Soundscape Mapping Research Articles

Cultural Soundscape Mapping: An Innovative Lesson for STEAM–Multisensory Integrated Education

Cultural Soundscape Mapping: An Innovative Lesson for STEAM–Multisensory Integrated Education

Soundscape mapping: understanding regional spatial and temporal patterns of soundscapes incorporating remotely-sensed predictors and wildfire disturbance

Increased environmental threats require proper monitoring of animal communities to understand where and when changes occur. Ecoacoustic tools that quantify natural acoustic environments use a combination of biophony (animal sound) and geophony (wind, rain, and other natural phenomena) to represent the natural soundscape and, in comparison to anthropophony (technological human sound) can highlight valuable landscapes to both human and animal communities. However, recording these sounds requires intensive deployment of recording devices and storage and interpretation of large amounts of data, resulting in large data gaps across the landscape and periods in which recordings are absent. Interpolating ecoacoustic metrics like biophony, geophony, anthropophony, and acoustic indices can bridge these gaps in observations and provide insight across larger spatial extents and during periods of interest. Here, we use seven ecoacoustic metrics and acoustically-derived bird species richness across a heterogeneous landscape composed of densely urbanized, suburban, rural, protected, and recently burned lands in Sonoma County, California, U.S.A., to explore spatiotemporal patterns in ecoacoustic measurements. Predictive models of ecoacoustic metrics driven by land-use/land-cover, remotely-sensed vegetation structure, anthropogenic impact, climate, geomorphology, and phenology variables capture landscape and daily differences in ecoacoustic patterns with varying performance (avg. R 2 = 0.38 ± 0.11) depending on metric and period-of-day and provide interpretable patterns in sound related to human activity, weather phenomena, and animal activity. We also offer a case study on the use of the data-driven prediction of biophony to capture changes in soniferous species activity before (1–2 years prior) and after (1–2 years post) wildfires in our study area and find that biophony may depict the reorganization of acoustic communities following wildfires. This is demonstrated by an upward trend in activity 1–2 years post-wildfire, particularly in more severely burned areas. Overall, we provide evidence of the importance of climate, spaceborne-lidar-derived forest structure, and phenological time series characteristics when modeling ecoacoustic metrics to upscale site observations and map ecoacoustic biodiversity in areas without prior acoustic data collection. Resulting maps can identify areas of attention where changes in animal communities occur at the edge of human and natural disturbances.

Integrating spatial-temporal soundscape mapping with landscape indicators for effective conservation management and planning of a protected area

Protected areas (PAs) possess generous biodiversity, making them great potential for human and wildlife well-being. Nevertheless, rising anthropogenic sounds may pose a serious challenge and threat to the habitats. Therefore, understanding the acoustic environments of PAs and implementing proper conservation strategies are essential for maintaining species richness within the territory. In this study, we investigate the spatial-temporal variations of soundscape distribution in the Dashanbao Protected Area (DPA) of China, ultimately discussing the planning and management strategies. Firstly, to systematically analyse the spatial-temporal soundscape distribution of the reserve, we generated single and multi-acoustic source maps by classifying geographical, biological, and anthropogenic sounds. In the region, we installed 35 recording points and collected sounds using the synchronic recording method. Secondly, we conducted Spearman correlation analyses to examine the relationships between the sound sources and i) temporal variations, ii) landscape feature indicators. Thirdly, we identified the dominant sound sources in the region and their conflict areas through the cross-analysis module of Grass Geographic Information Systems (GIS). Finally, we provided sound control strategies by discussing landscape indicators and land-use management policies. The results show that even though there is conservation planning in the DPA, anthropogenic sounds dominate in certain parts of the reserve depending on diurnal and seasonal cycles. This reveals deficiencies in the DPA's current planning concerning the soundscape and highlights the effectiveness of spatial-temporal mapping. Additionally, our correlation analyses demonstrate that landscape feature indicators can represent how sound environment is affected by landscape. The patch diversity (PD), landscape shape index (LSI), Shannon's Diversity Index (SHDI), woodland, shrubland, and water distance (WD) were identified as the primary predictors for both biological and anthropogenic sounds. None of the indicators exhibited a significant positive or negative correlation with geological sounds. Consequently, to enhance and conserve the acoustic quality of the region, spatial-temporal mapping with landscape indicators can be employed in the management and planning processes.

Soundscape maps of pleasantness in a university campus by crowd-sourced measurements interpolation

Abstract A university campus is a complex environment, as it comprises many areas, each with distinctive acoustic characteristics. There are zones where a quiet environment is crucial for work and study, parking lots and internal road networks, as well as vibrant spaces where students and personnel stay during leisure time. Thus, university campuses clearly offer a remarkable opportunity for the evaluation of soundscape analysis tools and the exploration of new methodologies for assessing and mapping soundscapes. In this work, the Fisciano campus of the University of Salerno (Italy) has been depicted as a case study. Specifically, the outcomes of a soundwalk conducted following ISO/TS 12913 standards will be presented, together with data gathered through crowd-sourcing during NoiseCapture parties. The data from NoiseCapture parties have been used to test and validate an innovative methodology based on an inverse distance weighting interpolation to produce soundscapes’ attributes maps, using the mean pleasantness as an example and exploring the relative influence of the maximum distance used to characterize an homogeneous sound environment to build the maps themselves. The results will offer valuable insights into the proposed methodology.

How Should Soundscape Optimization from Perceived Soundscape Elements in Urban Forests by the Riverside Be Performed?

Urban forests by the riverside are important habitats for various animals and contribute various soundscapes for citizens. Unfortunately, urban forests are exposed to the influence of riverside traffic noises from freeways. This study aims to explore the spatial and temporal variation of soundscape, conduct soundscape optimization for multiple parameters, and find a balance and its interval of soundscape elements through optimizing a soundscape map. Questionnaires and measuring equipment were used to gather soundscape information in an urban forested area in Fuzhou, China. Diurnal variations and soundscape mapping were used to analyze spatial and psychophysical relationships between soundscape drivers. We then conducted optimization for a soundscape map, which included normalization, critical value determination, target interval of optimal SPL determination, and modification of SPL and mapping. Our findings suggest that biological activities and natural phenomena are potential drivers for diurnal variation of soundscapes, especially tidal phenomena contributing water and shipping soundscapes. Our results also suggest that all the high values of perceived soundscapes were found at the southwest corner of the study area, which includes both riverside and urban forest elements. Furthermore, we suggest combining both optimal soundscape and SPL correction maps to aid in sustainable design in urban forests. This can contribute to the understanding and methodology of soundscape map optimization in urban forests when proposing suitable design plans and conservation of territorial sound.

Sensing urban soundscapes from street view imagery

A healthy acoustic environment is an essential component of sustainable cities. Various noise monitoring and simulation techniques have been developed to measure and evaluate urban sounds. However, sensing large areas at a fine resolution remains a great challenge. Based on machine learning, we introduce a new application of street view imagery — estimating large-area high-resolution urban soundscapes, investigating the premise that we can predict and characterize soundscapes without laborious and expensive noise measurements. First, visual features are extracted from street-level imagery using computer vision. Second, fifteen soundscape indicators are identified and a survey is conducted to gauge them solely from images. Finally, a prediction model is constructed to infer the urban soundscape by modeling the non-linear relationship between them. The results are verified with extensive field surveys. Experiments conducted in Singapore and Shenzhen using half a million images affirm that street view imagery enables us to sense large-scale urban soundscapes with low cost but high accuracy and detail, and provides an alternative means to generate soundscape maps. R2 reaches 0.48 by evaluating the predicted results with field data collection. Further novelties in this domain are revealing the contributing visual elements and spatial laws of soundscapes, underscoring the usability of crowdsourced data, and exposing international patterns in perception.

Developing a Multi-sensory Public Participation GIS (MSPPGIS) method for integrating landscape values and soundscapes of urban green infrastructure

This paper develops, tests and validates a Multi-sensory Public Participation GIS (MSPPGIS) method combining the qualities of soundscapes and landscape values mapping. The development of the method involved: a) Public Participation GIS survey design; b) three-phase evaluation of survey addressing analytical, applicability and usability criteria; c) survey refinement; d) sampling and data collection, and; e) spatial data analysis. The analysis consisted of hotspot mapping involving Kernel Density Estimation, spatial overlap assessment using Jaccard coefficients and value compatibility analysis showing the level of spatial compatibility between positive landscape values and positive and negative soundscapes. Results indicated very low to low spatial overlap between the different landscape values and pleasant/unpleasant sound hotspots, suggesting that landscape values do not necessarily reflect sonic perception of urban green and blue spaces. Pleasant and unpleasant sounds were located closer to home than landscape values (except for urban life values), indicating that respondents’ soundscape ‘cognitive map’ is smaller in spatial range. The MSPPGIS method enables the elicitation of a more dynamic and diverse set of sounds compared to previous soundscape mapping which tend to focus on 'noise' instead of multiple experiences of different sounds. Also, the combination of landscape values and soundscapes in MSPPGIS provides for a more integrated assessment of ‘where’ and ‘how’ to design urban green infrastructure.

Research on spatiotemporal variation characteristics of soundscapes in a newly established suburban forest park

Passive acoustic monitoring has developed rapidly as a tool for ecological assessments, and the use of acoustic indices to assess biodiversity in urban forests promises to be a low-cost and efficient analytical approach. However, the accuracy of using acoustic indices to characterize biodiversity may be compromised by excessive human interference. The acoustic complexity index (ACI) and normalized difference soundscape index (NDSI) were chosen to determine their application value, and explore the spatiotemporal patterns of change in the soundscape of a newly established suburban forest park in China. To understand the influence of drivers such as different sound source types, road distance, and vegetation structure on the soundscape, the Eastern Suburb Forest Park was selected as the study area, and 55 recording points (200 m intervals, 5 × 11 grids) were set up using a systematic grid. Passive acoustic monitoring was performed for four consecutive days in each season, and the spatiotemporal variation of the soundscape was visualized based on indices interpolation. The results showed that when using ACI and NDSI to rapidly assess biodiversity in urban forest environments, attention needs to be paid to the implications of seasonal fluctuations on indices. The temporal variation of the soundscape was closely related to the natural rhythms and vocal activity intensity of organisms. Distance to a nearby main road, distance to water, and structural complexity of vegetation were key factors influencing spatial variation. The findings support the use of acoustic methods to assess the characteristics of soundscapes in human-built urban forests. Soundscape mapping visualizes hotspots and moments of ecoacoustic activity, and has great potential for development in the conservation and management of suburban forest soundscapes.

Spatial and sociodemographic determinants of community loudness perception

Urban noise is an increasingly important public health concern, but few studies have characterized drivers of community loudness perception rather than objective measures of sound, which may be an important element of the associated health effects. In this study, we used survey responses from the 2015–2016 Greater Boston Neighborhood Noise Survey (n = 898) to determine the key geospatial determinants of community loudness perception at both the street and neighborhood level. We gathered numerous land use and sociodemographic covariates and used an elastic net selection approach to determine the subset to include in final prediction models. Individual noise sensitivity and proximity to bus stops (<150 m) was associated with perceived loudness at the street and neighborhood level. In addition, at the street level, the restaurant and transportation infrastructure within close proximity (<200 m) of the residence were predictive of perceived loudness. At the neighborhood level, there was a larger and more complex set of predictors in the final prediction model, including multiple commercial/business sources at larger distances (500–1000 m buffers) from the residence. In general, these predictors overlapped with those in existing models predicting objective sound across multiple frequencies (A-weighted sound. low-frequency sound, mid-frequency sound, and high frequency sound), especially for transportation sources, although some predictors of noise perception differed from those for sound measurements. These results emphasize the importance of characterizing both perceived noise and objective sound, with the combined insights helping to develop soundscape maps and determine which urban areas require intervention to improve community public health.

Large-scale assessment of masking potential by underwater ship noise the North Sea

The JOMOPANS project created one year of soundscape maps of the North Sea, based on ship information from the Automatic Identification System (AIS) and a ship source model. This assessed the potential impact of ship noise on the marine ecosystem through the masking of communication and other relevant acoustic signals. Specifically, the excess noise was quantified, which express the deterioration of the signal-to-noise ratio caused by the ship noise and hence the reduction in maximum communication range. The dominance of ship noise over natural sources was quantified as the percentage of time where excess was 20 dB or higher. A decrease in signal-to-noise ratio of 20 dB compared to a reference condition (ambient plus weather) without ships indicates a substantial decrease in communication range, and hence a substantial risk of impact on the ecosystem. Maps of excess and dominance in different frequency bands showed the largest ship contribution in the lowest frequency bands and in the most trafficked areas, with less affected areas in shallow waters, including the Dogger Bank. These maps, in combination with distribution maps of sensitive species, form the basis for the joint assessment of environmental status of the North Sea by the surrounding countries.

Smartphone-Based Participatory Soundscape Mapping for a More Sustainable Acoustic Environment

The urban environmental planning, a fundamental dynamic process for cities’ sustainability, could benefit from the soundscape approach, dealing with the perception of the acoustic environment in which sound is considered as a resource rather than a waste (noise). Noise and soundscape maps are useful tools for planning mitigation actions and for communication with citizens. Both mappings can benefit from crowdsourcing and participatory sound monitoring that has been made possible due to the large use of internet connections and mobile devices with dedicated apps. This paper is a “scoping review” to provide an overview of the potential, benefits, and drawbacks of participatory noise monitoring in noise and soundscape mapping applications, while also referring to metrological aspects. Gathering perceptual data on soundscapes by using digital questionnaires will likely be more commonly used than printed questionnaires; thus, the main differences between the experimental protocols concern the measurement of acoustic data. The authors propose to classify experimental protocols for in-field soundscape surveys into three types (GUIDE, MONITOR, and SMART) to be selected according to the survey’s objectives and the territorial extension. The main future developments are expected to be related to progress in smartphone hardware and software, to the growth of social networks data analysis, as well as to the implementation of machine learning techniques.

Soundscape mapping for spatial-temporal estimate on bird activities in urban forests

Soundscape mapping provides a unique perspective to explain the complicated spatial-temporal change of bird activities in urban forests. Most studies of soundscapes have used multi-point distribution to record sounds, which is challenging for explaining complex interferences factors in urban areas. In this study, we used soundscape mapping to explore the habitat selection of bird communities in the context of spatial-temporal structural changes. We selected the transition area from city to forest in Shenzhen, China, as the study area, set up 30 recording points which arranged in grid patterns (5 × 6), and used synchronic recording methodology to collect sounds. Aural species identification, power spectral density (PSD), and normalized-difference sound index (NDSI) were used to quantify sounds. Passerine birds (92.11 %) were found to comprise the first acoustic communities. Changes in bird species populations among seasons were noted, with spring having the most abundant bird species number (n = 59) and the most abundant ecoacoustic events. Bird communities with different frequency band clusters having different preferences for vegetation characteristics were detected. A significant two-way interaction between the accessibility of recording points and seasons on bird activities was found in this study. Urban forest spatial structure had a great effect on bird activities, and specifically through the shape of forest vertical structure complexity and forest edge effect. Our study shows the broader application potential of soundscape mapping in urban forest ecosystem research.

Soundscape approach integrating noise mapping in Namsan Promenade

Namsan is a 262 m high mountain located in the center of Seoul. Its easy accessibility and tourist attractions such as a cable car and a tall tower on the top allure native and foreign people. It functions as a park rather than a mountain and has a 7.5 km promenade around it with a moderate slope where even the old and the weak enjoy walking. Some parts of the promenade are surrounded by trees and flowing waters but other parts are influenced by shuttle buses, roundabout road-traffic and various machines etc. Noise maps for the sources were generated to find the spatial distribution of the noise over the mountain including the promenade. By observation along the promenade, natural sound including mainly birdsong and water streaming sound were identified and sound maps were generated. To collect individual responses from 4 acousticians and 6 non-acoustic people about an on-site questionnaire of the sound environment along the promenade, a total of 37 spots were selected apart from each other by approximately 200 m. The responses were used to generate soundscape maps. Separate and combined analyses of the three acoustic maps were performed to propose some measures to improve sound quality of the promenade.

Simplistic underwater ambient noise modelling for shallow coastal areas: Lithuanian area of the Baltic Sea

It is known that underwater sea soundscapes are produced by natural noise sources that occur on the water surface and subsurface water layers. Wind, water splashes, sprays, and breaking waves produce a bubble layer, which in turn produces downward directed sound radiation. There are several additional sources that contribute to underwater noise levels, mainly from commercial shipping, and various anthropogenic sources both out at sea and in coastal areas. Recent research projects have investigated the effects of shipping traffic on the ambient soundscape in the Baltic Sea, stressing the need for long term ambient soundscape monitoring using underwater noise measurements and modelling. Freely available underwater noise models allow for the evaluation of ambient noise levels produced on water surfaces as well, as the creation of soundscape maps. In this manuscript, a simplistic underwater noise model is presented, developed for evaluating and mapping the soundscape in shallow marine areas, and for investigating the noise levels in different seasons.

A model for implementing soundscape maps in smart cities

Abstract Smart cities are required to engage with local communities by promoting a user-centred approach to deal with urban life issues and ultimately enhance people’s quality of life. Soundscape promotes a similar approach, based on individuals’ perception of acoustic environments. This paper aims to establish a model to implement soundscape maps for the monitoring and management of the acoustic environment and to demonstrate its feasibility. The final objective of the model is to generate visual maps related to perceptual attributes (e.g. ‘calm’, ‘pleasant’), starting from audio recordings of everyday acoustic environments. The proposed model relies on three main stages: (1) sound sources recognition and profiling, (2) prediction of the soundscape’s perceptual attributes and (3) implementation of soundscape maps. This research particularly explores the two latter phases, for which a set of sub-processes and methods is proposed and discussed. An accuracy analysiswas performed with satisfactory results: the prediction models of the second stage explained up to the 57.5% of the attributes’ variance; the cross-validation errors of the model were close to zero. These findings show that the proposed model is likely to produce representative maps of an individual’s sonic perception in a given environment.

Soundscape mapping in environmental noise management and urban planning: case studies in two UK cities

Soundscape mapping in environmental noise management and urban planning: case studies in two UK cities

High-performance Sonitopia (Sonic Utopia): Hyper intelligent Material-based Architectural Systems for Acoustic Energy Harvesting

The rate of energy consumption in all over the world, based on reliable statistics of international institutions such as the International Energy Agency (IEA) shows significant increase in energy demand in recent years. Periodical recorded data shows a continuous increasing trend in energy consumption especially in developed countries as well as recently emerged developing economies such as China and India. While air pollution and water contamination as results of high consumption of fossil energy resources might be consider as menace to civic ideals such as livability, conviviality and people-oriented cities. In other hand, automobile dependency, cars oriented design and other noisy activities in urban spaces consider as threats to urban life. Thus contemporary urban design and planning concentrates on rethinking about ecology of sound, reorganizing the soundscape of neighborhoods, redesigning the sonic order of urban space. It seems that contemporary architecture and planning trends through soundscape mapping look for sonitopia (Sonic + Utopia) This paper is to propose some interactive hyper intelligent material-based architectural systems for acoustic energy harvesting. The proposed architectural design system may be result in high-performance architecture and planning strategies for future cities. The ultimate aim of research is to develop a comprehensive system for acoustic energy harvesting which cover the aim of noise reduction as well as being in harmony with architectural design. The research methodology is based on a literature review as well as experimental and quasi-experimental strategies according the paradigm of designedly ways of doing and knowing. While architectural design has solution-focused essence in problem-solving process, the proposed systems had better be hyper intelligent rather than predefined procedures. Therefore, the steps of the inference mechanism of the research include: 1- understanding sonic energy and noise potentials as energy resources, 2- recognition of transductor and other similar mechanisms, 3- developing an integrated, hyper intelligent and material-based system, 4- examining the productivity, performance and efficiency of proposed systems in commercial buildings and office departments of Tehran as case study. The results of the research show that high-performance Sonitopia concept might be helpful for adoption in contemporary architecture of developing countries such as Iran in order to better energy efficiency. It is intelligent energy systems (IES) enjoy electromechanical energy converters based on performance-oriented design in over-crowded architectural spaces. The results indicated significance of concentrating on smart, intelligent and recombinant materials in order to achieve higher performance and productivity.

Exploring spatial relationships among soundscape variables in urban areas: A spatial statistical modelling approach

Noise maps based on sound pressure levels are limited in accurately representing how people perceive the sound environment. As a complementary approach to noise maps, soundscape maps can be useful tools for urban planning and design because they provide more information than conventional noise maps to reflect perceived acoustic environments. This study provides an overview of soundscape maps and explores the influence of spatial contexts on soundscapes in urban spaces. Physical, acoustic, and perceptual data were collected on sound environments in various urban areas in Seoul to create soundscape maps. Sound source types (traffic noise, human sounds, water sounds, and birdsongs), psychoacoustic parameters (loudness and sharpness), and perceived soundscape quality maps were generated and it was found that soundscape characteristics were varied in accordance with the primary functions of a space. Based on the collected soundscape data, global and local spatial regression analyses were conducted to examine the spatial autocorrelation on prediction on soundscape quality, and spatial dependency of soundscape quality was found in both models. In particular, a local spatial regression model based on geographically non-stationary relationships in variables was found to be more effective in understanding soundscape quality in multi-functional urban spaces. These findings could provide useful knowledge for soundscape planning strategies.

BIAS: A Regional Management of Underwater Sound in the Baltic Sea.

Management of the impact of underwater sound is an emerging concern worldwide. Several countries are in the process of implementing regulatory legislations. In Europe, the Marine Strategy Framework Directive was launched in 2008. This framework addresses noise impacts and the recommendation is to deal with it on a regional level. The Baltic Sea is a semienclosed area with nine states bordering the sea. The number of ships is one of the highest in Europe. Furthermore, the number of ships is estimated to double by 2030. Undoubtedly, due to the unbound character of noise, an efficient management of sound in the Baltic Sea must be done on a regional scale. In line with the European Union directive, the Baltic Sea Information on the Acoustic Soundscape (BIAS) project was established to implement Descriptor 11 of the Marine Strategy Framework Directive in the Baltic Sea region. BIAS will develop tools, standards, and methodologies that will allow for cross-border handling of data and results, measure sound in 40 locations for 1 year, establish a seasonal soundscape map by combining measured sound with advanced three-dimensional modeling, and, finally, establish standards for measuring continuous sound. Results from the first phase of BIAS are presented here, with an emphasis on standards and soundscape mapping as well as the challenges related to regional handling.

Soundscape approach integrating noise mapping techniques: a case study in Brighton, UK

AbstractIn the guidelines about the management of areas of good environmental noise quality recently published by the European Environment Agency (EEA) it is suggested to combine different methodologies, like noise mapping, sound level measurements and the soundscape approach. Such a recommendation has started to be recognised by a number of local authorities in Europe that are gradually integrating a holistic concept into their environmental noise policies. This research aimed to explore and demonstrate the possibility to integrate conventional noise mapping methods and soundscape methods in an actual urban redevelopment project. A case study was made using the Valley Gardens project in Brighton &amp; Hove (UK). Different scenarios of sound-pressure level distributionswere simulated for both traffic sound sources (i.e. noise maps) and natural sound sources (i.e. sound maps). Additionally, individual responses about the sound environment of the place collected during an on-site question survey were used to implement soundscape maps.The overall picture revealed that the road traffic noise should be reduced, but also it is feasible that preferred sounds likewater features or birdsong could be introduced to make the sound environment more appropriate for the place. Generally, within the framework of this research, noise maps, sound maps and soundscape maps were used together to "triangulate" different layers of information related to the acoustic environment and the way it is perceived, providing a possible working procedure to consider for planners and policy-makers in the future.