Subject: Robinson/Dadson curve equations? From: Bruce Walker <walkerb(at)RUF.RICE.EDU> Date: Tue, 19 Dec 2000 11:45:30 -0600Happiest of holidays! Could anyone possibly provide a source for *equations* that accurately represent the equal-loudness contours from Robinson & Dadson (1956), or subsequent similar works? Basically, I need to be able to plug a frequency into an equation (on the fly), and have it spit out the "corrected" loudness that I need to use in order to match a given reference tone. (I want a whole series of tones to be equated for loudness.) If the actual equations are not available, then perhaps a set of data that I can stick into Maple to derive the equations would be fine, too. Note that R&D _do_ provide quadratic equations that cover parts of the curve ranges. However, I'd estimate that a 6-degree polynomial would give a better approximation to the the curves over the entire data ranges. Six or eight degree polys were obviously not calculable by hand, which is why R&D used quadratics. Thanks in advance, --Bruce ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Bruce Walker, Ph.D. (PC86-88) Rice University Psychology Dept. email: walkerb(at)rice.edu 6100 Main St., Houston, TX, 77005 ph: (713) 522-2969 (home) (713) 348-3772 (office) http://www.owlnet.rice.edu/~walkerb (713) 348-5221 (fax) ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~