File:Equal-loudness contours.xlsx

Parameters and equation for equal-loudness contours, including Fletcher-Munson, ISO 226:2203, ITU-R BS.468, and IEC 61672 (dB(A), dB(B), dB(C), dB(D)). Unfortunately, I could not find a public source with data for Robinson-Dadson/ISO 226:1987/ISO 226:1961.