Sound in Udmurt Rituals

This article is dedicated to the Udmurt’s understanding of the world of sounds, their norms of behaviour towards sound in the acoustic community. The Udmurt sound worldview has been formed under the influence of the surrounding landscape. The peculiar sound of the Forest, that the Udmurt see and hear in their particular way, causes a particular sound reaction and musical approach. According to tradition, the voice of a singing person must fit into the natural soundscape in order to respect acoustic balance. Within the hunting and fishing cults, singing has received the particular function of a magic incantation. The texts of incantatory songs in hunting and in honey producing, are characterised by incantation formulas as well as by different kinds of sound imitations. The collective community ritual singing is one of the most important elements that organise the Udmurt’s soundscape. The acoustic code is integrated in a whole system of ritual practices; it sanctifies the surrounding cultural and natural landscape. The spring-summer half of the year is characterised by a particularly strong intensity of sounds, as in the most significant calendar holiday, the beginning of the agricultural year, Akashka / Byddzh’ym nunal. The rituals of welcoming have their own aesthetics of sound behaviour. According to the Udmurt community’s mentality, the voice of the singing person is not supposed to stand out of the general sound field. Everywhere, the skilful singer occupies a peculiar position on the Udmurt society: they are valued and respected. At the same time, the belief according to which those who are able to sing well are deeply unhappy in life is very widespread. Taking into account that human voice and singing, in the representations of the Udmurt, possessed a huge force and influence on the surrounding world, we may infer that the singer (the skilful singer!) in the ancient society, who mastered this complicated art, had particular authority. It is even possible that at some moments, he/she fulfilled the function of a mediator between the worlds. And similarly to the shaman, the good singer, usto kyrdzh’as’ could not refuse to practice his/her art, this art given him/her by fate. Thus, the Udmurt’s sound worldview is encompassed into an ontological worldview, which sets the rules of behaviour. It requires a proper sound behaviour inside the natural space as well as in the socio-cultural one, and determines the Udmurt’s behaviour not only in their natural environment but also in the urban space.

Characterization of multi-layer porous media in an impedance tube

A porous material is the combination of a solid phase and a fluid phase, with interactions and energy exchanges between phases giving rise to the dissipation of waves traveling through the porous medium. In air, mostly viscous effects and thermal effects are responsible for dissipation, in a way that strongly depends on the pore microstructure. To evaluate the intrinsic properties pertaining to this microstructure, inverse acoustic methods have been used in the past, typically using impedance tubes to observe the way a porous sample interacts with an acoustic field. The impedance tube is a widespread tool in the acoustic community and has proven to be efficient in retrieving, via an inverse method, porous material intrinsic properties such as the porosity or the tortuosity of a sample. In this work, a Bayesian representation of knowledge is taken, where information on a material property is encoded in a probability density function. When multi-layer materials are considered, classical inverse methods become ill-posed and it might become impossible to retrieve exactly each layer's intrinsic properties. This work presents two straightforward improvements that can be used in order to lift this ill-posedness and increase the precision with which material properties are obtained.

Community Bioacoustics: Studying Acoustic Community Structure for Ecological and Conservation Insights

The diversity of animal acoustic signals has evolved due to multiple ecological processes, both biotic and abiotic. At the level of communities of signaling animals, these processes may lead to diverse outcomes, including partitioning of acoustic signals along multiple axes (divergent signal parameters, signaling locations, and timing). Acoustic data provides information on the organization, diversity and dynamics of an acoustic community, and thus enables study of ecological change and turnover in a non-intrusive way. In this review, we lay out how community bioacoustics (the study of acoustic community structure and dynamics), has value in ecological monitoring and conservation of diverse landscapes and taxa. First, we review the concepts of signal space, signal partitioning and their effects on the structure of acoustic communities. Next, we highlight how spatiotemporal ecological change is reflected in acoustic community structure, and the potential this presents in monitoring and conservation. As passive acoustic monitoring gains popularity worldwide, we propose that the analytical framework of community bioacoustics has promise in studying the response of entire suites of species (from insects to large whales) to rapid anthropogenic change.

First person – Sutirtha Lahiri

ABSTRACT First Person is a series of interviews with the first authors of a selection of papers published in Biology Open, helping early-career researchers promote themselves alongside their papers. Sutirtha Lahiri is first author on ‘Convergent acoustic community structure in South Asian dry and wet grassland birds’, published in BiO. Sutirtha is a research assistant in the lab of Dr Anand Krishnan at the Indian Institute of Science Education and Research (IISER) Pune, India, investigating whether biogeographically distinct grasslands display convergent acoustic community structure.

Convergent acoustic community structure in South Asian dry and wet grassland birds

Although the study of bird acoustic communities has great potential in long-term monitoring and conservation, their assembly and dynamics remain poorly understood. Grassland habitats in South Asia comprise distinct biomes with unique avifauna, presenting an opportunity to address how community-level patterns in acoustic signal space arise. Similarity in signal space of different grassland bird assemblages may result from phylogenetic similarity, or because different bird groups partition the acoustic resource, resulting in convergent distributions in signal space. Here, we quantify the composition, signal space and phylogenetic diversity of bird acoustic communities from dry semiarid grasslands of Northwest India and wet floodplain grasslands of Northeast India, two major South Asian grassland biomes. We find that acoustic communities occupying these distinct biomes exhibit convergent, overdispersed distributions in signal space. However, dry grasslands exhibit higher phylogenetic diversity, and the two communities are not phylogenetically similar. The Sylvioidea encompasses half the species in the wet grassland acoustic community, with an expanded signal space compared to the dry grasslands. We therefore hypothesize that different clades colonizing grasslands partition the acoustic resource, resulting in convergent community structure across biomes. Many of these birds are threatened, and acoustic monitoring will support conservation measures in these imperiled, poorly-studied habitats.

"Well, listen ... " : acoustic community on Toronto Island.

"Well, listen. .. "is a sound composition about the acoustic community of Toronto Island and Toronto Harbour. The project explores how people create and experience acoustic community, how perceptions of the soundscape are related to attitudes about nature and culture, and how power relationships are articulated through sound. The project is based in environmental cultural studies and in sound ecology, notably the work of Williams (1973), Schafer (1977), Westerkamp (2002) and Truax (1984), and concludes seven months of soundwalks, interviews, composition, editing and field research. Participants discussed the soundscape of Toronto Island, noise pollution in Toronto Harbour and the relationship between sound, community and ecology. These interviews were edited and re-assembled in a manner inspired by the contrapuntal voice compositions of Glenn Gould. Field recordings reflect the complex mix of natural, social, and industrial sounds that make up the soundscape of the harbour, and document the acts of sound walking and deep listening that are the core methods of soundscape research. The composition creates an imaginary aural space that integrates the voices and reflections of the Island's acoustic community with the contested soundscape of their island home. The project paper outlines the theory and methods that informed the sound composition, and further explores the political economy of noise pollution, especially in relation to the Docks nightclub dispute and to current research in sound ecology.

"Well, listen ... " : acoustic community on Toronto Island.

"Well, listen. .. "is a sound composition about the acoustic community of Toronto Island and Toronto Harbour. The project explores how people create and experience acoustic community, how perceptions of the soundscape are related to attitudes about nature and culture, and how power relationships are articulated through sound. The project is based in environmental cultural studies and in sound ecology, notably the work of Williams (1973), Schafer (1977), Westerkamp (2002) and Truax (1984), and concludes seven months of soundwalks, interviews, composition, editing and field research. Participants discussed the soundscape of Toronto Island, noise pollution in Toronto Harbour and the relationship between sound, community and ecology. These interviews were edited and re-assembled in a manner inspired by the contrapuntal voice compositions of Glenn Gould. Field recordings reflect the complex mix of natural, social, and industrial sounds that make up the soundscape of the harbour, and document the acts of sound walking and deep listening that are the core methods of soundscape research. The composition creates an imaginary aural space that integrates the voices and reflections of the Island's acoustic community with the contested soundscape of their island home. The project paper outlines the theory and methods that informed the sound composition, and further explores the political economy of noise pollution, especially in relation to the Docks nightclub dispute and to current research in sound ecology.

Ecoacoustics and Multispecies Semiosis: Naming, Semantics, Semiotic Characteristics, and Competencies

Biosemiotics to date has focused on the exchange of signals between organisms, in line with bioacoustics; consideration of the wider acoustic environment as a semiotic medium is under-developed. The nascent discipline of ecoacoustics, that investigates the role of environmental sound in ecological processes and dynamics, fills this gap. In this paper we introduce key ecoacoustic terminology and concepts in order to highlight the value of ecoacoustics as a discipline in which to conceptualise and study intra- and interspecies semiosis. We stress the inherently subjective nature of all sensory scapes (vivo-, land-, vibro- and soundscapes) and propose that they should always bear an organismic attribution. Key terms to describe the sources (geophony, biophony, anthropophony, technophony) and scales (sonotopes, soundtopes, sonotones) of soundscapes are described. We introduce epithets for soundscapes to point to the degree to which the global environment is implicated in semiosis (latent, sensed and interpreted soundscapes); terms for describing key ecological structures and processes (acoustic community, acoustic habitat, ecoacoustic events) and examples of ecoacoustic events (choruses and noise) are described. The acoustic eco-field is recognized as the semiotic model that enables soniferous species to intercept core resources like food, safety and roosting places. We note that whilst ecoacoustics to date has focused on the critical task of the development of metrics for application in conservation and biodiversity assessment, these can be enriched by advancing conceptual and theoretical foundations. Finally, the mutual value of integrating ecoacoustic and biosemiotics perspectives is considered.

The Quiet Project – UK Acoustic Community’s response to COVID19 during the easing of lockdown

The COVID-19 lockdown created a new kind of environment both in the UK and globally, never experienced before or likely to occur again. A vital and time-critical working group was formed with the aim of gathering crowd-source high quality baseline noise levels and other supporting information across the UK during the lock-down and subsequent periods. The acoustic community were mobilised through existing networks engaging private companies, public organisations and academics to gather data in accessible places. In addition, pre-existing on-going measurements from major infrastructure projects, airport, and planning applications were gathered to create the largest possible databank. A website was designed and developed to advertise the project, provide instructions and to formalise the uploading of noise data, observations and soundscape feedback. Two case studies gathered in the latter stage of full lockdown are presented in the paper to illustrate the changes in the environmental noise conditions relative to transport activity. Ultimately the databank will be used to establish the relation to other impacts such as air quality, air traffic, economic, and health and wellbeing. As publicly funded research the databank will be made publicly available to assist future research.

Convergent acoustic community structure in South Asian dry and wet grassland birds

Although the study of bird acoustic communities has great potential to provide valuable conservation data, many aspects of their assembly and dynamics remain poorly understood. Grassland habitats in South Asia comprise distinct biomes with a unique avifauna, presenting an opportunity to address how community-level patterns in acoustic signal space arise. Similarity in signal space of different grassland bird communities may be due to phylogenetic similarity, or because different bird groups partition the acoustic resource, resulting in convergent distributions in signal space. Here, we quantify the composition, signal space and phylogenetic diversity of bird acoustic communities from the dry semiarid grasslands of Northwest India and the wet floodplain grasslands of Northeast India. We find that acoustic communities occupying these distinct biomes exhibit convergent signal space. However, dry grasslands exhibit higher phylogenetic diversity, and the two communities are not phylogenetically more similar than expected by chance. The Sylvioidea encompasses half the species in the wet grassland acoustic community, with an expanded signal space compared to the dry grasslands. Thus, dry and wet grassland communities are convergent in signal space despite differences in phylogenetic diversity. We therefore hypothesize that different clades colonizing grasslands partition the acoustic resource, resulting in convergent community structure across biomes. Many of the birds we recorded are highly threatened, and acoustic monitoring will support conservation measures in these imperiled, yet poorly-studied habitats.