Do men with more masculine voices have better immunocompetence?

The human voice is often considered to be a secondary sexual characteristic that signals underlying information about the immunocompetence of the speaker (i.e. the immunocompetence handicap hypothesis; ICHH). However, no studies have yet shown a relationship between vocal characteristics and biomarkers of immune function or self-reported health. In a sample of 108 men, we examined correlations between masculine vocal characteristics [i.e. relatively low fundamental frequency (F-0), low F-0 variability (F-0-SD), low formant position (P-f), and high vocal tract length (VTL)] in relation to salivary immunoglobulin-A (sIgA; a marker of mucosal immunity), testosterone (T), and well-validated measures of self-reported health status. Results showed that sIgA correlated with masculinized F-0, P-f, and VTL. Self-report health correlated with masculinized P-f and VTL. Anticipated future health correlated negatively with F-0-SD and sick role propensity (less interference of illness in daily life) correlated positively with VTL. Perceived susceptibility to infection correlated with more feminized F-0 and F-0-SD. Our results demonstrated a small relationship between men's vocal characteristics and one putative indicator of mucosal immunity along with self-identified health status. We suggest that more research is warranted to determine whether the masculinity of men's voices may serve as an indicator of their phenotypic quality.