Take care of your plants! They may "shout " if you treat them badly.
Plants can make sounds when they are stressed, according to a recent study. "Plants use sound to communicate with animals all the time, so it would be very inconvenient for plants not to use sound at all. " Lilach Hadany, co-author (合著者) of the study, told Science Focus.
With this in mind, the research team started by recording plants' sounds. They put sweet-pepper and tomato plants in soundproof boxes to shut off the noise in the environment. Several ultrasonic microphones (超声波麦克风) were then put near the plants, which can record between 20 and 250 kilohertz (千赫兹). A human adult's ear can hear about 16 kilohertz. There were three groups of plants: One group wasn't watered for five days, another group had some parts cut off and the last group was untouched. The microphones caught sounds from 40 to 80 kilohertz from the first two groups. The sound, which was similar to the noise of popcorn popping grew louder and louder during the five days of water stress. They then began to become weaker and weaker as the plants dried out. A stressed plan produced the popping sound around 30 to 50 times per hour, while the untouched group only produced around once per hour, according to the study.
