Click on a letter or number to jump to listings of terms that correspond. [ 5 | A | B | C | D | E | F | G | H | I | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y ] Term Definition Demo Absorption In acoustical absorption, sound energy is converted into heat. See: Resistive Absorbers, Diaphragmatic Absorbers, Resonant Absorbers, Absorption Coefficient, Sabine. Absorption Coefficient The proportion of incident sound that is absorbed by a surface. Usually this is expressed as a number between 0 and 1, or a percentage. In most materials, the amount af absorption changes with the angle of incidence. The specification is normally a 'random incidence' measurement.