Do Plants Make Noises?

News Desk

Islamabad: Researchers in Israel found that plants make a high-frequency clicking sound when placed under stress. The plants made noises when they were cut or when they were thirsty.

According to scientists, the frequency of the sound is too high for human ears but could be heard by insects or mammals.

During a six-year study, the researchers at Tel Aviv University listened to a variety of plants, including tomatoes, grapevines, tobacco, and wheat. Their findings are published in the peer-reviewed journal Cell Press.

The scientists recorded both healthy and stressed plants using microphones. “We recorded the sounds emitted by plants; we used mostly tomato and tobacco, but we also recorded wheat, grapevine, and cacti,” Lead Author Lilach Hadany said.

Lilach reveals that the researchers used various techniques to distress the plants. “We primarily exploited two pressures, which both produce sounds: drying the plant and cutting it with scissors. If we cease watering the plant during dehydration, it begins to make a sound, which peaks around day two,” she said.

The recordings were made in a greenhouse-themed, soundproofed acoustic room.

Following the recording of the plants, the researchers created a machine-learning algorithm to distinguish between healthy, thirsty, and clipped plants. They combined many ultrasonic sound samples over a brief period of time and altered the frequency to make the sounds detectable to human ears. Although they have previously been detected in plants, airborne ultrasonic vibrations are a new discovery, according to Hadany.

The scientists believe further research could reveal more about how plants interact with their environment.

Evolutionary biologist Hadany stated that the fact that we cannot hear plants does not imply that they are quiet to other living things. Plants can be heard by insects like moths or animals like mice and bats. But “an exciting question that is not yet clear” is why plants create sounds, she further stated.

“There are two options: the exciting direction is that it is used for communication, but there is also the option that the sounds are a by-product of physiological processes,” explained the lead author. What’s also not yet clear is whether the sound-emitting plants are hoping to distract predators or attract pollinators, she added.