Stand still anywhere for a few minutes and you will hear layers you usually filter out: wind in a gutter, a distant road, birds sorting out their territories, a fridge humming through a wall. Acoustic ecology is the practice of paying attention to those layers and asking what they say about a place.
It began in the late 1960s as a blend of music, activism and research, and it has since grown into a scientific field as well. Artists, composers, biologists and urban planners now all use its ideas, often without realising they share a common root.
This guide explains where acoustic ecology came from, the vocabulary it gave us, how it differs from soundscape ecology, and how artists use it in their work today.
What acoustic ecology means
At its simplest, acoustic ecology studies the relationship between living beings and their sonic environment. It treats sound not as background noise but as information about the health, history and character of a place.
The idea carries a quiet ethical charge. If the sounds around us shape how we feel and behave, then the noise we add to the world is not neutral, and listening carefully becomes a way of caring for an environment.
You will sometimes see the term sound ecology used as a looser synonym. Both point to the same basic question: what does this place sound like, and what has changed it?
The World Soundscape Project in Vancouver
The movement took shape around the Canadian composer R. Murray Schafer at Simon Fraser University in British Columbia. Around 1969 to 1970, troubled by rising noise in Vancouver, he gathered a small group of composers and researchers into what became the World Soundscape Project.
The group included Barry Truax, Hildegard Westerkamp, Peter Huse, Bruce Davis and Howard Broomfield. Rather than campaign against noise alone, they set out to document what their city actually sounded like.
The result, The Vancouver Soundscape, appeared in 1973 as a set of recordings with a booklet. It mapped harbour horns, church bells, traffic and the voices of the waterfront, treating a city's sound as something worth recording and preserving.
The group then travelled through Europe and recorded five villages for Five Village Soundscapes, published in 1977. One of them was Skruv in southern Sweden, alongside villages in Germany, Italy, France and Scotland, which gives the project an early Nordic chapter.
A vocabulary for listening
Schafer's book The Tuning of the World, also from 1977, gave the field much of its language. Later editions carry the title The Soundscape: Our Sonic Environment and the Tuning of the World.
He described keynote sounds as the constant backdrop of a place, like wind, sea or traffic, heard so often that people stop noticing them. Sound signals are the foreground sounds we consciously attend to, such as bells, horns and alarms.
Soundmarks, by analogy with landmarks, are sounds that are unique to a community and valued by it. A particular foghorn or the bells of a local church can become part of how people recognise home.
He also contrasted hi-fi and lo-fi soundscapes. In a hi-fi environment, such as a quiet countryside at night, individual sounds can be heard clearly and from far away. In a lo-fi environment, such as a busy street, sounds mask one another until little stands out.
The Handbook for Acoustic Ecology
In 1978 the project published the Handbook for Acoustic Ecology, edited by Barry Truax. It works as a dictionary of terms drawn from acoustics, psychoacoustics, music and environmental studies.
The handbook mattered because it gave artists and scientists a shared reference point. A composer and an acoustician could look up the same term and mean the same thing.
Truax later produced an expanded second edition on CD-ROM in 1999. It remains a useful starting point for anyone who wants precise definitions rather than loose talk about soundscapes.
Soundwalks and the artist as listener
Hildegard Westerkamp developed the soundwalk into one of the field's most widely used practices. A soundwalk is simply a walk taken with the aim of listening, sometimes in silence, sometimes guided, sometimes with a recorder.
Her piece Kits Beach Soundwalk, from 1989, uses her own narrating voice over a recording of a Vancouver beach. She talks the listener through what they are hearing and quietly filters out the city's hum, which turns the piece into a lesson in attention.
This emphasis on listening links acoustic ecology with the work of Pauline Oliveros, whose idea of Deep Listening and the practice of paying attention to sound developed in the same decades. Both treat listening as a skill that can be trained rather than a passive sense.
In 1993 the World Forum for Acoustic Ecology was founded at a conference in Banff, Canada. It links regional groups around the world and publishes the journal Soundscape.
Bernie Krause and soundscape ecology
A different strand comes from Bernie Krause, an American musician who worked with early Moog synthesisers before turning to recording wild places. He founded Wild Sanctuary and spent decades building an archive of natural soundscapes from habitats around the world.
Krause proposed three categories that are now widely used. Biophony is the sound made by living organisms, geophony is the sound of non-living sources such as wind, rain and water, and anthropophony is sound made by people and their machines.
He also suggested that animals in a healthy habitat tend to share the acoustic spectrum, each species occupying its own range of frequency and timing, like instruments in an orchestra. He called this the niche hypothesis, and it gave his 2012 book its title, The Great Animal Orchestra.
One of his best-known examples comes from Lincoln Meadow in California's Sierra Nevada. Recordings made before and after selective logging in the late 1980s sound strikingly different, even though photographs of the site look much the same.
Where science took the idea
Krause's approach fed directly into soundscape ecology as a formal science. In 2011 Bryan Pijanowski and colleagues, Krause among them, published a paper in BioScience that set out the field as the study of sound in the landscape.
Researchers now place automated recorders in forests, reefs and wetlands and analyse the results with acoustic indices. These measures try to summarise how busy, varied or disturbed a soundscape is over days and seasons.
A related field, ecoacoustics, uses similar methods to monitor biodiversity. For artists, these developments mean there is a growing body of scientific recordings and methods to learn from, borrow carefully or push against.
How artists work with acoustic ecology today
For many artists, acoustic ecology is less a style than a set of habits. It starts with listening before recording, returning to the same place at different times, and noting what changes with season, weather and human activity.
Practical tools have changed, but the core skills have not. Our guide to field recording and how artists capture the sound of a place covers microphones, wind protection and patience, all of which matter as much now as they did for the Vancouver group.
Hydrophones and contact microphones have opened up sounds that humans cannot hear unaided. Artists record rivers, ice and the inside of trees, then build those recordings into compositions, installations and listening walks.
In the Nordic countries, this kind of work often sits inside academies and research programmes. Our piece on how Nordic institutions approach sound art as artistic research looks at how such projects are framed and evaluated.
Starting your own listening practice
You do not need equipment to begin. Choose a place you pass every day and stand there for ten minutes, writing down every sound you notice and which ones you would call keynotes, signals or soundmarks.
Return at a different hour or in a different season and compare your notes. Try sorting what you hear into biophony, geophony and anthropophony, and pay attention to which layer dominates.
If you want to go further, Schafer's The Tuning of the World, Truax's Handbook for Acoustic Ecology and Krause's The Great Animal Orchestra make a sound reading list. Together they show why listening to a place is never only about sound, but about how we choose to live in it.
About Dr. Mira Solheim
Dr. Mira Solheim is an art historian and writer focused on artistic research, Nordic visual culture and the intersection of art with technology and film. She writes for Artistic-Research.no on methodology, institutions and practice.