Overview
- The peer-reviewed study, published February 23 in Current Biology, shows that a horse’s whinny contains a low tone from vibrating vocal folds and a distinct high-frequency whistle generated in the larynx.
- Endoscopy of live horses revealed vocal-fold vibration alongside laryngeal muscle contractions that narrow the glottis, creating airflow conditions that produce the whistle.
- In excised-larynx trials, the high component shifted upward in helium while the low component stayed constant, confirming a whistle for the high pitch and tissue vibration for the low pitch.
- Researchers report the first strong evidence of an aerodynamic laryngeal whistle in a large mammal and the only known case where such a whistle occurs simultaneously with vocal-fold vibration.
- Scientists propose that the two frequencies may carry different information and note that Przewalski’s horses share the trait, whereas donkeys and zebras appear to lack the high component, leaving functional roles for future testing.