The Secret Sounds of Stressed Plants Unveiled by Scientists

Plants emit ultrasonic sound waves when they are stressed or deprived of water, according to a new study by researchers at Tel Aviv University in Israel. 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. The sound of these noises varies according to the mood of the plants, and the more stressed plants were, the more they emitted sounds. The research was carried out by placing tobacco and tomato plants in small boxes and affixing an ultrasonic microphone to detect the sounds.