This is What it Sound Like When Foxgloves Cry

“Plants that need water or have recently had their stems cut produce up to roughly 35 sounds per hour, the authors found. But well-hydrated and uncut plants are much quieter, making only about one sound per hour. The reason you have probably never heard a thirsty plant make noise is that the sounds are ultrasonic — about 20–100 kilohertz. That means they are so high-pitched that very few humans could hear them.” Stressed Plants ‘Cry’—and Some Animals Can Probably Hear Them. When I was a kid, I was a picky-eating vegetarian who often wondered whether, if you listened closely enough, you could hear lettuce scream when you tore leaves from its head. Now I’m more worried.