COMB FILTER
A FILTER which passes the entire frequency range except for a set of very narrow BANDs, spaced usually at equal distances (on either a linear or logarithmic scale). The roll-off at each of these frequencies is quite sharp, giving a diagram of the response of the filter the shape of a comb. A comb filter effect is found in PHASING (also called flanging) and in PINNA reflections.
Sound Example: A dynamically changing comb filter effect found in the environmental phasing of the sound of a seaplane taking off.
Head-related transfer functions (HRTF) for two subjects illustrating spectral colouration for increasing source elevation in the lateral plane. The sound was located 2 meters to the left of the subject and was moved from ear level (0 degrees) to an elevation 30 degrees above ear level (solid line: 0 degrees; long dashes: 10 degrees; short dashes: 20 degrees; dotted line: 30 degrees). From G. Kendall & W. Martens, "Simulating the cues of spatial hearing in natural environments," Proceedings of the 1984 International Computer Music Conference, used by permission of the authors.
