A new study has found that plants emit sounds when thirsty or under stress, which are not audible to humans, according to CNN. The study reveals that these plant sounds occur at a volume similar to human speech but at high frequencies beyond the range of human hearing. Co-researcher Lilach Hadany stated, "We analyzed an old scientific debate and proved that plants produce sounds."
The researchers placed tobacco and tomato plants in soundproof boxes equipped with ultrasonic microphones that recorded frequencies between 20 and 250 kilohertz. The upper limit of frequency that an adult human ear can detect is about 16 kilohertz. The team found that plants produce sounds at frequencies of 40 to 80 kilohertz, and when amplified and translated into a frequency audible to humans, the sounds resembled the noise of corn when it is popped. Previous studies have shown that plants emit vibrations, but it was unclear whether these vibrations became sound waves transmitted through the air.
