We are all aware that plants are living organisms and have stimulus and response. In a recent study by Tel Aviv University in Israel led by Itzhak Khait, it was found that plants make noise out of pain. These noises are so high that they cannot be heard by human ears. Rather they can be heard by organisms like mice and bats.
As a part of their experiment, they placed microphones capable of detecting ultrasonic frequencies. The microphones were put four inches away from tomato and tobacco plants when they were either not watered or cut through their stems.
They noted noises with frequencies between 20 to 150 kilohertz. These noises are at such high frequencies that only certain organisms like bats, mice could hear it. Through the noise, the team was able to distinguish if they were out of pain or water stress, Smithsonian.com reported.
The research claimed, “We recorded ~65 dBSPL ultrasonic sounds 10 cm from tomato and tobacco plants, implying that these sounds could be detected by some organisms from up to several meters away.”
“We 35 developed machine learning models that were capable of distinguishing between plant sounds and general noises, and identifying the condition of the plants – dry, cut, or intact – based solely on the emitted sounds. Our results suggest that animals, humans, and possibly even other plants could use sounds emitted by a plant to gain information about the plant’s condition.”
A tobacco plant emitted an average of 15 sounds within an hour of being cut and the tomato plant emitted 25 sounds. When stressed by running out of water for up to ten days, the tobacco plant made 11 squeals sound per hour and the tomato plant made 20 squeals per hour.
The scientists came up with one theory about how the plants make noise. As water travels from the plant’s xylem tubes when in pain or stress, the air bubbles burst and make noise because of small vibrations.
The researchers further added that this study can help farmers to protect the plants and save them from insects. They can also make human beings think twice before hurting the plants.