A,E) Normalized VOHC for multi-tone Zwuis stimuli. B,F) Corresponding phase re: EC pressure. C&G) Normalized VOHC for single-tone stimuli. D&H) Corresponding phase re: EC pressure. The nonlinear analysis in this manuscript was done on two frequency regions: 1: sub-BF (orange band) and 2: BF region (yellow band). A-D) #728, runs 10,11, E-H) #712 runs 18,19.