Dimensions underlying the perceived similarities of acoustic environments

Scientific research on how people perceive or experience and/or understand the acoustic environment as a whole (i.e., soundscape) is still in development. In order to predict how people would perceive an acoustic environment, it is central to identify its underlying acoustic properties. This was the purpose of the present study. Three successive experiments were conducted. With the aid of 30 university students, the first experiment mapped the underlying dimensions of perceived similarity among 50 acoustic environments, using a visual sorting task of their spectrograms. Three dimensions were identified: (1) Distinguishable–Indistinguishable sound sources, (2) Background–Foreground sounds, and (3) Intrusive–Smooth sound sources. The second experiment was aimed to validate the results from Experiment 1 by a listening experiment. However, a majority of the 10 expert listeners involved in Experiment 2 used a qualitatively different approach than the 30 university students in Experiment 1. A third experiment was conducted in which 10 more expert listeners performed the same task as per Experiment 2, with spliced audio signals. Nevertheless, Experiment 3 provided a statistically significantly worse result than Experiment 2. These results suggest that information about the meaning of the recorded sounds could be retrieved in the spectrograms, and that the meaning of the sounds may be captured with the aid of holistic features of the acoustic environment, but such features are still unexplored and further in-depth research is needed in this field

What is a soundscape intervention? Exploring definitions and identification criteria and a platform to gather real-world examples

Possible definitions for the concept of “soundscape intervention” and criteria that could be used to identify stages in a design-oriented framework are discussed. This is in line with the Part 4 of the ISO 12913 series on soundscape being currently developed. For some time already, the soundscape concept has attracted attention from policymakers and practitioners of the built environment, as it advocates for more engagement with local communities in design processes. This is reflected in several documents published by national and international agencies calling for consultation and participation of the public in the definition of soundscape interventions. However, this intended framework is still trying to bridge a gap with the planning and design community, possibly for the lack of conspicuous empirical evidence (i.e., case studies and success stories) showing the benefits provided by the soundscape approach, and some lack of consensus about what a “soundscape intervention” is in the first place. Therefore, an online platform will be presented that can be used for data collection of soundscape intervention examples. This relates to the preliminary stage of a project called “Catalogue of Soundscape Interventions (CSI)”, which has the long-term goal of observing frequent/recurring situations or strategies that can be collated into design toolkits and formulate design briefs that local authorities will be using to communicate with soundscape consultants

Factors influencing the sound preference in urban open spaces

In this paper, based on a large scale survey in Europe and China as well as corresponding laboratory studies, the influencing factors on the sound preference evaluation, considering social, demographical, physical, behavioural and psychological facets, have been systematically examined based on statistical analyses for each of the 19 case study sites. Various sound types have been considered, including natural, human, mechanical and instrumental sounds. In terms of social/demographical factors, the results suggest that age and education level are two factors which universally influence the sound preference significantly, although the influence may vary with different types of urban open spaces and sounds. With increasing age or education level, people tend to prefer natural sounds and are more annoyed by mechanical sounds in general. It has also been found that gender, occupation and residence status generally would not influence the sound preference evaluation significantly, although gender has a rather strong influence for certain sound types such as bird sounds, especially at certain case study sites. In terms of physical factors (season, time of day), behavioural factors (frequency of coming to the site, reason for coming to the site), and psychological factors (site preference), generally speaking, their influence on the sound preference evaluation is insignificant, except for limited case study sites and certain sound types. The influence of home sound environment, in terms of sounds heard at home, on the sound preference has been found to be generally insignificant, except for certain sounds. It is noted that there are some correlations between social/demographical factors and the studied physical/behavioural/psychological factors, which should be taken into account when considering the influence of individual factors on sound preference. (C) 2010 Elsevier Ltd. All rights reserved

Ten questions on the soundscapes of the built environment

Soundscape research represents a paradigm shift from noise control policies towards a new multidisciplinary approach as it involves not only physical measurements but also the cooperation of humanity and social sciences to account for the diversity of soundscapes across countries and cultures, with more focus on how people actually experience the acoustic environments; and it considers environmental sounds as a ‘resource’ rather than a ‘waste’. The ten questions presented in this paper range from the very basic definitions underlying the emerging soundscape ‘science’, to more applied topics about how to use soundscape as a design approach for the planning and management of the built environments. Although significant research activity has been conducted so far, there is still a need to systematically provide the underpinning science and practical guidance in soundscaping. Thus, the last question aims to identify the most crucial gaps in soundscape research and set the agenda for future advancements in the field

A framework for improving urban soundscapes

Sound in public urban spaces is often considered in negative terms as both intrusive and undesirable - its referred to as noise! However, this issue is multi-facetted and goes much deeper than simply reducing levels. There are many positive aspects of a soundscape. In an attempt to progress thinking on positive soundscapes and move towards more practical planning approaches and decision making tools for soundscape assessment, this paper proposes an approach traditionally used in product development and manufacturing quality - The Kano Model. The approach is captured in the form of a broader framework which covers: the composition of a soundscape in objective terms; the factors affecting whether it might be perceived as positive; and how the Kano model for product development can be used as a means of understanding the range of applicability of approaches to create positive soundscapes (including several novel approaches which are the subject of other papers in this issue). It can be considered to be complementary with previous frameworks, some of which have concentrated on sound sources, others on the factors affecting perception or even as a model for understanding individual evaluation. In this case the motivation behind the framework is to help assess the likely impact of practical interventions on the positive aspects of a soundscape. The framework proposes that the meaning of "positive" for a public space is quite different for three types of people, each with a different level of direct engagement with the soundscape: planners; serious listeners; users of the space. The first two are influenced by the soundscape itself, either in meeting legislation and reducing nuisance, or as an artistic or creative opportunity. However the third, arguably most important group of people, users of the space, are more concerned with the space itself and have their perception of it influenced by the soundscape, which is an inconvenient and highly complex intermediate step. This influence is largely determined by their activity e.g. reading, holding a conversation, shopping or sightseeing. The paper discusses the further implementation of the framework, and how barriers to the wider application of the concept of positive soundscapes might be overcome. It shows how adapting an approach previously used in automotive sound quality can be adapted for urban soundscapes. It concludes with recommendations for taking the framework forward as a practical approach

The development and application of the emotional dimensions of a soundscape

People have emotional reactions to the built environment, and the sonic environment is one of the major contributing factors of people’s experiences of places. It is useful for decision makers such as planners, architects, engineers and designers to understand the link between the soundscapes of built environments, and their resultant emotional reactions within users of those environments. This understanding can allow these decision makers to make better informed decisions about built environment design, and achieve the desired positive emotional responses from users. The issue under question, and the subject of this paper, was to understand and define the emotional dimensions of a soundscape, and then to explore how the resultant dimensional space could have a practical application in decision making. Through data generated through the Positive Soundscapes Project, a Principal Component Analysis was conducted to decompose descriptors of the urban soundscape into two independent emotional dimensions. It was found that the two independent emotional dimensions of a soundscape relate to its “Calmness” and “Vibrancy”, and these could be positioned to describe a 2-Dimensional (2-D) perceptual space. Listening evaluations were then conducted to explore how perceptions of different types of urban soundscape could be plotted with the 2D emotional perceptual space, and to illustrate how (i) introducing design interventions can change the position of soundscapes within this space and (ii) how metrics such as dB(A) do not necessarily correlate with calmness and vibrancy scores. Through illustrative examples, we suggest how such a 2-D perceptual space might have a practical use in the planning process, primarily as a means for presenting users’ perceptions of soundscapes in a simple, visual, and easy to compare manner, and for setting targets for current and future soundscape design. We conclude with recommendations for further work required to fully develop these emotional dimensions and the 2-D perceptual space into a useful tool

Soundscape descriptors and a conceptual framework for developing predictive soundscape models

Soundscape exists through human perception of the acoustic environment. This paper investigates how soundscape currently is assessed and measured. It reviews and analyzes the main soundscape descriptors in the soundscape literature, and provides a conceptual framework for developing predictive models in soundscape studies. A predictive soundscape model provides a means of predicting the value of a soundscape descriptor, and the blueprint for how to design soundscape. It is the key for implementing the soundscape approach in urban planning and design. The challenge is to select the appropriate soundscape descriptor and to identify its predictors. The majority of available soundscape descriptors are converging towards a 2-dimensional soundscape model of perceived affective quality (e.g., Pleasantness–Eventfulness, or Calmness–Vibrancy). A third potential dimension is the appropriateness of a soundscape to a place. This dimensions provides complementary information beyond the perceived affective quality. However, it depends largely on context, and because a soundscape may be appropriate to a place although it is poor, this descriptor must probably not be used on its own. With regards to predictors, or soundscape indicators, perceived properties of the acoustic environment (e.g., perceived sound sources) are winning over established acoustic and psychoacoustic metrics. To move this area forward it is necessary that the international soundscape community comes together and agrees on relevant soundscape descriptors. This includes to agree on numerical scales and assessment procedures, as well as to standardize them

Perception of soundscapes : an interdisciplinary approach

This paper takes an overall view of findings from the Positive Soundscape Project, a large inter-disciplinary soundscapes study. Qualitative fieldwork (soundwalks and focus groups) have found that soundscape perception is influenced by cognitive effects such as the meaning of a soundscape and its components, and how information is conveyed by a soundscape, for example on the behaviour of people within the soundscape. Three significant clusters were found in the language people use to describe soundscapes: sound sources, sound descriptors and soundscape descriptors. Results from listening tests and soundwalks have been integrated to show that the two principal dimensions of soundscape emotional response seem to be calmness and vibrancy. Further, vibrancy seems to have two aspects: organisation of sounds and changes over time. The possible application of the results to soundscape assessment and design are briefly discussed