Do Plants Make Sounds? What the Research Actually Shows

What the 2023 Tel Aviv study actually found

Itzhak Khait, Lilach Hadany and colleagues recorded ultrasonic emissions from tomato (Solanum lycopersicum) and tobacco (Nicotiana tabacum) plants in a soundproofed lab and a greenhouse. They used standard ultrasonic microphones tuned to 20–250 kHz — well above the human hearing ceiling at 20 kHz — and applied two stressors: drought and stem cutting.

The headline result: drought-stressed plants emitted roughly 35 clicks per hour, freshly cut plants around 25 clicks per hour, and unstressed control plants under 1 click per hour. The team also trained a machine-learning classifier on the recordings and showed it could distinguish 'drought-stressed' from 'cut' from 'control' plants from the click patterns alone with above-chance accuracy. The paper was published in Cell on 30 March 2023, one of the most rigorous venues in life sciences, after extensive peer review.

What the study does not show: that the sounds are intentional, that plants are 'in pain', or that the clicks contain information plants use to communicate with each other. The authors are careful in the paper — they describe the clicks as 'airborne and informative', meaning the signals do carry information about plant state, but stop short of claiming any communicative purpose. The clicks may simply be acoustic byproducts of stress that other organisms (insects, mammals) have potentially evolved to listen for.

The likely mechanism: cavitation in the xylem

Plants don't have lungs, vocal cords, or any organ designed to produce sound. The current best explanation for the clicks is cavitation — the formation and collapse of air bubbles inside the xylem, the woody tissue that conducts water from roots to leaves. Under normal conditions, water moves up the xylem under tension, pulled by transpiration from the leaves. When the plant is drought-stressed, that tension increases until water columns in individual xylem vessels snap, forming a vapor bubble. The collapse of these bubbles releases mechanical energy as a brief acoustic pulse.

Cavitation has been studied in plants for decades using contact sensors pressed against stems, where it shows the same characteristic pattern: more clicks under drought stress, fewer when well-watered. The novelty of the 2023 paper is that the same cavitation events are loud enough to be detected through air at meaningful distances, not just through direct contact with the plant. That changes the implications: anything in the same room with hearing into the 20–100 kHz range — moths, mice, bats, some insects — could in principle pick up the signal.

Cutting a stem produces a similar acoustic signature, probably for the same physical reason: severing the water column releases the tension stored in it, and the resulting wave produces clicks as it propagates. This is mechanics, not vocalisation, and it does not require any plant 'awareness' to occur.

What the science establishes vs what the headlines added

Several headlines from 2023 framed the study as 'plants scream when you cut them' or 'plants cry out under stress'. Both phrasings are wrong in specific ways worth naming.

• ·The clicks are not screams. A scream is a deliberate vocal output produced for communication. Cavitation clicks are mechanical byproducts of water-column failure. The plant has no mechanism to choose to produce them.
• ·The clicks are not in the audible range. They are 20–100 kHz, above the human hearing ceiling. You will never hear a stressed plant unless you record it with ultrasonic equipment and pitch-shift the audio downward.
• ·The clicks are not pain. Plants don't have nervous systems, nociceptors, or a brain to integrate a pain signal. Cavitation tells you something is mechanically wrong with water transport — that's it.
• ·The clicks are not (yet) shown to be communicative. The study showed plants produce them; it didn't show plants or other organisms respond to them in any specific way. That would be a separate experiment.
• ·The clicks are real, useful, and interesting. Strip the headlines and the underlying finding is genuinely novel — a previously-unknown acoustic channel out of plants, detectable in air, and informative about plant state.

Earlier work this finding sits on top of

The Tel Aviv paper is the most prominent, but it is part of a longer thread of plant bioacoustics research that has been building for decades. A short tour of the most credible earlier findings:

• ·Mimosa pudica — the 'sensitive plant' folds its leaves on touch within 1–2 seconds. Documented since the 17th century. Mechanism: a turgor-pressure cascade in the pulvinus joints, not active sensing.
• ·Appel & Cocroft (2014) — Arabidopsis plants exposed to recorded vibrations of caterpillar chewing increased their production of glucosinolate defenses, suggesting plants can detect and respond to vibrational input.
• ·Khait et al. (2019) — earlier preprint version of the 2023 finding, distributed before peer review.
• ·Veits et al. (2019) — Israeli group showed evening primrose (Oenothera drummondii) flowers vibrate in response to bee buzz frequencies and increase sugar concentration in nectar within 3 minutes — a possible pollination-attraction mechanism.
• ·Pappas et al. (1969) and successors — early acoustic-emission studies on stems using contact transducers; established the link between drought stress and cavitation clicks.
• ·Hadany & Hadany (2020) review — published a theoretical framework for plant 'hearing' and 'sound production' as evolutionary signals before the 2023 experimental confirmation.

What this does not mean for your houseplant

A reasonable next question for any houseplant owner is: should I do anything differently? Almost certainly not. A few takes worth keeping in mind:

• ·Talking to plants is still mostly placebo. Human voices are 80–250 Hz, deep in the audible range and very far from where plants seem to detect anything mechanically. Talking to a plant might prompt you to inspect it more often, but the sound itself is unlikely to do anything.
• ·Music for plants is mostly unevidenced. A handful of studies show small effects of certain frequencies (often vibrational rather than acoustic) on growth, but nothing rigorous on 'plays Mozart, grows better'.
• ·Stressed plants tell you visually first. Drooping, yellow leaves, crispy tips, and smelly soil all appear before any cavitation signature would matter to a home grower. The acoustic signal is interesting science, not a practical diagnostic.
• ·No, your other plants don't hear when one is suffering. There's no evidence that ultrasonic clicks from one plant produce any specific response in neighbouring plants. The 'forest is talking' story is mostly about mycorrhizal networks underground, not about acoustic signalling above ground.
• ·Plant ID apps don't use sound. They use leaf and growth-form image recognition. See picturethis vs plantnet vs google lens for the visual-recognition state of the art.

Open questions the research has not yet answered

The 2023 study opened more questions than it closed, which is what a good paper does. Several lines of follow-up research are now under way in plant-biology labs around the world.

• ·Do other organisms respond? Moths, bats, and some rodents hear into the 20–100 kHz range. Whether any of them use plant clicks for behaviour — host selection, danger detection, pollination — is an open empirical question.
• ·Do other species emit similar clicks? The original study covered tomato and tobacco. Cactus, succulent, and xerophyte clicks might be louder (more cavitation under desert tensions) or quieter (different xylem architecture).
• ·Are clicks plant-specific or stress-specific? A drought-stressed maple may sound different from a drought-stressed grass in ways that could carry species-level information, in principle.
• ·Is there a fungal connection? Some mycorrhizal fungi might have evolved to detect plant cavitation acoustically, the way some insects detect prey by listening — speculative, but tractable to test.
• ·Could acoustic monitoring become a horticultural tool? Greenhouse growers monitoring ultrasonic emissions as an early-warning system for drought stress is plausible enough that several groups are prototyping it.

What you can take from the science right now

Three plain-language conclusions hold up well after a year and a half of follow-up commentary. They are useful background for any conversation about 'plant sentience' that gets pulled into the news cycle.

First: plants do produce airborne ultrasonic sounds, primarily under drought or cutting stress, and these sounds are detectable with the right equipment. That is now an established empirical fact. Second: the most likely mechanism is cavitation in the xylem, a passive physical process, not active vocalisation. Third: the sounds carry information about plant state, but there is no evidence yet that they carry messages between plants or are produced for any communicative purpose. Anyone making stronger claims is going beyond what the data currently shows.

If you find this research interesting and want to follow it as it develops, the best entry points are the original Cell paper (open access via the link below), the Hadany lab's website at Tel Aviv University, and the broader plant bioacoustics literature on Google Scholar. Almost everything else is downstream commentary on the same primary findings.