Rapid effects of estrogens and androgens on temporal and spectral features in ultrasonic vocalizations

- Males exhibit a surge in testosterone (T) after interacting with a female across a wire mesh.
- A single sc injection of steroids can change acoustic properties of USV.
- In 30 m, T decreased call duration and frequency over time.
- In 15 m, 17-β estradiol decreased call duration and frequency over time.
- In 30 m, dihydrotestosterone increased the mean number of frequency jumps in multi-note calls.