Grating, diffraction
- The principle now used to achieve diffraction of acoustical waves, analogous to optical grating by which light is broken into its component colors as when passing through a Prism.

Diffraction - The bending of a sound wave around an obstacle, or through an opening, such as slats. The scattering of sound Wavesat an object smaller than one wavelength, and the subsequent interference of the scattered wavefronts.