Soundscape revisited

Welcome to this themed issue of JUD, revisiting soundscape, the acoustic equivalent of landscape. In urban design, soundscape is essentially a matter of the right sound in the right place at the right time at the right level, with respect to the intended use of the space. Which sounds are appropriate, and which are not? Which sounds are present, and which are missing? In this view, sound is a natural resource that contributes to quality of life.

It appears that the term ‘soundscape’ was used in a scientific article for the first time in 1969, some 50 year ago. The author was Michael Southworth (1969), a PhD student in city planning at MIT in Boston, today Professor Emeritus of Urban Design and Planning at the University of California, Berkeley, and the North American Associate Editor of JUD. The article was entitled The Sonic Environment of Cities and was based on Southworth’s Master’s Thesis in city planning, which he completed at MIT in 1967.

While Southworth is well known among academics in urban planning and design, few are aware of his soundscape study. On the other hand, most soundscape researchers are familiar with the 1969 article, but few know the author.

Most soundscape researchers associate ‘soundscape’ with the Canadian composer R. Murray Schafer, at Simon Fraser University in Vancouver, who is famous as the founder of the World Soundscape Project. It began with a detailed study of the soundscape of Vancouver in the early 1970s, and continued with studies worldwide throughout the 1980s. One of its major outcomes was the Handbook for Acoustic Ecology (Truax 1999), defining ‘soundscape’ as ‘[a]n environment of sound (or sonic environment) with emphasis on the way it is perceived and understood by the individual, or by a society’.

Although Schafer used the term ‘soundscape’ in writing as early as in 1967 – referring to contemporary music (Schafer 1969) – there is growing evidence that the World Soundscape Project was inspired by Southworth’s 1969 article (Sterne 2015; von Fischer and Touloumi 2018; Radicchi 2019). Thus, soundscape studies are rooted in architecture and urban design.

With the publication of the 1969 article, Southworth felt his exploration of soundscape was complete at the time and never returned to formal research in the field. He was anxious to move on to other areas such as children’s conception and use of the city, the focus of his MIT doctoral dissertation. However, he continued to be interested in soundscape studies and consulted with many international soundscape researchers in the following years (personal communication). For this themed issue, Southworth contributes with reflections on his soundscape study and his use of the term ‘soundscape’. Many researchers have recently queried about their origins.

Few other scientists took up the subject, which was chiefly left to philosophical and artistic explorations for almost 30 years. Soundscape research gained international momentum when the topic was introduced to the wider community of researchers in noise and health at the International Congresses on Acoustics in Seattle 1998.

The recognition of soundscape among noise and health researchers coincided with the development of noise abatement in the 1990s. This period saw the development of computer-aided noise mapping, as well as the development of the European Environmental Noise Directive (EC 2002) – which is based on noise mapping – and the development of the World Health Organization’s Guidelines for Community Noise (WHO 1999).

The fundamental principle of noise abatement is that society must protect citizens from exposure to harmful levels of noise pollution. To this end, it is necessary to identify what levels of noise pollution are harmful, and to develop noise guidelines. If guideline values are exceeded, society must act to reduce exposure (see EEA 2020 for the current state of noise abatement in Europe).

Computer-aided noise maps were developed to monitor the spatial distribution of noise pollution with regards to sound levels. To make this efficient, these noise maps are based on mathematical models predicting the sound levels as a function of well-known sound sources. At present these sources are limited to road, rail and air traffic, as well as industry. The models are implemented in a Geographical Information System, considering the landscape, including its topology and buildings.

A side effect of noise maps is that an area located far away from surrounding sound sources appears as a white spot on the map. This is an area for which the sound levels from traffic and industry cannot be calculated. This phenomenon gave rise to the concept of ‘quiet areas’ introduced in the European Environmental Noise Directive. The idea is that competent authorities may decide to protect designated ‘quiet areas’ from deterioration. This represents a kind of relief from an otherwise negative mindset with regards to sound in society, which permeates current legislation.

In practice, noise abatement is a reactive approach to sound. First, a member of the public must submit a complaint to the competent authority, which must verify that the complaint is valid and may then take actions. It is a common view among noise and health inspectors that they have no mandate to act, unless there is a complaint, the validity of which is verified. This makes noise abatement comparable to waste management. Sound is deemed a harmful waste product of human activity that must be removed.

Noise maps are used to identify the number of people in a population exposed to excessive sound levels from traffic and industry. The aim is to reduce this number. Typical actions to this end are to place higher demands on manufacturers to make vehicles quieter, or to reduce the transmission of sound from the source to the receiver. In the latter case, it is possible to use a combination of, for example, quiet asphalt, noise barriers or façade insulation in dwellings.

Sound level from traffic is a combination of the sound levels that individual vehicles produce, their speed and the number of vehicles. While manufacturers have reduced the sound levels that individual vehicles produce, this gain in technological development has been consumed by the increase in the number of vehicles on our streets. The latter is a consequence of urbanization, population growth and economic prosperity in society (EC 2011; WHO 2011). The result is an ever-growing number of people exposed to excessive sound levels from traffic as more people live in our cities, affording a car. For Europe, the European Environment Agency forecasts that this negative trend will continue (EEA 2020).

In working with the development of noise abatement in the 1990s, some noise and health researchers realized that it is necessary to develop a holistic approach to the quality of the acoustic environment. The framework for noise abatement is insufficient. Besides being reactive, it focuses only on the negative aspects of sound. The convenient reliance on noise maps means that the management of the acoustic environment is limited to a few negative sound sources, a fraction of all relevant sounds. Surely, there are positive sounds that improve the acoustic environment, sounds that must be promoted. To this group of noise and health researchers, the concept of ‘soundscape’ was a source of inspiration, representing the desired holistic view on the acoustic environment.

In 2008, the International Organization for Standardization (ISO) formed a working group to develop the first international standard dedicated to soundscape, ISO 12913. Part 1 of the standard was published in August 2014. It defines the term ‘soundscape’ as ‘acoustic environment as perceived or experienced and/or understood by a person or people, in context’ (ISO 2014). It also provides a conceptual framework, distinguishing the acoustic environment – as a physical phenomenon – from the soundscape – as a perceptual construct. The definition was inspired by the World Soundscape Project, and by the European Landscape Convention (Council of Europe 2000) that defines ‘landscape’ in similar terms.

In exploring the potential of soundscape, an increasing number of soundscape researchers realize that noise abatement must be complemented with a creative and proactive framework, addressing soundscape early at the planning and design stage. Thus, we are returning to the roots of the field. Fortunately, there is a growing number of young scholars in architecture and urban planning who take an interest in soundscape. A major challenge is to develop the necessary tools for architects and planners to implement soundscape in their practice. This is well reflected in this themed issue.

Clua, Llorca-Bofí and Psarra investigated optimal conditions for introducing the vibrant sound of street busking in the historical centre of Barcelona in Spain, related to acoustical properties, flow of pedestrians and the audience’s field of view. They conclude that there are chiefly two kinds of ideal busking spaces: Streets with a high through-movement are most appropriate for spontaneous street music performance, whereas a plaza that may host a larger audience is more appropriate for organized musical events. The best spots for busking are located within a 40 m radius from a visually integrated street corner.

Xing and Brimblecombe investigated how to improve environmental quality in urban parks in Hong Kong in terms of air and sound. They conclude that solid barriers such as walls, buildings or earth berms can be used to reduce air pollution and sound levels from surrounding streets. A dense belt of conifers on the edge of a park may also trap air pollution and lower the concentrations in the interior of a park. However, the latter is less effective in reducing the sound levels, and any kind of barrier may reduce the visibility from the streets. The size of the park is important, because both sound levels and air pollution decline rapidly with the distance to the surrounding streets. Street design must also be considered. In particular, bus stops and pedestrian crossings should be located at the downstream corner of parks to reduce air pollution and sound levels from idle engines and acceleration, respectively.

Cerwén reports on an autoethnographic study in which he elaborates his previous set of 23 Soundscape Actions for landscape architecture and urban design. For this study, he visited 88 traditional gardens in Japan where he found inspiration for another 10 actions to add to his previous set. The actions are organized in three categories related to where to locate a function – like a garden, how to reduce unwanted and how to introduce wanted sounds. The 10 new actions mainly fall in the last category.

Margaritis, Kang, Aletta and Axelsson took a city-wide approach and investigated the potential relationship between soundscape and urban form in Sheffield, England. They argue that the urban form distributes the sound sources in the city, which in turn create the soundscape. Where there is a street, one would reasonably hear road traffic. In a park, away from the streets, the calm sound of nature would probably dominate, whereas in the busy city centre one would hear the vibrant sound of people. This relationship could be utilized to create soundscape maps, based on the urban form, as a complement to noise maps.

Steele, Kerrigan and Guastavino report on two workshops designed to bring knowledge in soundscape research to practice, utilizing the concept of ‘knowledge mobilization’. The workshops were organized within a transdisciplinary, cross-sector collaboration, named Sounds in the City, between soundscape researchers at McGill University, acoustic consultants, and the City of Montreal. The target audience was professionals including urban designers, planners, architects, sound professionals, and city officials. A diversity of stakeholders proved important to the success of the workshops. It allowed different points of view to be considered that could otherwise easily be overlooked. The participants particularly appreciated interactive as well as immersive soundscape activities, such as soundwalks. The workshops revealed that practitioners perceive academic research as having high credibility but lacking transferability to practical problems. Through the interactive activities, this issue could be addressed. Moreover, it was found that hypothetical scenarios elicit more creative solutions because they provide few practical restrictions. This confirms that sound planning must be incorporated early in the planning process before practical constraints, arising in design and production phases, prevent proactive discussions about soundscape. The workshops also highlighted the importance of visual aids and demonstrations, which go beyond measurements in decibels. They make sound planning more tangible. Although workshops might not result in major new solutions, they are important for building confidence, relationships and a common understanding.

Surely, the reader will find inspiration from these studies for further applied research with the aim of improving the quality of the acoustic environment in our cities for improved health, well-being and quality of life. Please, join us in this endeavour.

Disclosure statement

No potential conflict of interest was reported by the author.