Figure 3. Validation of USV technique and comparison to manual classification standard.

(a) Exemplar USVs from a mouse on the C57BL/6J background at P7. (Scale bar = 200 msec.) (b) A dendrogram generated following spectral similarity scoring of USVs where calls are represented as leaves and branch points indicate the difference in weighted correlation between leaves. Beneath the branches, clusters automatically determined by the tree-trimming algorithm are denoted by unique color bands and illustrated by representatives at descending percentiles following correlation of each cluster member to the cluster eigencall. The Pearson’s rho for the correlation between each syllable and the eigencall are displayed in white. (c) Bar plots indicate the count of each call type when the classification is performed manually (white) or using VoICE (black). Pie charts, right, illustrate the percentage distribution of each call type for the same animal’s repertoire as determined by manual sorting or using VoICE. (Scale bar = 10 msec.)