Reflection of Sound Waves

 

Reflection of Sound

Reflection of sound is similar to the reflection of light. The reflection of sound obeys the following laws of reflection

• The angle of incidence is equal to the angle of reflection.
• The incident sound, the normal sound and the normal sound all lie in the same plane.

When a sound hits a hard surface, it reflects back to its source. This reflection of sound is otherwise is called an echo. Hard surfaces have a tendency to reflect sound while soft surfaces absorb sound and silence them. If the frequency of the sound wave is low, then the sound wave will not get reflected. Sometimes, we hear multiple echoes from a source of sound if the area is large and has multiple reflecting surfaces such as valleys and huge empty rooms. This phenomenon is known as reverberation.

Reflection of  Sound Waves

Like light, sound also follows laws of reflection, it bounces off the surface of solid and liquid.

Echo

The phenomenon where a sound produced is heard again due to reflection is called an echo.
E.g. Clapping or shouting near a tall building or a mountain.

To hear a distinct echo sound, the time interval between the original and reflected sound must be at least 0.1s, as sound persists in our brain for about 0.1s. The minimum distance for obstruction or reflective surface to hear an echo should be 17.2 m. Multiple echoes can be heard due to multiple reflections.