Plants grow silently. Absence of vocal cords prevents them from singing, crying or conversing with neighbours like animals. With that said though, plants do make sounds to which animals listen and we humans can hear according to a recent study.
Eavesdropping moths
In 2023, researchers at Tel Aviv University in Israel contradicted conventional beliefs about plants with their groundbreaking findings published in a science journal. Their study proved tomato and tobacco plants emit ultrasonic signals (at frequencies of 20 to 100kHz) in response to stress such as dehydration or injury etc. The airborne sounds differ depending on plant species, e.g. tomato or tobacco, and type of stress, e.g. dehydration or cuts.
In their later study, Egyptian Cotton Leafworm (Spodoptera littoralis), a common crop pest, was revealed to prefer laying eggs on quiet plants over ones emitting ultrasonic distress sounds. Listening to plants helps female moths choose healthy ones.
%20Tiziana%20Dinolfo.jpeg)
But scientists tell us not to get all worked up about sounds made by plants as plant talk. The sounds are hypothesised to come from cavitation - the formation and busting of air bubbles in the xylem or mechanical vibrations caused by charged cell membranes and walls. There is no evidence to suggest the plant has control over the production of sounds or is making an attempt at communication.
Whistling plants
The same theory of plant acoustics applies in the desert. Cacti and dried grass whistle and groan as the wind sweeps across the open desert. The "wind-whistling" phenomenon arises from the intricate interaction between wind and the contours of objects. When air flows past through a small hole, trough or hollow structure of a plant, it creates a vortex induced vibration. The hollow stem or any internal cavity of a plant is comparable to a music instrument's resonance chamber, which amplifies sound waves and allows humans to hear.
%20JA%20Fields.jpg)
Pulsing trees
You do not have to travel to a desert to hear plants. Trees are nearby. Have you played a sensory game to get to know and feel a tree using your senses of sight, hearing, smell and touch? Your can pick up a tree's "heartbeat" with your ears.
Listen to a tree with a stethoscope or simply put your ears on its trunk. It makes "long long" sounds like a train chugging along. The sound comes from water flowing through its xylem. If you listen to tall trees with thin bark on a sunny day, you will hear louder "heartbeats".
