VIDEO: What Sounds Do Plants Emit That Are Inaudible to Humans? Scientists' Study

Scientists have recorded ultrasonic sounds that plants emit during water stress or sudden damage. These signals are likely to assist in the formation of ecosystems, and nearby creatures also respond to them.

“When plants are in good condition, they emit less than one sound per hour, but under stress, the sounds increase significantly, sometimes reaching 30 to 50 sounds per hour,” said biologist Lila Hadani.

Researchers recorded the sounds of tomatoes and tobacco grown in greenhouses. The sounds increased when the plants were deprived of water or when their stems were cut.

The sounds can be detected up to five meters away but fall within the 40 to 80 hertz range, which is inaudible to humans. However, insects and small mammals can hear such frequencies.

Most likely, the sounds are generated when the plants' vessels are damaged, creating air bubbles. It is unlikely that these sounds are attempts at communication, but other animals can receive information from them.