The Researchers Who Proved Plants Scream

The plants in the greenhouse were stressed. They had been left without water for several days, or had their stems cut, or had been left alone. And they were, as it turned out, making noise about it.

Not noise you can hear. The sounds registered between 20 and 100 kilohertz — well above the range of human perception. But they were real sounds, emitted into the air, measurable with the right equipment, and distinct enough in pattern that a machine learning model could tell the difference between a thirsty tomato plant and one that had just been cut.