It's only in the last 250 years, since the Industrial Revolution, that human beings have started to live in places where there is little natural sound. Most of the time it was the only sound: the odd war would make a lot of noise, and there were loud local events like conversation, workmen, or church bells, but all these were noticeable mainly because they were relatively rare compared to biophilia. Anywhere you found humans on the planet, the soundscape used to be dominated by natural sound.

In my opinion we have developed a symbiotic relationship with biophilic sond. It makes us feel comfortable because it has always been there and connects us with our primative selves. For this reason it’s important that we develop a respect and understanding of natural sound and take this into account when we design the sound of the spaces we inhabit today.

Wind

Wind has a huge dynamic and timbral range, from the susurrance of gentle zephyr that offers a moment's relief from the heat of a desert day to the deafening roar of the strongest winds on Earth during the dark winters of the Antarctic. We hear wind in leaves, in grass, over rock, moving sand and dirt, and against the flaps of our ears.

Wind sounds subtly define the rest of our natural environment. Think, for example, of the difference between the percussion of fleshy mid-Spring leaves, brittle late-Summer leaves, and mid-Winter twigs. We know and respond to these tiny signals instinctively; they help give us our bearings every day and ground us securely in our surroundings.

Water

Water's main songs are pitter-patter of rainfall, streams and rivers, and of course the ocean. As with wind, its range is enormous, from the gentlest burbling of a tiny brook to the overwhelming all-frequency bombardment of a mighty waterfall. Water is life-giving, the essence of our survival; we find its gentler sounds soothing and restful.

“These slow, whooshing noises are the sounds of non-threats, which is why they work to calm people,” said Orfeu Buxton, an associate professor of biobehavioral health at Pennsylvania State University. “It's like they're saying: 'Don't worry, don't worry, don't worry.”

Birdsong

Birds, and in particular songbirds, densely inhabit the same regions we do: the temperate and tropical regions. Some birds sing exquisitely beautiful songs while other croak or squawk.

Birdsong becomes more and more amazing as you study it: slow down the lightning-fast song of a thrush or of the diva of songbirds, the lyrebird, and you find complex, repeating structures that combine rhythms that would challenge most master percussionists with pitch sequences and modulations that use more notes, subtler relationships and levels of vocal gymnastics way beyond any human. It sounds like virtuoso jazz played at breakneck speed – and then you remember that this is slowed down to one quarter of the original delivery pace.

Birdsong is nature’s alarm clock. Birdsong is nature’s alarm clock.

David Rothenberg ’s book Why Birds Sing goes into this topic in detail, and is highly recommended, though he doesn’t consider the psychoacoustic question we need to consider here: what does birdsong do to human beings?

At the most basic level, birdsong tells us that we are safe. We have learned over countless millennia to use the ceaseless diurnal vigilance of the birds, turning them into unpaid guards by virtue of their practice of changing their song, or most often falling silent, if danger approaches. When the birds are singing, all is well. It’s when they stop singing that we need to be on alert. I suspect that a sudden cessation of birdsong will still create a release of cortisol and adrenaline, the fight/flight hormones, in a modern human being.

Birdsong is nature’s alarm clock. When the birds start singing, it’s generally time to get up, so we associate birdsong with being awake and alert. Thus birdsong can make people feel cognitively alert.

And birdsong connects us with the world. There may be some element of feeling not alone in this, of being in the company of other living things that are no threat to us. Birdsong seems to affirm life and the joy of it (and there is good reason to believe that this is actually why birds are singing for much of the time).

It seems natural for us to take aesthetic pleasure in one of the planet’s signature sounds – one that has been there far longer than we have, according to current theories. Our developed appreciation of birdsong may be there because listening to it is a significant physical manifestation of our connection with nature – a connection that modern living has severed for many millions of people.

Whatever the reasons, birdsong is enduringly popular. Musicians have always been fascinated by it: Mozart kept a trained starling to listen to, and Messiaen attempted to recreate birdsong in his later music, though most birdsong is impossible to transcribe. It’s not only trained professionals who appreciate the uplifting nature of birdsong: in the UK, a British Trust for Ornithology CD of nightingale song rushed off the shelves as fast as they could be restocked, as did the British Library’s Dawn Chorus CD. Maybe this is because, as a study by Reading University found, encounters with the natural world boost mental health by giving ‘a sense of coherence.’

The loss of biophilic sound

Since the industrial revolution, our everyday soundscapes have changed dramatically. They are composed of much starker, more noticeable sounds, like road vehicle engines, tyres and horns, trains, planes, a plethora of varied warning tones, and other people’s conversation.

I believe the removal of biophilia and its replacement with urban sound has created two results. The first is stress. Instead of a soothing wash of stochastic sound, our sound processing system is having to work overtime to suppress a barrage of sudden, loud noise all day. This is hard work, and not surprisingly it’s tiring. Many people have to work in places where the ambient noise level is well over 80 decibels, and there is plenty of research to show that their physical and mental health suffers as a result.

I also suggest that the loss of biophilic sound from our urban surroundings has left us with a vague feeling of loss: we know we ought to be listening to something, but we don’t know what it is – so we put on music, or the radio or the television, just to have some background noise, or find comfort in café hubbub.

The natural world gives us so much. It’s important that we develop a respect and understanding of natural sound and take this into account when we design the sound of the spaces we inhabit today.