Can plants hear?

For decades, the idea that plants are receptive to sounds, music, and even human speech has captured the curiosity of scientists and gardening enthusiasts. While some claim that talking to plants or playing music can improve their growth, others consider this a myth with no scientific basis. However, recent research is beginning to reveal that although plants do not “hear” in the conventional sense, they can perceive and react to sound vibrations.

Can plants “hear”?

Although plants lack the hearing organs that animals possess, such as ears, research has shown that plants can detect vibrations in their environment. Sound waves are essentially vibrations that propagate through air, water or soil, and plants, with their specialized cellular structures, are able to perceive these vibrations.

A landmark study published in 2014 by researchers at the University of Missouri found that plants of Arabidopsis thaliana (a close relative of the mustard) could perceive the sound of vibrations of caterpillars chewing on its leaves. When plants “heard” these vibrations, they responded by increasing their production of defensive chemicals to protect themselves from insect attack. This discovery was one of the first solid evidence that plants can perceive sound and react in a meaningful way.

How do plants perceive sound?

Plants do not “listen” in the same way as humans or animals, since they do not have ears or nervous systems. However, sound vibrations can generate physiological responses in them. The key is in the mechanical and molecular structures of plant cells. Vibrations caused by sound can be detected by plants’ mechanoreceptors, cellular structures that respond to physical stimuli, such as movement or pressure.

These vibrations can alter the behavior of cell membranes and trigger biochemical reactions in plants. For example, they can influence the opening and closing of stomata (pores in leaves) or the production of hormones such as abscisic acid, which plays a crucial role in the stress response. This suggests that plants can “sense” their environment in a much more complex way than previously believed.

Does music really affect plant growth?

The question of whether music can influence plant growth has been the focus of several experiments since the mid-20th century. Some gardeners and scientists claim that certain musical genres can stimulate plant development, while others can be harmful. But what does science say?

One of the best-known studies in this area was carried out in 1973 by Dorothy Retallack, author of the book The Sound of Music and Plants. In his experiment, he exposed several plants to different types of music. According to Retallack, plants that were exposed to classical music showed more vigorous growth, while those that listened to hard rock music seemed to wilt. However, although their experiment generated a lot of interest, it has not been consistently replicated with scientific rigor.

On the other hand, a study carried out in South Korea in 2007 showed that music could influence the genetic expression of plants. The researchers discovered that certain musical frequencies promoted the activation of genes related to growth and stress response. However, these results are preliminary and there is no scientific consensus on whether music has a universal and reproducible impact on plant growth.

Does talking to plants help them grow?

Another popular belief is that talking to plants can help them grow better. The Royal Horticultural Society, in a 2009 study, attempted to investigate this claim. During a month-long experiment, the researchers recorded different people reading texts and then exposed several tomato plants to these recordings. The results showed that plants that “heard” human voices grew slightly faster than plants that did not, with a notable difference in plants that heard female voices.

Although this study attracted attention, scientists believe that the reason behind this growth has less to do with the human voice itself, but rather with the vibrations produced by sound. The vibrations could be stimulating the movement of fluids within plants or affecting cellular activity in a similar way to sound waves from other sources.

What kind of sounds do plants prefer?

Some experiments suggest that plants may be more receptive to low-frequency sounds, such as those generated by classical music or birdsong, compared to high-frequency or noisy sounds, such as rock music or urban noise. . A study conducted in China in 2014 found that rice plants exposed to low-frequency vibrations showed an increase in the production of certain proteins important for their growth, while high-frequency vibrations showed no positive effects.

Demystifying beliefs

Although there is some evidence that plants may respond to vibrations and sound in ways that influence their growth, it is important to clarify that there is no definitive evidence that music or human speech has a significant or consistent impact on their development. What is clear is that plants are much more complex organisms than previously thought, and their ability to perceive their environment includes the detection of mechanical and vibrational stimuli.