(after Baker and Rosen, 2006)
This figure illustrates auditory filter shapes derived by Baker and Rosen (2006) using simultaneous notched-noise masking. In that study filter shapes were measured over a range of frequencies and levels and parameters for a fitted shape that was made up of a ROEX(p,w,t) model on the low frequency side and a ROEX(p) model on the high-frequency side. For the low-frequency side the 'w' parameter varied with tone level, and equations were derived to explain how the different parameters varied across frequency.
(replot of this data with a normalised gain at 0.4 x centre frequency)Richard J. Baker, Stuart Rosen; Auditory filter nonlinearity across frequency using simultaneous notched-noise masking. J. Acoust. Soc. Am. 1 January 2006; 119 (1): 454–462. https://doi.org/10.1121/1.2139100