Plants Under Stress Emit Ultrasonic Clicks Humans Can’t Hear
Researchers recorded stressed tomato and tobacco plants and found they emit airborne ultrasonic clicks not audible to humans. Stressed plants produce roughly 30–50 sounds per hour (healthy plants are mostly silent), with sounds varying by stress type (dehydration vs. cutting). A machine-learning model could distinguish healthy vs stressed plants and identify the stress type and plant species. The exact origin may be cavitation, and it’s unclear if these sounds are deliberate signals or byproducts. Ecologically, other organisms might hear and respond to these signals, and there could be agricultural uses for monitoring crop health and irrigation.
