We compared acoustic features and sequencing of four major USV syllable categories [simple (s), down (d), up (u), and multiple (m) pitch jumps; Figure 1D] from wildtype (n = 8) and Foxp2-R552H heterozygous (n = 10) male littermates in four social contexts: with female urine [UF], live female [LF], anesthetized female [AF], or anesthetized male [AM]. The gene discussed is FOXP2; the disease is atrial fibrillation.