Acoustic ecology is the study of the relationship between living beings and their sonic environment, and of how that environment changes over time. It grew out of the World Soundscape Project, started in 1969 by the composer R. Murray Schafer at Simon Fraser University in British Columbia, with early associates including Barry Truax and Hildegard Westerkamp. Schafer’s book The Tuning of the World (1977) set out its vocabulary: the soundscape as the sum of the sounds in a given area, keynotes that form a constant background, and soundmarks unique to a particular place.
The movement acquired an international body in 1993, when the World Forum for Acoustic Ecology was formed at a conference in Banff, Alberta. Its emphasis on attentive listening shaped field recording and soundscape composition, and it offers drone listeners a useful lens: the hum of traffic, ventilation and electrical supply is itself a keynote, an unintended drone that much experimental music borrows, amplifies or tries to escape.