BM tuning curves for varying sound stimulus levels (left) and the corresponding closed-loop sensitivity derived from those measurements (right) in the basal turn mammalian cochlea.

<p>The left panel (<b>A</b>) is BM displacement relative to stapes from Nuttall and Dolan <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0045640#pone.0045640-Nuttall1" target="_blank">[4]</a> in guinea pigs; (<b>C</b>) is BM displacement relative to pressure at ear canal in chinchilla from Rugerro et al. <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0045640#pone.0045640-Ruggero1" target="_blank">[5]</a>; (<b>E</b>) is BM displacement re pressure from Cooper and Rhode <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0045640#pone.0045640-Cooper1" target="_blank">[23]</a> also in chinchilla; and (<b>G</b>) is BM re stapes from the model predictions in Ramamoorthy et al. <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0045640#pone.0045640-Ramamoorthy1" target="_blank">[8]</a>. The right panels (<b>B</b>), (<b>D</b>), (<b>F</b>), and (<b>H</b>) show the corresponding closed-loop sensitivities. In (<b>A</b>)–(<b>F</b>), the numbers on the plot indicate the stimulus level in dBSPL; in (<b>G</b>) and (<b>H</b>), the numbers represent percentage of maximum MET conductance slope vs. HB displacement used in the model. From all four datasets, the BM tuning curves demonstrate shift in peak frequency (half-octave shift) with changes in stimulus level, whereas the closed-loop sensitivities do not.