Sound has always been considered a fundamental part of life on Earth. Although most known species of animals are known to communicate with each other via sounds, the association of plants with sound production or recognition has hardly been talked about. However, mounting scientific evidence does appear to suggest that plants could be capable of recognizing and responding to sounds in nature and to sounds produced by human beings. If this is true, we might have to think twice before cutting down a tree in the presence of another one and also be able to grow healthier plants with the aid of soulful music.
Observations and Evidence
Ancient folklore tales originating from various parts of the world have always mentioned how plants listen to humans when they talk. Several observations have also been made my the common man over the years regarding plants and their listening capabilities. Many people believe that their plants listen to the music played by them, exhibiting faster growth when music is played for a sustained period of time. Plants have also been observed to thrive better when soft, classical music is played to them that when loud rock music is played. A section of scientists believe that these observations do not always mean that plants listen to music. It could be that the plant-keepers who take time out to play music for their plant might also be taking exceptionally good care of their plant, triggering its fast growth and healthy condition. However, there are also quite a few other types of experiments that hint at the fact that plans might listen to sounds. For example, audible sound has been found to alter growth hormone levels in the chrysanthemum plants and the roots of maize seedlings have been observed to bend in the direction of sounds with specific frequencies. In a highly interesting experiment conducted by scientists in 2014, Thale cress plants (pictured) exposed to the sound of chewing caterpillars, were found to release more defensive chemicals on a subsequent encounter with these insects. All these experiments manages to put some weight on the idea of plants listening to human voices or music.
Biological Mechanisms Involved
As of yet, there is no conclusive proof to describe that plants respond to sound. However, from the evidences gathered, some scientists have proposed ways by which these plants might hear and react to sound produced by other living creatures or inanimate objects. Plants are not known to posses any sensory organs of any kind. How then could they receive sounds and react to it? Some scientists explain that plants could do this by receiving sound sensations in the form of touch sensations similar to the way our hearth thumps when we hear a stereo playing at full blast. Just like plants respond to winds, perceiving it as a sensation of touch, plants could also respond to the sound which travels in waveform. When it comes to plants talking themselves, several mechanisms have been suggested by scientists like the use of scents or volatile compounds as a method to communicate with the neighboring plants. Plants have also been thought to produce sounds in frequencies that cannot be perceived by the human ear.
If it is proved that plants do indeed listen and respond to sounds of different types, then it would definitely find huge practical applications in cultivation, forestry and other related programs. There are reports that researchers in China are already growing plants with higher yield by broadcasting sound waves of certain frequencies. There is also some evidence that acoustic vibrations manage to modify plant metabolism. In the future, plant yields and growth rate could be significantly modified with the help of sound waves of varying frequencies. Healthier plants could also be developed with the help of music that the plants love.
There is still an immense research scope to be delved into in the field of plant communication. There is a need to understand how sound vibrations are perceived by plants, if, in fact, they are perceived at all. Furthermore, the responses generated within plants to such vibrations, and whether such responses have meaningful effects on the plant itself, or on other plants in their vicinity, are also areas in need of continued study.