According to researchers from Tel Aviv University, plants emit unique sounds that are inaudible to humans but detectable by animals.
These sounds are similar to click-like noises and vary depending on the species and the cause of their growth stress. Ultrasonic microphones recorded the sounds emitted by tomatoes, grape vines, tobacco, wheat, corn, cactus, and henbit in a soundproofed chamber. The team discovered that while unstressed plants produce less than one sound per hour, stressed plants emit dozens of sounds every hour.
Here’s one of the sounds they were able to record.
The researchers suggest that the sounds contain information about water scarcity or injury, which can be useful to growers with the right tools, such as sensors that tell when plants need watering.
The study addressed a long-standing debate in the scientific community regarding whether the vibrations that plant vibrometers pick up from plants could become airborne sound waves. Further research will explore other questions, including the mechanism behind plant sounds, how moths react to the sounds, and whether other plants hear these sounds.