Honeybee flying to pink Nemesia flower Honeybee flying to pink Nemesia flower Honeybee flying to pink Nemesia flower. (Photo: Sumikophoto / Shutterstock)

Flowers can actually hear buzzing bees and human voices

Israeli researchers discover how plants surprisingly respond to certain sounds.

Next time you find yourself tending to your flower garden, you may want to stay quiet. The flowers are listening.

The latest news comes out of Israel where scientists in the zoology and plant sciences departments at Tel Aviv University discovered how plants respond to the buzzing of bees. The plants hear bees approaching and attempt to lure them in with sweeter nectar.

In several experiments, they found that playing audio recordings of buzzing bees around certain flowers will cause the sugar concentration in the nectar to rise by about 20% in less than five minutes. Such a rapid reaction by plants to sound had never previously been reported.

Just to compare, the researchers also tried a higher frequency noise – like that made by a mosquito or a bat – and the flowers did not respond. The study was conducted in both a quiet environment in a laboratory and, for comparison, on a Tel Aviv beach with lots of ambient noise. Flowers in the lab were also tested with and without a sound-proof glass on top of them.

Flowers vibrate in response to sound, and increase nectar sugar concentration (right). Glass covered flowers do not respond (middle). Flowers vibrate in response to sound, and increase nectar sugar concentration (right). Glass covered flowers do not respond (middle). (Photo: Tel Aviv University)

The authors point out that the behavior is actually in line with the natural order of things, considering that a plant's ability to sense its environment and respond to it is critical for its survival. So, it would seem, plants have some sort of consciousness.

Can plants actually hear? Well, this is not the first time that they've reacted to what they're hearing around them. In a 2009 study, Britain's Royal Horticultural Society found that women's voices help make plants grow faster. In that experiment, tomato plants were found to grow up to two inches taller when they were tended to by a female gardener. "The findings vindicate comments made by Prince Charles that he talks to his plants, although they suggest that for maximum results he would be better off recruiting the Duchess of Cornwall," wrote The Telegraph at the time.

More recently, a 2017 Australian study found that some flowers were able to sense noises, such as the flow of water through a pipe. "Sound vibrations could trigger a response of the plant via mechanoreceptors – these could be very fine, hairy structures, anything that could work like a membrane," biologist Michael Schöner told Scientific American magazine.

The ability of inanimate objects to hear what's around them may seem like something out of a science fiction novel, but it's real. What if we told you that a potato chip bag left on the floor of a break room could listen in on office gossip? You'd think we were crazy, right? Think again.

It's possible thanks to a team at MIT, Microsoft and Adobe. They found that as people were talking around the potato chip bag, they were sending teeny-tiny sound vibrations into the air. Those vibrations then hit inanimate objects around the room. Now imagine if you had a camera that was zoomed in on one of those objects extremely closely. In theory, you could actually see the object (like a potato chip bag) move along with the vibrations. You could then feed that video into a computer program that could decipher the vibrations and – voila! – you can play back the audio of the conversation that just took place. You're basically turning everyday objects into visual microphones.

So the next time you're at the botanical gardens or in a grocery aisle, careful what you say. Someone – or something – might be listening.

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Flowers can actually hear buzzing bees and human voices
Israeli researchers discover how plants surprisingly respond to certain sounds.