Reflection of Sound

What is a reflection?

A reflection is the change in direction of a wavefront at an interface between two different media so that the wavefront returns into the medium from which it originated. For sound waves, this occurs when the waves encounter a boundary that does not absorb all of the sound energy.

Measuring Reflections:

The reflection of sound is primarily measured by the angle of reflection, which is equal to the angle of incidence. This can be expressed as:

θi = θr

Where: θi = angle of incidence θr = angle of reflection

Both angles are measured from the normal (a line perpendicular to the reflecting surface at the point of reflection).

Figure  showing the reflection of a wave on a flat surface

The angle between the incident wave and the normal (marked θ on the left) is equal to the angle between the reflected wave and the normal (marked θ on the right). This is the essence of the law of reflection for sound waves.

This principle holds true whether we're dealing with small distances (like sound reflecting in a small room) or large distances (like echoes in a canyon). The angles remain the same regardless of the scale.