Robinson/Dadson curve equations?

[Bruce Walker <walkerb@xxxxxxxxxxxx>]

Happiest 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@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)
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