If A Tree Falls In The Forest Can A Tree Hear It?

Posing the age-old question: If a tree falls in an empty forest can anyone hear it seems rhetoric at this point in time. However according to new research this presupposition might not be quite accurate. Yes, of course humans would not be able to hear it, but what about other lifeforms?

What's the buzz?

Until now, we were under the impression that plants couldn't hear nor talk? The latest experiments in auditory research however shows that some' plants can hear the sounds of animal pollinators, and as a result react quickly by sweetening their nectar." What a treat for those bees, eh?

This research comes from Lilach Hadany and Yossi Yovel at Tel Aviv University who also learned that plants will make high-pitched noises that lie beyond the scope of human hearing, but can nonetheless be detected by fellow plants.

Doubting Thomases?

Some of these researchers argue that plants are surprisingly very talkative. Others have doubted these findings. Their views on the new studies wasn't partisan however. Almost 100-percent agreed with the assertions that plants can hear -- but were skeptical about the ability for plants to chat it up. Those dissenting views go to show how controversial this line of research still is, and how difficult it is to surface conclusive evidence of plants.

Like Tom-toms & the internet

There is another theory that plants can send airborne, chemical messages that warn their distant relatives about marauding plant-eaters, similar to how Native American Indians use to send messages via tom-toms.

Plants can also communicate with one another through the network of fungi that connects their roots—a so-called "wood-wide web." And they can respond to vibrations moving through their tissues: For instance, many can release pollen when insects land on them and buzz at the right frequency, while others create defensive chemicals when they sense the rumbles of chewing insects.

Cause and Effect

“This shows yet again that plants can behave in remarkably animal-like ways,” says Heidi Appel from the University of Toledo, who has studied plant responses to animal vibrations. Crucially, she says, the study is “ecologically relevant”—that is, it involves a sound (bee buzzes) and a response (nectar sweetening) that actually matter to the plant. This is much different from past studies that showed plants reacting to sounds they would never normally encounter, such as classical music.

This research shows that plants responding in such a fashion make clear evolutionary sense. Sweeter nectar is more attractive for pollinators, and by attracting more pollinators, the plant increases its odds of producing more of its kind.

Where are their ears?

But if plants can hear, where are their ears located? The researchers believe its in the flowers themselves. They used lasers to show that the primrose’s petals vibrate when hit by the sounds of a bee’s wing beats.

If they covered the blooms with glass jars, those vibrations never happened, and the nectar never sweetened. The flower acts like the fleshy folds of our outer ears, channeling sound further into the plant. But where? No one knows just yet! “The results are amazing,” says Karban. “They’re the most convincing data on this subject to date. They’re important in forcing the scientific community to confront its skepticism.”

Convincing Critics

To convince their critics, Hadany and Yovel clearly need to do more experimenting. They’re already planning to repeat their study in a more natural outdoor setting to see whether those sounds carry amid ambient noise. “We also need to test specific relevant organisms to see if they respond,” says Hadany. “And, of course, the most exciting prospect for us is: Are plants capable of hearing the sounds of [other] plants?” Or is there a difference from one species to another? So, indeed . . . time will tell whether or not if a tree falls in the forests, another tree will be able ask why?

Primary Source: The Atlantic