Audio Cartography: Visual Encoding of Acoustic Parameters

Our sonic environment is the matter of subject in multiple domains which developed individual means of its description. As a result, it lacks an established visual language through which knowledge can be connected and insights shared. We provide a visual communication framework for the systematic and coherent documentation of sound in large-scale environments. This consists of visual encodings and mappings of acoustic parameters into distinct graphic variables that present plausible solutions for the visualization of sound. These candidate encodings are assembled into an application-independent, multifunctional, and extensible design guide. We apply the guidelines and show example maps that acts as a basis for the exploration of audio cartography

Proposing a conceptual framework to develop the hospital soundscape through visual communication

Sound level measurement is used to assess sound within any environment, never more so than in hospitals. This is due to the negative effects that high sound level can have on patients and staff. However, other ways of exploring sound and the soundscape within the hospital context have been used: sound art has conveyed the experiences of heart transplant patients. Art may act as juxtaposition to objective sound level measurement but the two fundamentally attempt to depict attributes of the soundscape. Using theory from design and concepts from art a framework is presented for designing a positive soundscape experience. This is not through the addition of sound per se but through creatively communicating the information contained within a soundscape to enable the everyday listener to interpret a cacophony of hospital sounds more positively. In representing visual communication of sound as a design object, a new way to explore sound may exist

Towards soundscape fingerprinting: development, analysis and assessment of underlying acoustic dimensions to describe acoustic environments

Soundscape according to the definition in ISO 12913-1 describes an acoustic environment as perceived by humans in context. In order to be able to assess a soundscape holistically, the components acoustic environment, person and context should be described sufficiently to enable triangulation. Person-based soundscape assessment has been the subject of extensive research over the past decades to date, leading to a good understanding of the main emotional dimensions. On the acoustic side, e.g., in modeling emotional responses by acoustic features, parameters describing loudness are widely used, also from the point of view of legal regulations. These parameters are often complemented by established psychoacoustic measures. However, it is unknown to what extent these parameters are suitable to adequately describe and compare acoustic environments for hypotheses concerning humans. The presented dissertation aims to contribute to this field by means of an exploratory, empirical, and data-based approach. First, the general requirements of the aim – the description of acoustic environments – are defined and accompanied with concepts and findings from current research areas. Subsequently a methodology is developed that allows for the identification of underlying acoustic dimensions on the basis of empirical observational data of real world acoustic environments by means of multivariate statistical methods. It contains considerations on the physical sound field, the human auditory system, as well as appropriate signal processing techniques. The methodology is then applied to an exemplary extensive dataset of various Ambisonics soundscape recordings. The resulting expressions of the acoustic dimensions are evaluated and discussed with respect to plausibility and perceptual consistency. Finally, two application examples are presented to further validate the methodology and to test the applicability of acoustic dimensions in concrete research scenarios. It was found that the presented methodology is suitable to identify dimensions for the description of acoustic environments. Furthermore, the dimensions found form a suitable basis for further soundscape analyses.Soundscape (nach ISO 12913-1) beschreibt eine akustische Umgebung, wie sie von Menschen im Kontext wahrgenommen wird. Eine ganzheitliche Beurteilung einer Soundscape wird demnach durch Triangulation der Aspekte akustische Umgebung, Person und Kontext hergestellt. Die personenbezogene Bewertung von Soundscapes war und ist bis heute Gegenstand umfangreicher Forschungsarbeiten, die zu einem weitreichendem Verständnis der wichtigsten emotionalen Dimensionen geführt haben. Auf der akustischen Seite sind Parameter weit verbreitet, die die Lautstärke beschreiben. Ergänzt werden diese Parameter oft durch etablierte psychoakustische Größen. Unbekannt ist jedoch, inwieweit diese (psycho-)akustischen Parameter tatsächlich geeignet sind, Soundscapes zu beschreiben und zu vergleichen hinsichtlich den Menschen betreffender Hypothesen. Hierzu soll diese Dissertation einen Beitrag leisten. Der dabei verfolgte Ansatz ist explorativ, empirisch und datenbasiert. Zunächst werden Anforderungen an das Ziel – die Beschreibung akustischer Umgebungen – definiert und mit Konzepten aus aktuellen Forschungsgebieten ergänzt. Anschließend wird eine Methodik entwickelt, die es erlaubt, fundamentale akustische Dimensionen zu identifizieren auf der Basis empirischer Beobachtungsdaten realer akustischer Umgebungen und mit Hilfe multivariater statistischer Methoden. Sie enthält Überlegungen zum physikalischen Schallfeld, zur menschlichen Hörwahrnehmung sowie zu geeigneten Signalverarbeitungstechniken. Die Methodik wird anschließend auf einen beispielhaften Datensatz von Ambisonics Soundscape-Aufnahmen angewandt. Die resultierenden akustischen Dimensionen werden hinsichtlich ihrer Plausibilität und wahrnehmungsbezogenen Konsistenz diskutiert. Schließlich werden zwei Anwendungsbeispiele vorgestellt, um die Methodik weiter zu validieren und um die Anwendbarkeit der akustischen Dimensionen in konkreten Forschungsszenarien zu testen. Hierbei kann festgestellt werden, dass die gefundenen Dimensionen einen hohen Grad an Varianz akustischer Umgebungen erklären können und gut interpretierbar sind. Sie bilden somit eine geeignete Grundlage für die hier dargestellte Analyse von Soundscapes. Die Methodik ist dabei variabel erweiterbar, sodass vielfältige Anwendungen und Forschungsarbeiten bzgl. akustischer Umgebungen ermöglicht werden

Predictive Modelling of Complex Urban Soundscapes: Enabling an engineering approach to soundscape design

Conventional noise control methods typically limit their focus to the reduction of unwanted noise, ignoring the benets of positive sounds and struggling to reflect the totality of noise impacts. Modern approaches to achieve improved health outcomes and public satisfaction aim to incorporate the perception of an acoustic environment, an approach known as ‘soundscape’. When attempting to apply soundscape in practice, it is apparent that new methods of analysing soundscape perception in urban spaces are required; in particular, a predictive model of the users’ perceptual response to the acoustic environment is necessary. This thesis is intended to enable a move towards applying engineering approaches to soundscape design. This is achieved by developing predictive models of soundscape perception through empirical studies examining a large scale soundscape assessment database. The results are presented in three parts: first, the data collection protocol and modelling methods developed for this work are presented; the second part demonstrates an initial development and application of a predictive soundscape model; the final section expands upon this initial model with two empirical studies exploring the potential for additional information to be included in the model. This thesis begins by establishing a protocol for large scale soundscape data collection based on ISO 12913-2 and the creation of a database containing 1,318 responses paired with 693 binaural recordings collected in 13 locations in London and Venice. The first study then presents an initial development and application of a model designed to predict soundscape perception based on psychoacoustic analysis of the binaural recordings. Through the collection of an additional 571 binaural recordings during the COVID-19 lockdowns, sound level reductions at every location are seen, ranging from a reduction of 1.27 dB(A) in Regents Park Japan to 17.33 dB(A) in Piazza SanMarco, with an average reduction across all locations of 7.27 dB(A). Multi-level models were developed to predict the overall soundscape pleasantness (R2 = 0.85) and eventfulness (R2 = 0.715) of each location and applied to the lockdown recordings to determine how the soundscape perception likely changed. The results demonstrated that perception shifted toward less eventful soundscapes and to more pleasant soundscapes for previously traffic-dominated locations but not for human- and natural-dominated locations. The modelling process also demonstrated that contextual information was important for predicting pleasantness but not for predicting eventfulness. The next stage of the thesis considers a series of expansions to the initial model. The second piece of empirical work makes use of a dataset of recordings collected from a Wireless Acoustic Sensor Network (WASN) which includes sound source labels and annoyance ratings collected from 100 participants in an online listening study. A multilevel model was constructed using a combination of psychoacoustic metrics and sound source labels to predict perceived annoyance, achieving an R2 of 0.64 for predicting individual responses. The sound source information is demonstrated to be a crucial factor, as the relationship between roughness, impulsiveness, and tonality and the predicted annoyance varies as a function of the sound source label. The third piece of empirical work uses multilevel models to examine the extent to which personal factors influence soundscape perception. The findings suggest that personal factors, including psychological wellbeing, age, gender, and occupational status, account for approximately 1.4% of the variance for pleasantness and 3.9% for eventfulness, while the influence of the locations accounted for approximately 34% and 14%, respectively. Drawing from the experience gained working with urban soundscape data, a new method of analysing and presenting the soundscape perception of urban spaces is developed. This method inherently considers the variety of perceptions within a group and provides an open-source visualisation tool to facilitate a nuanced approach to soundscape assessment and design. Based on this empirical evidence, a framework is established for developing future predictive soundscape models which can be integrated into an engineering approach. At each stage, the results of these studies is discussed in terms of how it can contribute to a generalisable predictive soundscape model

Passive acoustic monitoring for assessment of natural and anthropogenic sound sources in the marine environment using automatic recognition

In the marine environment, sound can be an efficient source of information. Indeed, several marine species, including fish, use sound to navigate, select habitats, detect predators and prey, and to attract mates. Therefore, all the abiotic, biotic and manmade sounds that comprise the soundscape, have the potential to be used to assess and monitor species and marine environments. Passive acoustic monitoring (PAM) involves the use of acoustic sensors to record sound in the environment, from which relevant ecological information can be inferred. This thesis studied marine soundscapes, with special attention on fish communities, anthropogenic noise, and applied several methods to analyse acoustic recordings. Most of the focus was on the Tagus estuary, where the presence of two highly vocal species is known: the Lusitanian toadfish (Halobatrachus didactylus) and the meagre (Argyrosomus regius). Azorean and Mozambique soundscapes were also analysed. Several methods were applied to extract information and to visualize soundscape characteristics, including sound recognition systems based on hidden Markov models to recognize fish sounds and boat passages. Analysis of several types of marine environments and time scales showed several advantages and disadvantages of different methods. The use of sound pressure level on different frequency bands allowed the quantification of daily and seasonal patterns. Ecoacoustic indices appear to be cost-effective tools to monitor biodiversity in some marine environments. Using automatic recognition, vocal rhythms (diel and seasonal patterns) and vocal interactions among individuals were also characterized. Furthermore, boat noise effects on fish were studied: we encountered impacts on the audition, vocal behaviour and reproduction. Overall, we used PAM as a tool to remotely assess and monitor soundscapes, biodiversity, fish communities’ seasonal patterns, fish behaviour, species presence, and the effect of anthropogenic noise aiming to contribute for the management and conservation of marine ecosystems

Noise Music, Environment and Peripheral Patterns

The development of the project Peripheral Patterns aims toward an autonomous software system for generative music, that takes as a point of departure, how sound is implicated in our experience of the everyday world in the city. This investigation began with the analysis and consideration of the contrasting soundscapes of the city and the natural settings. The analysis was found to show some correlation with the arrangement and frequencies of sounds in soundscapes and post-industrial noise music works. The above observations led me to the further analysis of soundscapes and noise music. My position on the current city soundscape is as follows: As the human is both a creature from the natural and urban environments, these contrasting vistas will create modern sonic topographies which are exhibited in noise music. Peripheral Patterns explores these convergent spaces to investigate the potential of the sound that is at the limits of human hearing. Whereas once animals occupied small spectral niches in the soundfield, a sky train can be heard passing over Commercial Drive as the constant white noise roars from the city. Conversely, there is a desire for something that resembles peace, a desire to return to an experience of natural soundscape. This thesis looks at a possible convergence of urban and natural soundscapes

INDICES AND ECOINFORMATICS TOOLS FOR THE STUDY OF SOUNDSCAPE DYNAMICS

The study of the new field of soundscape ecology presents several research avenues to explore. In the chapters in this dissertation, I have followed several of the technical and methodological areas of the study of soundscapes. In Chapter 1, I presented the current status of the study of soundscapes as well as an overview of the contributions made in this dissertation to the field. These contributions were framed in the definition of ecological informatics (Michener and Jones 2012). In Chapter 2, I developed a web-based system to manage audio archives. This system organizes thousands of audio files while collecting the necessary metadata

Soundscape Composition: Music as Environmental Activism

Soundscape composition is an emerging genre of experimental music that incorporates sounds from natural environments. While soundscape composers utilize a wide variety of mediums, techniques, and performance contexts, they share a common purpose of encouraging audiences to question and reflect on their relationship to the environment in the age of the “Anthropocene,” enabling listeners to re-connect to the places in which they live through sound. This study asks how soundscape composers use their music as a rhetoric that communicates environmental issues in ways that depart from typical portrayals in mainstream media. Drawing from the works, interviews, and writings of a selected group of soundscape composers, I argue that soundscape composers act as cultural interlocutors, transferring personal and scientific knowledge to a medium that engages alternative ways of environmental knowing. By repurposing scientific technology to serve artistic ends and interrogating conventional Western notions of what counts as “music,” soundscape composers both broaden what counts as environmental knowledge and question conceptual divisions between humans, nature, and technology. By acting upon the potential of soundscape composition to promote social, political, and cultural change, the artists profiled in this study contribute to an understanding of the environmental crisis not only as a physical reality, but as a crisis of character and culture that forces individuals and societies to reconsider how people relate to nature and to each other

Multilevel annoyance modelling of short environmental sound recordings

The recent development and deployment of Wireless Acoustic Sensor Networks (WASN) present new ways to address urban acoustic challenges in a smart city context. A focus on improving quality of life forms the core of smart-city design paradigms and cannot be limited to simply measuring objective environmental factors, but should also consider the perceptual, psychological and health impacts on citizens. This study therefore makes use of short (1–2.7 s) recordings sourced from a WASN in Milan which were grouped into various environmental sound source types and given an annoyance rating via an online survey with N = 100 participants. A multilevel psychoacoustic model was found to achieve an overall R = 0.64 which incorporates Sharpness as a fixed effect regardless of the sound source type and Roughness, Impulsiveness and Tonality as random effects whose coefficients vary depending on the sound source. These results present a promising step toward implementing an on-sensor annoyance model which incorporates psychoacoustic features and sound source type, and is ultimately not dependent on sound level.