2 kHz is in audible range, I will hear the sound of beat created by the two waves.