Three mel scales, derived from fractionation data, and representing three differential noise conditions are obtained. It is found upon comparison that the presently found no‐noise function differs in no essential manner from the generally accepted mel scale advanced by Stevens (1940). However, upon the introduction of a wide‐band masker, the shape of the mel function becomes more positively accelerated. In general, when holding the intensity of the masker constant, this acceleration is inversely related to the sensation level of the experimental tones above masked threshold, and is not frequency dependent. Although this relationship is not dependent upon frequency per se, the magnitude of pitch shift increases with frequency.