BRIEFING By Claire Thirlwall 1. Soundscape of Mount Rainier, showing marmot, bird, insect and aircraft noises. © National Park Service
Climate change resources – sound and light Could sound recordings of the landscapes we work in provide insight into the impact of climate change?
A By recording the biophony at the same location, at the exact same time of day or night and using similar recording equipment, changes in density and diversity can be detected.
¹
P Aspden, ‘The Great Animal Orchestra – collecting the sounds of endangered lives’, 2019, https:// www.ft.com/ content/64202126deb5-11e9-b8e0026e07cbe5b4 [accessed 18 February 2021].
2
B Krause, S Gage & W Joo, ‘Measuring and interpreting the temporal variability in the soundscape at four places in Sequoia National Park’, in Landscape Ecology, vol. 26, 2011, 1247-1256.
s landscape architects the focus of our work is often on the visual elements of a landscape. However, the work of pioneering sound ecologist Bernie Krause shows that the aural elements can provide insight into the health of ecosystems. Detroit born Krause began his career in the late 1950s as a musician, initially performing with the folk band The Weavers and then becoming an exponent of electronic music. He worked in music and film until the late 1970s, and his work includes the synthesised sound of helicopter rotor blades for the iconic opening sequence of Apocalypse Now.1 From 1979, Krause concentrated on the
recording and archiving of wild, natural soundscapes from landscapes around the world. In 2001 Krause and his colleague Stuart Gage were commissioned by the US National Park Service to “quantify and assess the diurnal and seasonal character of the park’s soundscape.” The recording sites were selected to represent a combination of elevation and vegetation diversity.2 As part of this work the team developed three terms to define the sources of sounds. These are: Biophony: the collective acoustic signal generated by all non-human sound-producing organisms in a given habitat at a given moment, such as insect noise, birdsong or animal calls.
Geophony: naturally occurring nonbiological sounds, such as water, wind or thunder. Anthrophony: human generated sound, either direct, indirect or via electromechanical devices, such as voices, traffic or music. By recording the biophony at the same location, at the exact same time of day or night and using similar recording equipment, changes in density and diversity can be detected. One way to show these changes in the ecosystem is to use a spectrogram (fig 1) – a visual representation of the sounds recorded, with the vertical axis representing the sound frequency and the horizontal axis time.
1 51
