Murray Schafer: Acoustic Ecology and the Evolution of Soundscapes

This section presents the paradigm shift from traditional noise control to soundscape design and sustainable urban acoustic planning. Soundscape represents the internationally recognized definition of the acoustic environment as perceived or experienced by people in context, moving beyond decibel measurements to human-centered evaluation. Soundscape considers two dimensions: pleasantness (how enjoyable sounds are) and eventfulness (how dynamic they feel). Natural sounds typically create pleasant, calm experiences; technological sounds are commonly annoying; human voices create social presence. Research reveals distinct community preferences: urban parks should prioritize natural sounds and minimize crowd/technology noise; downtown areas accommodate natural sounds, individual voices, crowd noise, and some technology; rural areas feature natural sounds and individual voices while excluding crowds and technology. Practical applications include mapping what sounds people actually hear in different locations, categorizing them as technology, human, or natural sounds. Modern urban development requires integrating acoustics into architectural and planning practices. Outdoor noise increasingly affects indoor environments, creating tension between natural ventilation benefits and acoustic comfort requirements. Building facades can serve dual purposes as aesthetic elements and noise barriers. Transportation mode comparison reveals dramatic space differences: pedestrians require minimal space; cycling needs ~7x pedestrian space; cars require ~90x. Electric vehicles present new challenges—they operate too quietly, endangering pedestrians who rely on auditory cues, requiring research into appropriate noise levels.

This section demonstrates how acoustic considerations extend beyond individual buildings to urban planning and public space design. Every material and surface shape influences how sound behaves within a space, with reverberation—the persistence of sound after the source stops—creating spatial perception that makes spaces feel larger or smaller. Architectural elements like perforated ceilings and curved surfaces can amplify or diffuse sound intentionally. The section provides examples including stadium designs that amplify crowd chants for external perception, cathedral designs using specific geometries to create sacred acoustic experiences, and interactive public sculptures that guide sound paths. These applications show how acoustic design can be an intentional architectural element rather than merely addressing problems. Urban noise mapping procedures identify noise-sensitive areas near hospitals and residences, guiding development decisions. Computational models predict noise impacts of proposed developments, enabling proactive rather than reactive noise management. Understanding these relationships allows architects to manipulate materials and forms to achieve desired acoustic outcomes in both individual buildings and urban environments.

Public spaces should be designed like dressing rooms or public toilets where people can acoustically see and say anything they want. After emptying themselves, people can go back into the silent area. This represents a new approach to urban design that addresses acoustic pollution.

Soundscapes (acoustic environments) are a recognized concept in urban planning, particularly in developed countries. Acoustic design considers how different sounds affect people's mood, behavior, and wellbeing. Urban planning should incorporate acoustic considerations when designing new roads, commercial centers, hospitals, and residential areas. The challenge is that noise is energy that can potentially be utilized, making the question of what to do with urban noise a fundamental planning issue.

Effective urban noise management requires integrating acoustic considerations from the earliest stages of urban planning, using tools like soundscapes modeling, acoustic maquettes for scenario comparison, and specialized acoustic ventilation solutions to balance thermal comfort with noise reduction in public spaces.

Eco-acoustics is the scientific study of natural sounds in ecosystems including forests, maquis, and coral reefs. A soundscape consists of three components: geophony (natural sounds like wind and rain), anthropophony (human-made sounds), and biophony (animal sounds). Biophony gives each environment its unique acoustic character. Eco-acoustics analyzes the full range of frequencies where sounds are produced and characterizes how different animals occupy specific frequency spaces, creating unique acoustic signatures for each habitat. This approach offers rapid, standardized biodiversity assessment without requiring physical specimen collection.

Eco-acoustics and bioacoustics are scientific disciplines that use automated sound recording devices to monitor biodiversity by analyzing animal vocalizations, providing an autonomous, non-invasive method to track species populations and ecosystem health over time, which is particularly valuable for detecting biodiversity decline that may be invisible to human observation.

Wild soundscapes—comprising geophony (nonbiological sounds), biophony (animal-generated sounds), and anthrophony (human-generated sounds)—serve as powerful indicators of ecosystem health; changes in the density and diversity of biophony reveal environmental impacts that visual assessments alone cannot detect, as demonstrated by cases like Lincoln Meadow where selective logging dramatically reduced the soundscape despite appearing visually unchanged, and Mono Lake where jet noise disrupted synchronized frog choruses, leading to increased predation vulnerability.

Ecoacoustics studies the complete soundscape of a landscape, examining ecological processes at the ecosystem level. Bioacoustics focuses on individual animal sounds and communication. Sounds are essential for species communication, enabling mate finding, territory establishment, and predator warnings. The structure of sounds can change even when species numbers remain constant. Birds play crucial ecological roles including pest control and pollination, with some regions like Podocarpus National Park containing more bird species than all of Europe combined.

Biophony is a term introduced by Bernie Kraus in 1998 to describe the soundscape of an environment based on its acoustic sources. This encompasses all sounds produced by living organisms in a given habitat at a specific moment. Geophony refers to natural sounds produced by non-living elements of the environment, such as rain, river water, wind, and sand dunes. The video describes the sound of sand grains sliding down dunes as particularly fascinating, noting that it can induce a state of altered consciousness. Thunder sounds can be heard with specialized acoustic receivers, producing crackling sounds that resemble lightning somewhere on Earth, followed by an ascending and descending sequence that can travel very far into the Van Allen radiation belts.

Cities establish specific decibel limits for noise tolerance in residential and industrial areas. In São Paulo, residential areas allow 50 decibels during daytime (7 AM to 10 PM) and 45 decibels at night, while industrial zones permit 70 decibels during daytime and 60 decibels at night. These limits can be measured using a decibel meter or through computer programs and mobile applications. Citizens should inform violators politely about the specific law being violated, and if violations continue after warnings, they can report to Military Police, City Hall, or Metropolitan Civil Guard, with options for anonymous reporting.

A new acoustic quality public policy law has been approved that requires entities to formulate a public policy on acoustic quality. This law provides greater authority to police for addressing noise-related issues and represents a significant regulatory change in how noise is managed in the city.

São Paulo, one of the world's noisiest cities, proposed increasing noise limits for events from 55 to 85 decibels. According to WHO, ideal noise limits should remain at 60 decibels, as exposure above 65 decibels can cause irreversible hearing damage, increase cortisol production, and lead to cardiovascular problems, high blood pressure, weight gain, irritability, and insomnia. The proposal was criticized for being inserted into an unrelated bill about dark kitchens.

In Europe, 113 million citizens are exposed to noise above pollution thresholds. A study of 749 European cities found 48% of inhabitants exposed to above-average noise levels. Paris is Europe's noisiest city, followed by London and Rome. WHO recommends maximum exposure of 53 decibels; Italian law sets daytime limits at 65 decibels and nighttime at 55 decibels. For reference: silence is ~10 decibels, conversation is 40-50 decibels, peak traffic is ~80 decibels, and discos reach 110 decibels. The lethal noise threshold is 185 decibels.

The state of Nuevo León enacted environmental legislation in September 2022 establishing decibel limits: 55 dB daytime and 50 dB nighttime. This law was approved by the state congress and published in the official state newspaper. The legislation includes an exhortation to all 51 municipalities to homologate their local regulations with these standards. Municipalities like Monterrey are developing new regulations specifically for environmental noise inspection. The law recognizes that excessive noise above 70 dB can cause serious health problems including sleep disturbances, mood changes, and long-term health effects.

Italian composer David Monach's 'Fragments of Extinction' project involves gathering ambisonic field recordings from Earth's remaining primary equatorial rainforests. These recordings form the basis for educational sound artworks installed at museums. Beyond demonstrating acoustic niche principles, Monach adds electronically synthesized tones confined to available acoustic and temporal niches in the frequency spectrum, creating a powerful metaphor of one species performing within a composite ecosystem while trying to find balanced harmonic relationships, thereby helping create ecological awareness for repositioning humanity within nature.

Electroacoustic sound artists create music by combining natural acoustic sounds with electronic processing. Reina's performance demonstrates this approach by using field recordings captured with a microphone on a tripod positioned near trees, capturing environmental sounds like grass, wind, and distant vehicles. These acoustic recordings are simultaneously routed into both a Eurorack modular case and a Mengshi Weenie handheld resonator device. The Mengshi Weenie produces ring textures and feedback that can be manipulated and fed back into the field recorder, creating an interactive loop between natural and electronic sound sources. This technique generates parallel sonic spaces that exist alongside traditional listening environments.

Sound artists use field recording and composition to capture and reveal tensions between anthropogenic development, mass tourism, and climate change impacts on natural environments. By documenting sounds associated with environmental transformation—including helicopters, light aircraft, skiing activities, and natural hazards—artists create works that expose the complex relationships between human activity and ecological degradation in sensitive mountain and polar regions.

Art can address environmental issues by examining material culture and ethical implications of artistic choices. Using decommissioned pianos with ivory keys to create new works comments on elephant poaching for ivory, connecting artistic practice to broader ecological and ethical concerns. Site-specific installations incorporate architectural elements that cannot be accurately captured through recording—f-holes cut into gallery walls allow visitors to hear building vibrations and spatial acoustics, creating experiences impossible to document objectively. Functional sculptures like quarter-rest benches made from wooden felt invite audience interaction, transforming gallery spaces into social environments. Urban sound installations can transform familiar sounds through architectural acoustics, with sewer systems creating unexpected reverberation chambers that fundamentally alter recorded sounds. These approaches demonstrate how contemporary art connects to environmental awareness, architectural consciousness, and the limitations of technological documentation in capturing embodied experience.

The Aelia installation includes a soundtrack comprised of field recordings pieced together by the artists. These recordings capture authentic environmental sounds from Central Florida swamps and forests, creating an immersive audio experience that complements the visual elements. The sound design demonstrates how environmental field recordings can be used as artistic material in contemporary installations, transforming natural sounds into curated artistic experiences.