Why Cats Purr at 25 Hz: Vocal Fold Pads and the Physics of Self-Sustained Oscillation
For decades, the mechanism of purring was disputed. A 2023 paper in Current Biology showed that cat larynges purr without any neural input: airflow alone drives a self-sustained oscillation. The secret is connective tissue pads embedded in the vocal folds that increase effective mass and lower the resonant frequency to 25–30 Hz — the same range used clinically for bone- density stimulation and fracture healing under Wolff’s law.