Biophony
Definition
Biophony is the collective sound produced at any one moment by all sound-producing organisms in a given habitat.[1] The term was coined by Bernie Krause, born 1938, musician and soundscape ecologist, who founded Wild Sanctuary in 1968 to record and archive natural soundscapes.[1]
Krause developed the concept while working at the research sites of Jane Goodall in Gombe, Tanzania, Biruté Galdikas at Camp Leakey in Borneo, and Dian Fossey at Karisoke in Rwanda.[2]
Components
Krause divides a soundscape into three components. With his colleague Stuart Gage, then at Michigan State University, he added the first and third to complete the set.[2]
Geophony. Non-biological natural sound: wind in trees or grasses, water in a stream, waves at a shore, movement of the earth.[1] Krause identifies these as the first sounds on Earth, present before anything existed to hear them.[3]
Biophony. The collective signature produced at one time by all sound-producing organisms in a habitat.[1]
Anthropophony. Human-generated acoustic signals.[1] Krause splits this into two subsets: controlled sound such as music, language, or theatre, and incoherent or chaotic sound, ordinarily called noise.[3] A colleague proposed technophony for the second subset, and Krause has said he encourages people to coin their own terms for this material.[3]
Acoustic Niche Hypothesis
The organizing claim behind biophony. The hypothesis extends the ecological niche concept onto the spectro-temporal plane of the soundscape: as niche differentiation leads species to divide up the physical resources of an ecosystem, so species differentiate their use of its sonic resources.[4]
The differentiation occurs on two axes: spectrally, in the frequencies animals use to vocalize, and temporally, in the time-based patterns of their calls.[4] In a healthy habitat, the channels of transmission and reception are reserved for and occupied by particular species.[3] The theory predicts that older, more mature ecosystems show greater differentiation between the auditory niches long-established species occupy.[4]
John Endler proposed the mechanism in 1992: sexual selection operating on a mate's ability to hear a call, together with the requirement to hold territory.[4] A call that overlaps another species' bandwidth is a call that fails, and failure carries a direct reproductive and survival cost.
Krause has described his own realization in these terms. Listening through headphones, a habitat that had sounded like cacophony resolved into a partitioned collection of voices, each one placed in its own acoustic bandwidth, which he compared to the structure of a Mozart symphony.[5] The point of the observation is that individual animals do not experience their world as separate voices, but as a simultaneity of many signals, ebbing and swelling from quiet periods into dawn and dusk choruses.[5]
Habitat Health Measurement
Soundscape ecology evaluates habitat status from the biophony, with indicators including changes in biophonic and geophonic structure caused by global warming and by habitat transformation from natural or human causes.[6]
Krause tested this at four representative sites in Sequoia National Park, recording biophonies and geophonies at selected times across four seasons from October 1991 to August 1992, and analyzing the results with respect to frequency niches and temporal expression of sound.[6]
The practical finding is that a spectrogram of a healthy habitat shows occupied bands across the frequency range, and that disturbance shows up as bands going empty. This registers before species counts do, because a recording captures the whole assemblage at once and does not require anyone to find the animals.
The US National Park Service commissioned Krause to write a training guide for interpretive rangers, introducing park visitors to quiet zones, critical listening, and recording of natural soundscapes.[6]
Anthropophony as Interference
This framework treats human sound as occupying bandwidth that other organisms need, which is a specific claim rather than an aesthetic one. Road noise, aircraft, and machinery mask calls in the frequency ranges they overlap, and the affected animals either shift their calls, call louder, call at different times, or fail.
Krause reports a case at the San Diego Zoo in 1990 in which an installed ambient soundscape was wrong for the habitat it accompanied, agitating the gorillas to the point that staff had to shut the system off, at a cost of over 300,000 US dollars.[6]
That case is worth attention for anyone designing sound into an environment. The system was not too loud. It carried the wrong information for its setting, and the animals it addressed could tell.
Relation to Designed Sound
The acoustic niche hypothesis describes a working solution to a problem interface designers face directly: multiple sources needing to signal into a shared channel without masking each other. Evolution solved it by partitioning frequency and time, so that each signal has a reserved band and a slot.
Devices in a shared room have no such arrangement. Notification tones from separate manufacturers land in overlapping frequency ranges with no coordination, and the result is a soundscape with no partition, in which each new signal degrades the legibility of the others.
Further Reading
- Acoustic Ecology
- Low Resolution Indicators
- The Feeling of Space
- Sensorium: Embodied Experience, Technology, and Contemporary Art
- Rhythm Science
- The Silent Language
- Between Nature & Culture Cyborgs, Simians, Dogs, Genes & Us
- The Companion Species Manifesto: Dogs, People, and Significant Otherness
- Culture and Space: Conceiving a New Cultural Geography
- Digital Ground: Architecture, Pervasive Computing, and Environment
- Understanding Media: The Extensions of Man
Key texts
- Krause, Bernie. The Great Animal Orchestra: Finding the Origins of Music in the World's Wild Places. Little, Brown, 2012.
- Krause, Bernie. Wild Soundscapes: Discovering the Voice of the Natural World. Wilderness Press, 2002.
- Krause, Bernie. "The Niche Hypothesis." The Soundscape Newsletter 6 (1993).
- Pijanowski, Bryan C., et al. "Soundscape Ecology: The Science of Sound in the Landscape." BioScience 61, no. 3 (2011): 203-216.
- Schafer, R. Murray. The Soundscape: Our Sonic Environment and the Tuning of the World. Destiny Books, 1977.
External Links
References
- ↑ 1.0 1.1 1.2 1.3 1.4 Bernie Krause, Wikipedia.
- ↑ 2.0 2.1 Bernie Krause, Climate One.
- ↑ 3.0 3.1 3.2 3.3 Bernie Krause on The Great Animal Orchestra, The Wire.
- ↑ 4.0 4.1 4.2 4.3 An artificial life approach to studying niche differentiation in soundscape ecology, arXiv.
- ↑ 5.0 5.1 Everything Is Wrong: Bernie Krause's Concept of Biophony, MIT Press Reader.
- ↑ 6.0 6.1 6.2 6.3 Bernie Krause research profile, ResearchGate.
