According to recordings produced for a recent study, plants generate popping noises that are imperceptible to the human ear. They also create more noise when stressed or thirsty.
The discovery challenges what most botanists believed to be true about the plant kingdom, which had previously been regarded as relatively silent, and shows that the environment we live in is a cacophony of plant noises, according to study coauthor Lilach Hadany.
She claimed that she had never believed that plants made any noise at all.
Professor Hadany of the School of Plant Sciences and Food Security and director of the George S. Wise Faculty of Life Sciences at Tel Aviv University remarked, “There are so many organisms that respond to sound, I thought there was no good reason for plants to be deaf and mute.”
When Hadany recorded the first plant in her lab six years ago, she utilized an ultrasonic microphone, but she was unable to rule out the chance that the sound she heard was being created by someone else in the area.
Plants vibrated, but it was unclear if these vibrations could be converted into sound waves that could move through the air. In order to ascertain whether plants were indeed creating sounds, Hadany and her colleagues bought soundproofed acoustic enclosures.
Eavesdropping on Plants
In the boxes, which were outfitted with ultrasonic microphones that record at frequencies between 20 and 250 kilohertz, the researchers planted tomato and tobacco plants. A normal adult’s ear can hear frequencies up to roughly 16 kilohertz. Some of the plants had cut stems or hadn’t received water in five days, while others were unaltered.
The scientists found that the plants make sounds between the range of 40 and 80 kilohertz, which, when reduced and converted into a frequency that people can perceive, resemble the popping of popcorn or bubble wrap.
Although the researchers are unsure of how the sounds are produced, they believe cavitation, a process in which an air bubble in the plant’s water column collapses under some kind of pressure, produces a click or pop.
But don’t worry—the vase of cut flowers in your arrangement isn’t wailing in agony at you. There is no proof that the plants’ noise is deliberate or a means of communication.
Unstressed plants produced just one of these popping or clicking sounds each hour, but stressed plants produced between 30 and 50 of them per hour at what appeared to be random intervals. Tomatoes are incredibly calm when they are not under any stress, according to Hadany.