For surfaces large compared to the wavelength of impinging sound, sound is reflected much as light is reflected, with the angle of incidence equaling the angle of reflection.
A transformation of the x-y plane that moves each point to the opposite side of a fixed line, called its axis, along the line perpendicular to the axis so that the resulting point is the same distance from the axis as the original point.
If waves are incident upon a reflecting surface (e.g. mirror, harbour wall, etc.) they will obey the law of reflection which states:
angle of incidence = angle of reflection, where the angles are measured from the surface normal.
When the energy is scattered in only one direction, where the angle of incidence equals the angle of reflection, the scattered energy is generally called a specular reflection. In a specular reflection, most of the energy is concentrated into a very short period of time.
When the energy is scattered uniformly in many directions and temporally dispersed, the scattered energy is called a diffuse reflection. In a diffuse reflection the energy is distributed over a longer period of time than in a specular reflection.
- Further reading:
- Advanced Physics for You, , Nelson Thornes
- Acoustics and Vibrations Animations A collection of animations produced by Daniel A. Russell, Ph.D., Associate Professor of Applied Physics at Kettering University.