Information Transmission in the Auditory Brainstem Figure 10. Temporal and spectral analyses of responses to /e/ of high-sync and Group 3 VCN neurons. Panels A–C display period histograms obtained from responses of three high-sync neurons whose CF is indicated in each panel. Panel A recordings originate from the ventral acoustic stria. Panels G–I contain period histograms computed from responses of three VCN neurons (Group 3; CF indicated in each panel). Panels D– F (black continuous lines) and J–L (black continuous lines) show result of Fourier analysis obtained from responses shown in panels A–C and G–I, respectively. Dashed lines in panels J–L illustrate PSDs from three other VCN neurons (Group 3; CF indicated in each panel). doi:10.1371/journal.pone.0044286.g010 the neurons’ responses used in the histograms in Figs. 10G, 10H and 10I are plotted with red thick lines in Figs. 11A, 11C and 11E, respectively. SACs of high-sync neurons in Fig. 11 reveal the ability of those neurons to encode in their spike times the frequencies corresponding to f0 and F1, as indicated by the oscillations’ periods and the larger size of the oscillations at 10 ms. By contrast, SACs of the Group 3 neurons consist mostly of a sinusoid with period equal to 1/F1. Individual peaks in SACs of high-sync neurons are also narrower than peaks in SACs of Group 3 neurons. CIs and THDs of high-sync and Group 2 neurons (‘‘up’’ triangles in Figs. 11B and 11D, respectively) are larger in general than the corresponding values in Group 3 neurons (‘‘down’’ triangles in Figs. 11B and 11D, respectively). VCN neurons’ and ANFs’ responses to whispered vowels were registered only in the cat. Only responses to /i/ will be presented here since they constitute the most complete set of recordings. (Fig. 12A shows the PSD analysis for this vowel.) Dot raster plots of the responses of a high-sync neuron and an ANF to /i/ are shown PLOS ONE | www.plosone.org 14 September 2012 | Volume 7 | Issue 9 | e44286