Like humans, plants also scream and make varying sounds when they are in pain, a new study has claimed.
Called “airborne sounds”, the research, which was published on Thursday in the journal ‘Cell’, notes that plants, when deprived of water or stressed, emit ultrasonic sound waves so that other creatures can hear.
The researchers further noted that the frequency of these noises is too high for humans to detect, but they can be heard by insects, other mammals, and possibly other plants. They further said that the sound of these noises varies according to the mood of the plants.
The research was carried out by a team at Tel Aviv University in Israel.
“We found that plants usually emit sounds when they are under stress and that each plant and each type of stress is associated with a specific identifiable sound,” researchers said in a news release from the university.
“While imperceptible to the human ear, the sounds emitted by plants can probably be heard by various animals, such as bats, mice, and insects.”
In their experiment, the team, led by Lilach Hadany at Tel-Aviv University, placed tobacco and tomato plants in small boxes, and affixed an ultrasonic microphone at 10 centimetres gap.
When stressed, such as inflicting pain or not providing water, the plants made noises, which were picked up only by the microphone.
When the sounds were pitched down and sped up, it sounded “a bit like popcorn — very short clicks,” Hadany said. “It is not singing.”
The sounds detected were in the frequency range between 20 and 250 kilohertz. While human adults can only hear frequencies of up to 16 kilohertz, researchers said.
These recordings were analysed by special AI algorithms that could differentiate between plants and the types of sounds they were emitting.
And the more stressed plants were, the more they screamed.
“Unstressed plants emitted less than one sound per hour, on average. While the stressed plants – both dehydrated and injured – emitted dozens of sounds every hour,” researcher Lilach Hadany said, according to Science Daily.
(With inputs from agencies)
