New experiments with rice suggest that the acoustic vibrations of falling droplets can jolt dormant seeds into growth, offering the first direct evidence that plants can sense natural sound.
Rice and related seed types can sense the sound of rain impacting the soil or water surface above them and respond by accelerating germination at depths where impulsive rain sound is sufficiently intense to intermittently shake statoliths from contact with cell membrane receptors and trigger gravitropic growth mechanisms.
Plants are surprisingly perceptive. To help them survive, plants have evolved to sense and respond to stimuli in their surroundings.
Some plants snap shut when touched, while others curl inward when exposed to toxic smells.
And of course, most plants respond to light, reaching toward the sun to help them grow.
Plants can also sense gravity. A plant’s roots grow down, while its shoots push up against gravity’s pull.
One way that plants sense and respond to gravity is through their statoliths.
Statoliths are denser than a cell’s cytoplasm and can drift and sink through the cell, like a bit of sand in a jar of water.
When a statolith finally settles to the bottom, its resting place on the cell’s membrane is a reflection of gravity’s direction and a signal for where a seed’s root or shoot should grow.
If the statolith is dislodged, scientists have found that this can also trigger the seed to grow more.
“What our study is saying is that seeds can sense sound in ways that can help them survive,” said MIT Professor Nicholas Makris.
“The energy of the rain sound is enough to accelerate a seed’s growth.”
Professor Makris and his colleague, MIT researcher Cadine Navarro, carried out experiments with rice seeds, which naturally grow in shallow watery fields.
Over a large number of repeated experiments, they submerged roughly 8,000 individual seeds of rice in shallow tubs of water and exposed sections of them to dripping water.
They varied the size and height of each water droplet to mimic raindrops during light, moderate, and heavy rainstorms.
The researchers also used a hydrophone to measure the acoustic vibrations created underwater by the water droplets.
They compared these measurements to recordings they took in the field, such as in puddles, ponds, wetlands, and soils during rainstorms.
The comparisons confirmed that their water droplets in the lab were generating rain-induced acoustic vibrations as in nature.
As they observed the rice seeds, the authors found that the groups of seeds that were exposed to the sound of water were able to germinate 30 to 40% faster than the seed groups that were not exposed to rain sounds but were otherwise in identical conditions.
They also found that seeds that were closer to the surface could better sense the droplets’ sounds and grow faster, compared to more submerged or more distant seeds.
These experiments showed that there is a connection between the sound of a water droplet and a seed’s ability to grow.
The researchers propose that there may be a biological advantage to seeds that can sense rain: if they are close enough to the surface to respond to the sound of rain, they are likely at an optimal depth to soak up moisture and safely grow to the surface.
The team then worked out calculations to see whether the physical vibrations of the droplets would be enough to jostle the seeds’ microscopic statoliths.
If so, this would point to the mechanism by which sound can directly stimulate a plant’s growth.
In their calculations, the scientists factored in a rain droplet’s size and terminal velocity (the constant speed that a falling object eventually reaches), and worked out the amplitude of sound vibration the droplet would generate.
From this, they determined to what degree these vibrations in water or soil would displace, or shake a submerged or buried seed, and how a shaking seed would affect microscopic statoliths within individual cells.
The authors found that the experiments they performed on rice seeds were consistent with their calculations: the sound of rain can indeed dislodge and jostle a seed’s statoliths.
This mechanism is likely at the root of a plant’s ability to ‘sense’ the sound of rain and grow in response.
“Brilliant research has been done around the world to reveal the mechanisms behind the ability of plants to sense gravity,” Professor Makris said.
“Our study has shown that these same mechanisms seem to be providing plant seeds a means of perceiving submergence depths in the soil or water that are beneficial to their survival by sensing the sound of rain.”
“It gives new meaning to the fourth Japanese microseason, entitled Falling rain awakens the soil.”
A paper describing this research was published this week in the journal Scientific Reports.
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N.C. Makris & C. Navarro. 2026. Seeds accelerate germination at beneficial planting depths by sensing the sound of rain. Sci Rep 16, 11248; doi: 10.1038/s41598-026-44444-1
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