Reflection of Sound
We have studied the reflection of light in earlier classes. Just like light, sound can also be made to change its direction and bounce back. The bouncing back of sound when it strikes a hard surface is called reflection of sound. Hard surfaced like walls, metal sheets, plywood, etc., reflect sound waves. Sound is reflected in the way as light. The laws of reflection of light are obeyed during the reflection of sound. The reflection of sound, however, does not require a smooth and shining surface like that of a mirror. Sound can be reflected from any hard surface, whether smooth or rough.
The reflection of sound follows the law "angle of incidence equals angle of reflection", sometimes called the law of reflection. The same behavior is observed with light and other waves, and by the bounce of a billiard ball off the bank of a table. The reflected waves can interfere with incident waves, producing patterns of constructive and destructive interference. This can lead to resonance called standing waves in rooms. It also means that the sound intensity near a hard surface is enhanced because the reflected wave adds to the incident wave, giving a pressure amplitude that is twice as great in a thin "Pressure Zone" near the surface.
This is used in pressure zone microphones to increase sensitivity. The doubling of pressure gives a 6 decibel increase in the signal picked up by the microphone. Reflection of waves in strings and air columns are essential to the production of resonant standing waves in those systems. Echoes are produced due to the reflection of sound.