If a Tree Falls in the Forest, and There’s No One Around to Hear It, Does It Make a Sound?

Have you ever heard of the philosophical thought experiment of a falling tree in a forest? The question goes like this: If a tree falls in the forest, and there is no one around to hear it, does it make a sound?

Despite it appearing trivial at first instance, it has inspired intellectual debate for centuries and continues to interest people today.

The question first appeared in The Chautauquan magazine in 1883, which asked: “If a tree were to fall on an island, and there were no human beings, would there be any sound?”

It answered: “No. Sound is the sensation excited in the ear when the air or other medium is set in motion.”

It has attracted scientists and philosophers in its current form of the question since. Several scientific magazines have since made the case that sound is produced, despite the presence of a perceiver.

Therefore, on the one hand, there is a scientific explanation: a falling tree would emit sound waves whether or not anyone could hear them. Conversely, philosophers have argued that sound cannot exist without a conscious observer.

Therefore, even if the tree falls and no one is around to hear it, it doesn’t make a sound.

This article explores both scientific and philosophical dimensions of the philosophical thought experiment in detail and further discusses the broader implications of how we understand perception and reality.

The Scientific Answer: “Yes!”

According to science, if a tree falls in the forest, it would invariably emit sound waves even if no one is around to hear them. The air around a vibrating object also vibrates, sending sound waves into the atmosphere.

Physical phenomena include sound. When sound waves enter a human ear, the eardrum vibrates, sending impulses to the brain that are translated as sound.

When a tree falls, the ground and the air are both vibrated, which causes sound waves to be produced and propagate through the atmosphere. Even if no one were present to hear them, these sound waves would remain.

In reality, there are several more sounds in nature that are produced but are not audible to people, such as those made by insects or other creatures that are audible to other animals but not to humans.

Although it is true that sound waves require a medium to travel through, such as air, water, or solid material, the physical process that generates sound waves is unaffected by the lack of a conscious observer.

So, from a scientific standpoint, the answer to the question of whether a falling tree makes a sound if no one is around to hear it is a resounding “yes.”

Evidence to Support Scientific Explanation

One of the essential scientific pieces of evidence to support this claim is that sound waves can be measured and found using equipment like seismometers or microphones.

These devices can find and capture sound waves even when no conscious observer notices them. This shows that independent of how humans perceive them, sound waves are a real physical phenomenon that can be observed, measured, and investigated.

Moreover, there is a lot of mystery around us. We cannot really hear all that we see around us.

For instance, many insects and animals in nature create sounds beyond our hearing range.

Bats and whales, for example, create high-pitched sounds beyond our listening scope. Volcanic eruptions and earthquakes, again, are not audible to human ears in most cases. But does that mean that there is no sound?

Definitely, not—at least scientifically.

The Philosophical Answer: “It’s Complicated!”

While it may seem easier on a scientific basis to answer if a tree falls in the forest, it makes a sound, irrespective of whether one hears it or not, the philosophical implications of the subject are somewhat complex.

Since the inception of philosophy, the nature of reality and perception has been debated passionately.

Subjective Idealism

In this debate, one of the schools, Subjective Idealism, holds that perception is the only thing that exists. From this viewpoint, if there is no conscious observer to hear a sound, the tree may not have made any sound.

In other words, if no one is around to hear it, the falling tree doesn’t create a sound since the experience of sound depends on a conscious observer.

As the 16^th-century philosopher-astronomer Galileo Galilei wrote,

I think that tastes, odours, colours, and so on are no more than mere names so far as the object in which we place them is concerned and that they reside only in consciousness. Hence if the living creature were removed, all these qualities would be wiped away and annihilated.

(Galileo, 1623)

In his celebrated 1710 work, A Treatise Concerning the Principles of Human Knowledge, philosopher George Berkeley makes a case for an absurd world independent of our conscious mind. He writes:

It is indeed an opinion strangely prevailing amongst people that houses, mountains, rivers, and in a world all sensible objects have an existence natural or real, distinct from their being perceived by the understanding… for what are the forementioned objects but things we perceive by sense?

And what do we perceive besides our own ideas or sensations?

And is it not plainly repugnant that any one of these or any combination of them should exist unperceived?

(Berkeley, 1710)

Berkeley adds:

But, say you, surely there is nothing easier than for me to imagine trees, for instance, in a park, or books existing in a closet, and nobody by to perceive them.

The objects of sense exist only when they are perceived; the trees therefore are in a garden… no longer than while there is somebody by to percieve them.

(Berkeley, 1710)

In essence, what these philosophers argue is that, without us, nothing else makes sense. Berkeley further makes the case that the world is in our minds. Our experiences would depend on us being there.

Therefore, the smell of perfume, the touch of someone, the taste of ice cream – all depend on us and our ability to make sense of them.

Let’s remove consciousness from us. Then, we would all have an odourless, colourless, soundless world. How bland?

In defence of subjective idealism

An essential defence of subjective idealism is the assumption that perception is necessary for reality to exist. Without a perceiver to see and comprehend the physical world, there cannot be an objective reality.

Therefore, if there is no conscious listener to pick up the sound waves created by the falling tree, the sound cannot exist.

Another defence could be the belief that sound results from human perception. This theory proposes that sound is not an objective property of the physical world but a conceptual construct the brain generates in response to physical stimuli.

So, there cannot be sound if there is no conscious observer to pick up the sound waves.

Objective Realism

The Objective Realist perspective, on the other hand, asserts that reality exists devoid of one’s experience. According to this viewpoint, the falling tree would produce sound waves whether or not someone was around to hear them.

Regardless of how humans perceive or interpret them, sound waves will still exist as a physical phenomenon.

Most of us fall into this category. We assume the perceiver’s presence does not change whether the tree fall makes a sound.

There exist many unobserved events in the everyday lives of humans. The British philosopher of critical realism, Roy Bhaskar, in his Realist Theory of Science, argued:

If men ceased to exist sound would continue to travel and heavy bodies to fall to the earth in exactly the same way, though ex hypothesi there would be no one to know it.

(Bhaskar 1975)

In defence of objective realism

Objective realism posits that reality exists devoid of human perception. This perspective notes that the physical world exists with or without humans and their ability to interpret it.

This sounds logical.

Sound waves would exist, irrespective of whether one hears them. The mere absence of an entity that can perceive cannot make the whole phenomenon not occur.

In another defence, science tells us that sound can be measured through instruments even without human presence, which challenges one’s ability to capture it. Let’s say my recorder is lost in the forest.

It may record a tree falling. Even when I am not there to listen to the tree falling, my recorder may have captured it.

By default, I could hear it later—and know that there was a sound when the tree fell and that my recorder captured it. And I didn’t need to be there. This simple fact makes the realist argument much more robust against the idealist position.

What does it mean to answer if a tree falls in the forest?

This is not so difficult a question to arrive at an answer. It just really depends on what you think is reality. When you think of what makes for reality is when it gets complicated.

If you believe that sound could only exist in human consciousness, then our full societal and worldly understanding has to be reversed. We need to re-evaluate our entire understanding of the world.

Let’s say you thought it was challenging to do all that. So, for argument’s sake, you agree that sound exists independent of human perception.

When you argue this case, you must also acknowledge that human sensory experience is limited—and our ability to experience reality is fairly limited.

In Conclusion

For millennia, philosophers have debated if a tree falls in the forest, does it makes a sound even if no one is around to hear it?

Its answer is complicated.

The answer provided by science is that sound waves are created whether or not a listener can hear them.

The philosophical argument, however, focuses on whether or not sound necessitates the existence of a conscious observer. According to some, sound cannot exist without an observer because it is a by-product of human consciousness.

Others dispute this claim by asserting that sound is an impersonal physical phenomenon that occurs regardless of how humans perceive it.

These arguments raise an essential question about perception, reality, and our existence in the world.

Dear reader, what do you think?

Cover Photo by Lukasz Szmigiel on Unsplash