For as long as we’ve been paying attention, plants have been the stoic monks of the natural world. Occasionally, they pull their best yoga move by stretching toward the sunlight. But that’s the most amount of action we’ve seen…so far.

No drama, no noise — just quiet, reliable photosynthesis.

But what if there was a whole other layer of plant life we’ve been unaware of because we’re deaf to it?

Plants may be silent to us, but that doesn’t mean they’re mute.

Ultrasonic whispers

A team of scientists at Tel Aviv University decided to find out if plants could emit sounds when under stress.

Or in other words, do your houseplants passive-aggressively complain when you forget to water them?

The quick answer is yes, just not in a way we humans can hear.

The goal of the research was to see if plants emit sound waves that could tell us when they’re in trouble, potentially revolutionizing how we monitor crops and manage resources.

The researchers took some tomato and tobacco plants, put them in a soundproof box, and then stressed them out — cut their stems and deprived them of water. A bit harsh if you ask me. Using super-sensitive microphones, they recorded ultrasonic sounds between 20–150 kHz — frequencies way beyond what our ears can pick up.

Then, they trained machine learning models to sort through these plant “cries” and determine what kind of stress the plant was under. They also ran the same experiments in a noisy greenhouse full of distractions like wind and maintenance sounds.

So what did they find?

When stressed, the tomato plants emitted about 35 sounds per hour (i.e. number of distinct ultrasonic sound events), and tobacco wasn’t far behind with 11 per hour. Meanwhile, the unstressed control plants? Barely a peep — less than 1 sound per hour.

Each “sound” is like a burst or pulse in the ultrasonic frequency range, like individual squeaks. They’re not continuous tones like the hum of a refrigerator but rather distinct, short pulses. In other words, plants emit 35 detectable bursts of ultrasonic vibrations every hour when they’re under stress.

Another interesting finding is that scientists could distinguish between different stress types with an accuracy of up to 84% in the noisy greenhouse, and machine learning models nailed plant conditions (like drought vs. injury) with 70% accuracy in the acoustic box.

That’s actionable data!

What does this mean?

Tackling water scarcity

Imagine using sound tech to monitor crops remotely, ensuring plants get water before they hit a dehydration panic mode. Smarter irrigation could save up to 50% of water, which is a big deal as climate change makes water scarcity the new norm.

Agriculture uses about 70% of global freshwater, and we waste a ton of it by overwatering. If fields of crops are fitted with mics listening to plants in real-time we could save billions of gallons of water annually. Smart irrigation systems could respond only when the plants actually need it.

No guesswork, no waste.

And this isn’t just about water. Imagine using these plant signals to detect disease early or optimize pesticide use. Less waste, fewer chemicals, healthier crops, healthier planet. That’s a win-win-win.

Plants as dynamic beings

For centuries, we’ve thought of plants as passive, silent organisms. They grow, they photosynthesize, they sit there.

But this study says there’s more to plants than meets the eye. Plants are expressive — they just operate on frequencies we couldn’t hear.

They’re communicating stress, signaling their needs, and maybe even sending out an SOS to neighboring plants. This pushes us to rethink how we interact with the natural world.

Plants become collaborators in survival, not just decoration or food sources.

The future is sonic

We’ve just been too tone-deaf to notice. But now, with a little help from cutting-edge tech and machine learning, we’re finally tuning into the plant kingdom.

Welcome to the era of plant bioacoustics where agriculture is just the tip of the ice.

What else could we do with this insight? Urban environments could have green spaces that “talk” to city planners, optimizing water and energy use. Conservation areas where we could monitor endangered plants could alert us to stress before it’s too late. Even your home garden could get alerts like “Your petunias are whining for water”.

So let’s not manage resources blindly (or deafly) anymore.

Let’s tune to nature’s frequency and work alongside it, not against it.

If you want to learn much more about the relationship between plants and sound, check out my book on Amazon about it!