Purpose: The aim of the study was to examine associations between speaking fundamental frequency (f[subscript os]), vowel formant frequencies (F), listener perceptions of speaker gender, and vocal femininity-masculinity. Method: An exploratory study was undertaken to examine associations between f[subscript os], F[subscript 1]-F[subscript 3], listener perceptions of speaker gender (nominal scale), and vocal femininity-masculinity (visual analog scale). For 379 speakers of Australian English aged 18-60 years, f[subscript os] mode and F[subscript 1]-F[subscript 3] (12 monophthongs; total of 36 F[subscript s]) were analyzed on a standard reading passage. Seventeen listeners rated speaker gender and vocal femininity-masculinity on randomized audio recordings of these speakers. Results: Model building using principal component analysis suggested the 36 F[subscript s] could be succinctly reduced to seven principal components (PCs). Generalized structural equation modeling (with the seven PCs of F and f[subscript os] as predictors) suggested that only F[subscript 2] and f[subscript os] predicted listener perceptions of speaker gender (male, female, unable to decide). However, listener perceptions of vocal femininity-masculinity behaved differently and were predicted by F[subscript 1], F[subscript 3], and the contrast between monophthongs at the extremities of the F[subscript 1] acoustic vowel space, in addition to F[subscript 2] and f[subscript os]. Furthermore, listeners' perceptions of speaker gender also influenced ratings of vocal femininity-masculinity substantially. Conclusion: Adjusted odds ratios highlighted the substantially larger contribution of F to listener perceptions of speaker gender and vocal femininity-masculinity relative to f[subscript os] than has previously been reported.