For the first time in the world, researchers from Tel Aviv University recorded and analyzed sounds clearly emitted by plants. The clicks, similar to the popping of popcorn, are emitted at a volume similar to that of human speech, but at high frequencies, beyond the range of hearing of the human ear. The sounds of plants are informative: they are emitted mainly when the plant is under stress, and they contain information about its state.
The sounds that plants make when they are under stress vary, and each plant and each type of stress is associated with a specific identifiable sound. Although imperceptible to the human ear, the sounds emitted by plants can probably be heard by various animals, such as bats, mice, and insects.