Do Plants Make Noise? The Science of Plant Sounds

Plants do produce sounds, and stressed plants produce a lot of them. A landmark 2023 study published in Cell recorded drought-stressed tomato plants emitting roughly 35 ultrasonic clicks per hour, while well-watered control plants barely managed one. These sounds sit in the ultrasonic range, far above what human ears can detect, but they are airborne, recordable from a distance, and carry enough information that machine learning algorithms can tell a thirsty plant from a cut one. The science of plant acoustics is young, but it is already reshaping how biologists think about organisms that were long dismissed as silent and passive.

What These Sounds Actually Are

The sounds plants emit are short, click-like bursts of ultrasonic energy. When researchers at Tel Aviv University placed tomato and tobacco plants inside acoustic chambers and recorded them with specialized microphones, they captured sounds with peak frequencies around 50 to 58 kHz, well above the roughly 20 kHz ceiling of human hearing. The intensity was about 62 to 66 decibels measured at 10 centimeters from the plant, which is comparable to normal conversation volume if you could hear it.¹ That’s loud enough, in principle, to be detected by other organisms several meters away.

The critical finding was the difference between stressed and unstressed plants. Drought-stressed tomato plants averaged about 35 sounds per hour, and cut tomato plants averaged about 25 per hour. Tobacco plants showed similar patterns. Control plants in all groups emitted fewer than one sound per hour.¹ So it’s not that healthy plants are chatty and stressed plants chatter louder. The quiet baseline is essentially silence, and stress flips a switch.

Why Stressed Plants Are Louder

The leading explanation involves a process called cavitation inside the plant’s water-transport system. Plants pull water from their roots to their leaves through microscopic tubes called xylem vessels. When a plant dries out, tension builds in these water columns. Eventually, the water column snaps and air bubbles form, producing a tiny burst of acoustic energy. This process has been studied for years using contact sensors pressed directly against stems, which can detect the vibrations created by these events.²

What the 2023 study added was evidence that these events are not just internal vibrations but produce airborne sound waves that travel through the air. Several observations supported cavitation as the mechanism. Different plant species have different xylem diameters, and the frequencies of their emitted sounds tracked with those diameters: wider tubes produced lower-frequency sounds, which is consistent with how resonance works in tubes of different sizes. The acoustic profiles of drying and cutting also differed in ways that matched the underlying physics. Drying is gradual, so air enters the xylem slowly and at reduced pressure. Cutting is sudden and exposes many tubes to air simultaneously, producing a different acoustic signature.¹

That said, cavitation probably isn’t the whole story. The researchers noted it may be responsible for “at least part” of the sounds they recorded. Other mechanical processes in the plant could contribute, and teasing apart those contributions is an active area of research.

You Can Tell What’s Wrong by Listening

One of the more striking findings from the Tel Aviv work is that plant sounds aren’t just noise. They carry information that can be decoded. When the researchers trained machine learning classifiers on the recorded sounds, the algorithms could distinguish between drought-stressed and cut plants of the same species with about 70% accuracy, and they could tell plant sounds from background electronic noise with over 98% accuracy.¹

That 70% figure might sound modest, but consider what it implies: the acoustic clicks from a plant losing water and a plant that has been physically damaged are different enough that a computer can tell them apart just from the sound. The algorithms also successfully distinguished between tomato and tobacco plants undergoing the same stress. If these patterns hold across more species and stress types, the practical potential is real. Farmers or greenhouse operators could, in theory, deploy ultrasonic microphones to monitor crops for drought stress before visible wilting occurs, getting an early warning that irrigation is needed.

Researchers have also been working on making this kind of monitoring more accessible. A 2024 paper proposed a cost-effective setup for recording plant ultrasonic emissions using just a single ultrasound microphone, a laptop, and open-source software, noting that standardized methods for this work haven’t been established yet.³ The field is still figuring out its tools.

Which Plants Have Been Tested

Most of the detailed acoustic data comes from tomato and tobacco plants, which served as the primary subjects in the 2023 study. But the researchers also surveyed additional species and successfully recorded sounds from wheat, corn, grapevine (Cabernet Sauvignon), pincushion cactus, and henbit. They did not detect sounds from the woody parts of almond and grapevine, which suggests that the phenomenon may depend on the tissue type and anatomy of the plant.¹

The researchers concluded that they expect many plants emit sounds, but the diversity of those sounds across the plant kingdom remains largely unexplored. We’re looking at early days for a phenomenon that probably turns out to be widespread, at least among herbaceous plants with well-developed water-transport systems. Whether woody trees produce similar airborne sounds from their trunks is less clear, and the negative results with almond wood hint that the answer might be more complex for large perennials.

Plants Can Hear, Too

The idea that plants respond to sound is actually older and in some ways better established than the discovery that they produce it. Plants lack ears and nervous systems, but they have mechanosensitive structures that can detect vibrations. At the molecular level, sound exposure triggers calcium ion surges, potassium fluxes, and an increase in reactive oxygen species through channels that respond to mechanical pressure.⁴ These are some of the same signaling cascades that plants use to respond to touch, wind, and gravity, suggesting that sound perception piggybacks on existing mechanosensory hardware rather than requiring a dedicated hearing organ.

A 2026 review catalogued the strongest mechanistic candidates for how plants sense sound: deformation of cell membranes, activation of mechanosensitive ion channels, calcium influx, reactive oxygen species signaling, changes in gene expression, and shifts in plant hormones.⁵ The picture that emerges is not a single “ear” but a whole-cell mechanical sensitivity that translates sound vibrations into chemical and genetic responses.

Flowers That Sweeten Their Nectar When They Hear Bees

One of the most vivid demonstrations of plant sound perception involves flowers and pollinators. Evening primrose (Oenothera drummondii) flowers exposed to the playback of bee wing-beat sounds or synthetic sounds at similar low frequencies produced nectar with about 20% higher sugar concentration within minutes, compared to flowers in silence or flowers exposed to high-frequency sounds.⁶ The volume of nectar didn’t change, ruling out the possibility that the flowers were simply losing water and concentrating existing sugar. The flowers genuinely sweetened their offering in response to the sound of an approaching pollinator.

For a while, this remained a single-species result, which naturally raised questions about whether it was a quirk of one plant or a broader phenomenon. A more recent preprint tested the same idea in two additional species, Rhododendron and henbit, and found roughly a 10% increase in nectar sugar concentration in response to bee-buzzing playback and synthetic sounds at bee-like frequencies. Higher-frequency sounds and silence produced no such response.⁷ The effect seems real and may be widespread among bee-pollinated plants, though the field still needs more species tested to be confident about generality.

The evolutionary logic is straightforward: a flower that can detect an incoming pollinator and sweeten its nectar right before the bee arrives makes itself more attractive and more likely to achieve successful pollination. It’s a remarkably sophisticated response from an organism that can’t move or see.

Defending Against Herbivores by Feeling Them Chew

Sound perception in plants isn’t limited to friendly encounters with pollinators. Plants can also detect the vibrations of herbivores feeding on them and mount defensive responses. In one well-known experiment, Arabidopsis plants that had been pre-exposed to the vibrations caused by caterpillar chewing produced higher levels of chemical defenses, specifically glucosinolates and anthocyanins, when caterpillars subsequently fed on them. Plants exposed to silence or other vibrations like wind didn’t show the same priming.⁸

Tobacco plants showed a parallel response: when exposed to vibrations mimicking caterpillar feeding, their nicotine content more than doubled compared to controls.⁹ Nicotine is a potent insect deterrent, so this represents a plant ramping up its chemical arsenal in direct response to the sounds and vibrations of being eaten. The plant can’t run, but it can prepare itself to be less palatable, and it does so faster and more aggressively when it’s been acoustically forewarned.

Roots That Grow Toward the Sound of Water

One of the more surprising findings in plant acoustics involves roots. Pea plant roots were shown to locate a water source by sensing vibrations generated by water moving through pipes, even when there was no actual moisture in the surrounding soil for the roots to follow. The roots grew toward the sound of water rather than in a random direction.¹⁰

Arabidopsis roots displayed something similar when exposed to 200 Hz sound waves over two weeks, growing toward the sound source.¹¹ This directional growth in response to sound, sometimes called phonotropism, adds acoustic cues to the already impressive list of environmental signals that roots navigate by, which includes gravity, moisture gradients, and chemical signals from other organisms. For a root system growing through soil where water distribution is patchy and unpredictable, using the sound of flowing water as a guide would be a significant advantage.

The underground acoustic environment is richer than you might expect. Researchers have placed acoustic sensors in soil columns and recorded distinct emissions from growing plant roots and burrowing earthworms. Root growth produced acoustic events several orders of magnitude more numerous than those from bare soil under the same conditions, and the cumulative acoustic events correlated with root growth and earthworm burrow length.¹² The soil beneath our feet is acoustically active in ways that we’re only beginning to document.

Who Else Is Listening to Plants

If stressed plants emit ultrasonic sounds that travel through the air, an obvious question is whether any animals have figured this out and are using these sounds as information. A 2024 preprint offered intriguing evidence that female moths incorporate plant acoustic emissions into their decisions about where to lay eggs. In the absence of actual plants, the moths preferred to lay eggs near speakers playing back sounds recorded from dehydrating plants. But when real plants were present, the preference flipped, and the moths chose silent (well-watered) plants, which aligns with their known preference for hydrated host plants. Deafening the moths eliminated the preference entirely, confirming the choice was based on hearing.¹³

This result is still a preprint and awaits peer review, but the experimental design was clever. The fact that moths reversed their preference depending on whether real plants were also available suggests a nuanced behavior rather than a simple attraction to sound. In nature, a moth hearing plant stress sounds might use them to assess the hydration status of potential host plants from a distance before approaching to investigate further. Insects like moths and certain beetles have hearing capabilities that extend into the ultrasonic range, which means they already possess the hardware needed to detect plant emissions.

Can Plants Warn Each Other With Sound

Plants are already known to communicate chemically, releasing volatile organic compounds that neighboring plants detect and respond to by priming their own defenses. Acoustic communication between plants is a more speculative idea, but there’s suggestive evidence. When well-watered chili pepper plants were exposed to vibrational recordings taken from drought-stressed chili peppers, the well-watered plants showed gene expression changes characteristic of drought response, as though they were preparing for a dry spell that hadn’t arrived yet.¹⁴

This is the kind of result that gets researchers excited about agricultural applications. If playing stress-associated sounds to crops could prime them against drought or other challenges, it might offer a chemical-free way to boost resilience. But the research is still early, and there’s a big difference between showing that a plant responds to vibrations in a controlled lab setting and demonstrating that this happens meaningfully in a noisy, wind-swept field. The distances involved, the competing sound sources, and the question of whether plants produce enough acoustic energy for other plants to detect all remain open.

What Traffic Noise Does to Roadside Plants

If plants are genuinely sensitive to acoustic vibrations, then the noise pollution generated by human activity could affect them. Research on two urban plant species exposed to traffic noise found that it caused significant decreases in growth, along with signs of oxidative stress: increased levels of damaging reactive molecules, elevated activity of antioxidant enzymes trying to compensate, reduced levels of growth-promoting hormones, and increased levels of stress hormones like abscisic acid and jasmonic acid.¹⁵

Traffic noise is a complex stimulus that includes vibrations across a wide frequency range, so isolating the acoustic component from other confounders like air pollution along busy roads isn’t trivial. Still, the hormonal and oxidative changes mirror what you’d see in a plant experiencing genuine physiological stress, not just a cosmetic slowdown. This raises uncomfortable questions about roadside vegetation, urban gardens, and agricultural land near highways. We’ve spent decades studying how noise affects birds, whales, and other animals. The possibility that plants are also affected adds another dimension to the noise pollution problem.

Why This Took So Long to Discover

Plants were considered passive, static organisms for most of the history of biology, and that framing shaped what questions researchers thought to ask.¹⁶ There were also practical barriers. The ultrasonic emissions from plants are inaudible without specialized equipment, and the frequencies involved (40 to 80 kHz and higher) require microphones designed for bat research or industrial testing, not standard audio gear. Earlier work with contact sensors had detected cavitation vibrations inside stems, but the conceptual leap that these events could produce airborne sounds detectable from a distance took longer to test.

There’s also an unfortunate baggage problem. The idea that plants respond to sound has been associated for decades with pseudoscientific claims about talking to your houseplants or playing them classical music to help them grow. Those popular culture associations made serious researchers wary of the topic. What’s different about the current wave of research is methodological rigor: acoustic chambers, controlled treatments, replicated experiments, machine learning validation, and molecular-level evidence of the signaling pathways involved. The field has managed to separate the real phenomenon from the folk mythology, though some skepticism persists among biologists who haven’t followed the recent literature closely.

What We Cannot Hear and What Machines Might

For your houseplants, the practical takeaway is modest. You cannot hear them, and they are not screaming in pain when you forget to water them, at least not in any way that implies conscious experience. What they are doing is generating physical acoustic events as a byproduct of water stress, and those events happen to carry information about the plant’s condition. The plants are no more “talking” than a cracking ice sheet is complaining about the cold. But the analogy to ice isn’t quite right either, because the biological context is richer: flowers seem to have evolved responses to specific sound frequencies, roots navigate toward water sounds, and moths may be eavesdropping on plant stress. These are ecological interactions, not just physics.

The most promising near-term application is precision agriculture. Ultrasonic monitoring could, in principle, detect crop water stress days before visible wilting, allowing more targeted irrigation. Given that agriculture accounts for roughly 70% of global freshwater use, even small improvements in irrigation timing matter enormously. The technology isn’t ready for commercial deployment yet, and distinguishing plant sounds from environmental noise in a real field is a much harder problem than doing so in an acoustic chamber. But the foundations are being laid, and as ultrasonic sensors become cheaper and machine learning models improve, acoustic crop monitoring could join the toolkit alongside satellite imaging and soil moisture sensors.