Social history influences the proportional use of different ultrasonic vocalization (USV) types emitted by pairs of male mice.

(a) Proportional use of 70-kHz plain USVs. (b) Proportional use of 70-kHz jump USVs. (c) Proportional use of 50-kHz plain USVs. (d) Proportional use of 50-kHz jump USVs. Bar heights represent means ± S.E.M; bars with different letters are statistically different (Kruskal-Wallis tests with Bonferroni post-hoc tests, p < 0.05). IND = individually housed male; SOC = socially housed male. See methods for additional details regarding housing history and USV types.