The sound of (natural) silence

Scotland's natural soundscapes are more and more under threat from manmade noise pollution – from urban expansion, from the growing strain on our transport infrastructure, from rapidly developing technologies. I think it's important to to raise awareness of this issue. Research such as mine can help us understand the condition of our soundscapes and perhaps encourage new or reformed environmental policies.

I've made sound all my life in the form of music and I've always enjoyed being out in nature. I've been a musician for as long as I can remember. I play at weddings with string quartets. I do session work and have played in orchestras over the years, and having written so much music, and worked with people making noise, I had the idea of looking for places where you can find natural silence, and to study the environmental impact of noise on our lives.

What I'm doing, really, is searching for the naturally quietest places in Scotland. Natural silence devoid of manmade noise intrusion. When I tell people I'm looking for natural silence there's a wee bit of confusion, because it's not literal, complete silence – it's places where there is no manmade noise pollution.

Scotland is a good place compared to other countries in the UK to be doing this sort of research. I'm creating an archive of sound recordings, recorded in ambisonics – a sound-recording technology that can record 360-degree sound fields for immersive, surround-sound playback.

There might seem to be an irony in that I'm taking a microphone out into the wilds and often recording nothing, but I've found there's a beauty in recording nothing. It's evidence that there are still places where you can experience true peace and quiet, and feel truly alone with nature.

It's not strictly scientific, this project: I'm not looking for absolute, perfect silence. But I have taken recordings where it has been very quiet. During each recording I take notes of wildlife, the geographical features, the weather, GPS locations and sound-level readings to add to the archive data. The idea is that one day people will be able to return to this archived data. In the future, a lot of these soundscapes might, after all, become lost to the effects of over-industrialisation, rising population and growing transport infrastructure.

It's also about being able to exhibit the beauty of natural soundscapes with the aim of raising awareness of the importance of preserving them. I'm interested in places with a complex balance of different biological, meteorological and geological sounds. Soundscapes are like invisible landscapes – we can't physically see them, and we can forget they are there, but they're very complex and share a lot of the features that physical landscapes have. The topography of a soundscape is formed by complex peaks and troughs in sound pressure level across the frequency spectrum. We as humans share these acoustic landscapes with other living beings and must consider the environmental implications of the ways in which we choose to occupy our acoustic environment.

For example, birds are known to alter the natural loudness and pitch of their calls to be heard within the manmade noise of the city. Entire pods of whales are regularly stranded on beaches around the world because they can’t communicate and echo-locate due to the high levels of noise pollution in the planet's oceans.

I've been down to the southernmost point of Scotland, the Mull of Galloway, and as far north as Orkney. I've gone east as far as St Abbs, and I've been up to Aberdeenshire, and to Loch Sunart, and the Ardnamurchan peninsula on the west coast. The Highlands and islands, too. I think I have a nice spread of data.

It's been interesting to see how the physical landscape affects sound. On the east coast, especially Aberdeenshire, the land is relatively flat, which allows sound to travel longer distances, resulting in an expansive soundscape. It's good farming land. There is roughly three times the population density in the east of Scotland than in the west which causes significantly higher levels of manmade noise pollution. On the west coast however the soundscapes are much more localised – the lochs and mountains contain sound within their rifts and valleys, and the wetter, windier climate results in a particularly dramatic and diverse sound environment.

My favourite sound is that of waves on the coast. Waves don't actually make any noise when they're out in the ocean. They're quite silent, but it’s when they hit the shore that you hear them. In the same way, if you're standing on a mountain in the Cairngorms, the mountain itself doesn't make any noise. It's the elements rushing over it that make the sound – it's the water, it's the meteorological activity, and the biological activity – the wildlife is a big part of that. In the Cairngorms, in the big valleys, the deer would come down and graze freely because there was no other intruding sound, and it was quite quiet. If I were up there now, I'd expect to hear a balance of meteorological sound and biological sound.

I live in the city and am aware of the health implications of noise pollution. Getting out to somewhere where you open your ears and not hear a single manmade noise ... Even though I knew what I was expecting, I didn't expect to feel very, very isolated, in a way I never really did before. There aren't many places left where you can sit for 30 minutes and not hear an aircraft. If you can manage to get that kind of experience of complete isolation, it can almost be an out-of-body experience. There's a purity to it.

I urge people to take "sound walks" in which they explore their acoustic environment with their ears as opposed to their eyes. You can do it in the city. You can go out and wander around, and listen, and note what you hear: you suddenly realise the complexity. When you get out into the wild and experience real natural silence, you realise that peace and quiet go hand in hand.

Cavan Campbell is a music teacher, acoustic ecologist, violinist, violist, composer and sound artist. He has a Masters of Design in Sound for the Moving Image from the Glasgow School of Art's Digital Design Studio and studied for his undergraduate Bachelor of Music degree at the Royal Conservatoire of Scotland. Visit cavancampbell.com. One of Cavan's natural soundscapes can be heard on the HeraldScotland website at xxxxxx.