Acoustic Ecology Research Articles

Importance of the receiver's height for transmission studies in acoustic ecology.

In animal communication, the sound pressure level (SPL) of the acoustic signals has been studied in relation to various biological functions. Previous research reported that senders and receivers benefit from being at elevated positions. However, sometimes, researchers find contradictory results. Using a transmission experiment, we measured SPL of two acoustic stimuli: (i) white noise, and (ii) advertisement calls of the Iberian tree frog (Hyla molleri) at two different heights above ground level (0.05 and 0.75 m) and from six distances (1, 2, 4, 8, 16, and 32 m) from a loudspeaker. Calls of the Iberian tree frog have two spectral peaks centred at the frequencies of ca. 1 and 2 kHz. As expected, SPL decreased with distance, but following a distinct attenuation pattern across height above the ground and frequency. Our findings show that the ground effect may critically alter frequency attenuation and, therefore, signal composition and discrimination at the listener's location, even at low heights above the ground. We suggest that recording devices should be positioned at the same height that natural listeners are usually located in nature, to facilitate the replication and comparison of experiments in the field of acoustic ecology and, also, bioacoustics.

Ontogeny of vocalizations in Adélie penguin (Pygoscelis adeliae) chicks from West Antarctica

Acoustic indices are an efficient method for monitoring dense aggregations of vocal animals but require understanding the acoustic ecology of the species under examination. The present understanding of avian behavior and vocal development is primarily derived from the research of songbirds (Passeriformes). However, given that behavior and environment can differ greatly among bird orders, passerine birdsong may be insufficient to define the vocal ontogeny of non-passerine birds. Like many colonial nesting seabirds, the Adélie penguin (Pygoscelis adeliae) is adapted to loud and congested environments with limited cues to identify kinship within aggregations of conspecifics. In addition to physical or geographical cues to identify offspring, adult P. adeliae rely on vocal modulation. Numerous studies have been conducted on mutual vocal modulations in mature P. adeliae, but limited research has explored the vocal repertoire of the chicks and how their vocalizations evolve over time. Using the deep learning-based system, DeepSqueak, this study characterized the vocal ontogeny of P. adeliae chicks in the West Antarctic Peninsula to aid in autonomously tracking their age. Understanding the phenological communication patterns of vocal-dependent seabirds can help measure the impact of climate change on this indicator species through non-invasive methods.

Applying soundscape: A matter of participation

Defined as the acoustic environment understood by people in context, the soundscape encapsulates the myriad sounds that shape our daily lives (ISO12913 series). In the intricate tapestry of our sensory experiences, the soundscape emerges as a profound element, weaving together the diverse threads of auditory stimuli and social implications that surround us. Soundscape is not merely an assortment of sounds; rather, it is a complex interplay of natural and human-made elements that contribute to the acoustical and social identity of a place. Participation in the planning and modification of an acoustic environment requires an active and creative approach, it calls for a targeted engagement with the proposed redesigns or reorganizations. Participating in the soundscape approach also entails promoting acoustic ecology and the responsible management of acoustic environments. This involves efforts to minimize noise pollution, protect natural soundscapes, and create spaces where diverse sounds can coexist harmoniously. The paper will discuss different aspects of participation that offers numerous benefits, and as a participatory experience it opens new avenues for creativity, well-being, and community building in our ever-evolving acoustic living situations.

Acoustic ecology of Adélie penguins in the West Antarctic Peninsula

Adélie penguins (Pygoscelis adeliae) are bioindicators for the rapidly changing Antarctic environment, making understanding their population dynamics and behavior of high research priority. However, collecting detailed population data throughout the breeding season on many colonies is difficult due to Antarctica’s harsh conditions and remote location. The colonial breeding ecology of Adélie penguins has led to the evolution of a highly vocal species with individualized calls, making them well-suited for passive acoustic monitoring (PAM) with autonomous recording. PAM units can potentially provide an easily deployable and scalable way to collect fine-scale data on population estimates and breeding phenology. Here I present a framework for using acoustic indices to monitor phenology of dense penguin colonies even under high wind conditions. I evaluate the relationship between acoustic indices such as RMS amplitude and penguin colony size between distinct breeding stages (incubation, guard, crèche, and fledge) on Torgersen and Humble Islands in the West Antarctic Peninsula with an automated pipeline implemented in R. Using PAM to interpret penguin vocalizations for population size and breeding phenology estimates could lead to the development of a real-time remote monitoring system over a large spatial footprint, revealing Adélie penguin responses to climate change.

The legacy of R. Murray Schafer - twenty-four hours of soundscape measurements : an analysis of the acoustic ecology of a city centre

Raymond Murray Schafer, a composer, writer, environmentalist, and long-time leading figure in acoustic ecology, would have celebrated his 91st birthday this year. A versatile artist and theorist, he expanded his musical compositions to include a layer of natural-environment sound and took interpretations of his concert-hall compositions outdoors. This text works with Schafer's approach to acoustic ecology. By drawing on acoustic-ecological research mapping and the relationships between people and their environment, it shows Schafer's approaches to the investigation of our sound environment and updates of some of his theories with the soundscape of the city centre of Brno, Czech Republic.

Presenting Archaeoacoustics Results Using Multimedia and VR Technologies

Abstract Music and sound cannot be experienced through writing and numbers. Writing freezes time onto paper; as a time-based medium, sound cannot be heard without temporal motion, and acoustic metrics are silent data. For a complete experience of sound, it needs to engage our bodies. Digital multimedia technologies offer powerful approaches to understanding the acoustics of the past, and this work will explore a number of those affordances. In particular, this work explores the use of apps that illustrate archaeoacoustic effects, set digitally within visual and acoustic archaeological cultures. The ways of immersing audiences through projection, acoustic simulation, field and studio recordings, and musical performance will be discussed. The use of virtual reality (VR) headsets is explored to create a sense of deep-flow and presence amongst audiences, total immersion in an experiential phenomenological understanding of interacting audio and visual fields, as well as setting such results within an appropriate context. This study will examine how acoustics results at caves in Northern Spain, in various phases of Stonehenge, and at Paphos Theatre (all World Heritage Sites) can be explored using VR and multimedia technologies, evaluating the comparative advantages of the use of different technologies. It proposes that such integration of visual and sonic modelling using interactive digital technologies is effective as a non-representational theory approach to compliment empirical studies, allowing understanding that goes beyond numerical analysis and binary dialectics to engage directly with the material of archaeological sites in an embodied manner, and address the real-world complexities of acoustic ecologies and their contexts.

Reconfiguring Ocean Life by Thinking with Oceans and Whales Witi Ihimaera’s The Whale Rider and Zakes Mda’s The Whale Caller

Whales are stranded along the Atlantic Ocean in North America, the press spread the news in February 2023. Witi Ihimaera’s novel The Whale Rider (1987) frames a similar episode: “Two hundred whales, lifeless on the beach and in the water” (1987, 85). Stranded whales are protagonists in Zakes Mda’s The Whale Caller (2005), too. Here, a whale is the pretext to explore gender issues, role models in traditional indigenous societies, capitalist economy and tourism, the perception of chieftainship, shamans and spirituality. Making use of acoustic ecology (Carson 1955; Shafer 1994), whales ‘speak’ of relations between humans, non-humans (Huggan 2021) and oceans (Regazzoni 2022).

Mapping tinnitus

ABSTRACT In this article, I offer a critical reflection on the production of “tinnitus maps” as part of the Arts and Humanities Research Council project, Tinnitus, Auditory Knowledge and the Arts. Influenced by both methods and critiques of sound mapping, tinnitus maps mark an attempt to creatively document the relationship between aurality, context and place. Tinnitus maps depart from sound mapping’s focus on the aural specificity of “proper noun” places, instead depicting tinnitus as a mode of aurality. This article situates these maps in relation to the practices and discourses of acoustic ecology: a field that has been associated with and been influential for various methods of sound mapping. I posit that tinnitus maps serve to amplify the exclusions created by acoustic ecology’s aesthetic moralism and investment in normate aurality, while also offering novel insights into tinnitus’ spatial and relational constitution.

Elephant in the Matrix

With the maturing of sound studies, and its intersection with critical studies, more attention is being given to the Anglo-Euro-centric and hegemonic legacy of acoustic ecology, as well as the cultural dimensions of sound studies. Discord between the practice of sound inquiry and sound ethnography has thus ensued, signaling the need to reexamine language and concept limitations, long-standing methods, approaches, and assumptions embedded in sonic research. In this paper we question the colonial foundations of sound studies in relation to researcher positionality and the conflicted task of attempting decoloniality from within the colonial institution that is academia. Beginning with a vignette, we position ourselves at the intersections of the discourse of coloniality and empire, and ask how sound studies, and indeed our own scholarship, mobilizes structures of power. Then we review major strands of decolonial scholarship within Canada and from key Latin American theorists, in relation to Canadian sound studies. And lastly, we offer what we call a speculative sonic framework for decolonial praxis: a set of suggestions for researchers that starts with the experiential more broadly, and the sonic more specifically, to mobilize decolonial praxis at the core of the research design.

Exploring art-making as research enquiry: Methods, materiality and intentionality

This article discusses the intersections of art-making and research enquiry, focusing on methods, materiality and intentionality. In response to the request to contribute to an archive of creative methodological processes, the author examines a methodology he is developing for co-creating artistic acoustic ecologies with the Great Lakes. It raises questions about the role of practice-based research in generating new forms of enquiry and systems of knowledge while examining the barriers to achieving legitimacy for artistic practices within the research landscape. The article explores ethical, technological and artistic considerations within the context of the author’s auto-ethnographic lens of an artist working in an era that demands verbalization as a primary articulation of knowledge and cultural expression. The author, a practising visual artist, musician and Ph.D. student in the research-creation-based Media and Design Innovation programme at Toronto Metropolitan University, discusses the need for concrete examples of how artistic research methods are effective.

Acoustic recording tags provide insight into the springtime acoustic behavior of sei whales in Massachusetts Bay.

The acoustic ecology of sei whales (Balaenoptera borealis) is poorly understood due to limited direct observation of the behavioral context of sound production and individual behavior. Suction cup-attached acoustic recording tags were deployed on sei whales to unambiguously assign call types and explore the acoustic behavior of this endangered species. Twelve tag deployments resulted in ∼173 h of acoustic data and 1030 calls. Sound types included downsweeps and three previously undescribed call types. Knocks were short duration (<1 s), with an average peak frequency of 330 Hz. Pulse type 1 and pulse type 2 calls, typically produced in sequences, were short in duration (0.08 and 0.28 s) and low in average peak frequency (50 and 26 Hz), with relatively high received levels. Average call rates for all call types combined were three calls per hour, but increased during twilight. Sex differences in call type usage included a higher use of pulses by females and knocks by males. Calls were almost exclusively produced at depths <10 m, although whales rarely dove deeper in this study. These data provide a more comprehensive picture of the acoustic and behavioral ecology of sei whales than previously possible, which can inform future conservation efforts for this endangered species.

Polyphony, sonic texture and acoustic ecology in Cynan Jones’s Stillicide

Polyphony, sonic texture and acoustic ecology in Cynan Jones’s <i>Stillicide</i>

An interdisciplinary journey towards an aesthetics of sonification experience

The aesthetic dimension has been proposed as a potential expansion of sonification design, creating listening pieces that reach the goal of effective data communication. However, current views of aesthetics still aim at optimising mapping criteria to convey the ‘right meaning’, maintaining a mostly functional view on what is considered a successful sonification. This paper proposes an interdisciplinary approach to the aesthetics of sonification experience, grounded on theoretical foundations from phenomenology of interaction, post-phenomenology, cross-cultural studies, acoustic ecology and deep listening. From this journey, we present the following design insights: (1) the design of sonifications becomes a design for experience, (2) co-designed during the interaction with each participant; (3) the sonification artefact gains a mediating role that guides the participant’s intentions in the sonification space; (4) the aesthetics of a sonification experience generates a multistable phenomenon, offering new opportunities to experience multiple perspectives over data; (5) the interaction between human participants and the sonic emanations compose a dialogic space. A call for action to reframe the sonification field into novel design spaces is now open, with aesthetics gaining a transformational role in sonification design and interaction.

Acoustic ecology of harbour porpoise (Phocoena phocoena) between two U.S. offshore wind energy areas

Abstract Offshore wind energy is set to develop rapidly in waters off the east coast of the United States. There is considerable overlap between areas proposed for offshore wind development and harbour porpoise habitats in the Gulf of Maine (GOM) and Southern New England waters. Baseline data on the occurrence and foraging activity of porpoises was collected using 10 echolocation-click detectors (F-PODs) from 2020 to 2022. Porpoises were present year-round in the GOM with peak detections in the summer and fall. In line with previous reported distribution patterns, porpoise occurrence in Southern New England was high in fall, winter and spring, but porpoises were largely absent in the summer. One site in the GOM, Mount Desert Rock (MDR), was an anomaly as porpoise detections here were highest in the winter. On average, foraging was identified in 29% of all porpoise detections, with the most foraging occurring at MDR (53%). Results from generalized additive models suggest that time of year, hour of day, lunar illumination, and temperature are significant contributors to porpoise presence and/or foraging effort. European studies show that harbour porpoises exhibit behavioural changes, disruption of foraging and displacement due to wind energy development. Therefore, early identification of areas of importance, mitigating impacts, and monitoring changes is essential for the protection of this species in US waters.

Assessing the soundscape of heritage streets in Melaka: the ISO/TS 12913-2:2018 method of data collection

The value of heritage sites is often distinguished through their architectural and physical features. However, the characteristic of a place is forged through the combination of multiple sensory elements. Acoustic is an essential element in the study of heritage spaces related to music, performance, congregations, etc. However, in the study of heritage sites, the acoustic elements are often overlooked even though they are an important element that adds spirit to the place. How people perceive their environment aurally is just as important as how they perceive it visually. This paper discusses the application of soundscape assessment methods recommended in ISO/TS 12913-2:2018. The technical specification presented comprehensive guidelines and alternatives on how a soundscape assessment should be conducted. The field study method and all its data collection protocols are reviewed and explored for implementation in the study of heritage streets in Melaka World Heritage Site. Characterising the soundscape profile of Melaka heritage streets will assist in understanding another facet of user experience and the acoustic ecology of the site.

The role of acoustics within the sensory landscape of coral larval settlement

Recruitment of coral larvae on reefs is crucial for individual survival and ecosystem integrity alike. Coral larvae can detect and respond to a wide range of biotic and abiotic cues, including acoustic cues, to locate suitable sites for settlement and metamorphosis. However, the acoustic ecology of coral larvae, including how they perceive auditory cues, remains poorly understood. In this mini-review we consider both ex situ physiology and behavior, and in situ ecological and behavioral studies, to first provide an updated overview of the abiotic and biotic cues used by coral larvae to guide settlement. We then explore in detail the use of acoustic cues and the current literature on behavioral responses to acoustic stimuli. Finally, we discuss gaps in our understanding of the mechanisms by which coral larvae detect acoustic cues, highlighting a novel application of technology to explore these sensory capabilities. We also address how larval phonotaxis, i.e., the ability to orient to a sound cue, can be applied to coral reef conservation. Current research suggests that acoustic cues are likely used at small spatial scales, and that coral larvae may have directional acoustic sensitivity enabling phonotactic behavior. Recruitment of coral larvae on reefs is significantly influenced by habitat-specific soundscape variation and likely affected by anthropogenic disturbance. We propose a novel application of the remote sensing technology, micro-scanning laser Doppler vibrometry (LDV), to quantify the micromechanical responses of putative acoustically sensitive epidermal microstructures. We then highlight the potential for incorporation of acoustic enrichment techniques in coral reef conservation and restoration interventions.

Scaling Refrains

Within and beyond the 1950s environmental framework, the global awareness toward the anthropogenic environmental impact and risk has stimulated critical discussions of the interrelations of human, nature, and material productive forces with an expansion of the planetary scale interrelations and place imaginaries as multiplicities. Parallel to the global transformation of risk societies, Turkiye has been dealing with environmental risks that transform its ecologies in acoustical and political senses. However, the historical and recently manifested discourses about sound and soundscapes have remained contingencies of the national singular narratives. By attending to the rhizomatic multiplicities in soundscapes along with the changing environmental definitions of sense of place, in this article, I examine refrains and investigate the fundamental question of why a particular acoustic ecology is recognized in singular forms and monophonies that are representative of this place imaginary independent of the forces in a material sense. Via the new terms that I coin, origin-essence and impetus, I further analyze refrains’ role in constructing communal imaginaries centered around inter- and intra-nationality to present the ongoing modern silences, narratives of Islamic and secular binary divisions, and the monophony of soundscapes of Turkiye. In doing so, I examine post-Covid-19 mosque recitations and broadcasts in Ankara in relation to the mosque calls’ role in preventing the July 15th, 2016 military coup d’etat attempt, the historical dichotomy of makam and scale in relation to European colonialism and Turkish cosmopolitanism, and the significance of refrains in Béla Bartók’s and Adnan Saygun’s ethnomusicological research in Central Anatolia.

At the Crossroads: Introducing New Work in Early America and Colonial Latin America

At the Crossroads: Introducing New Work in Early America and Colonial Latin America

The Echo of Voices after the Fall of the Aztec Empire

Abstract The recent quincentennial of the Mexica forces' defeat at the hands of a Spanish-led coalition invites us to reflect on the changes in the region's acoustic ecology, the layers of sound that reverberated across geographic spaces. Expressions of sound allow us to consider the actions of past actors in relation to their physical surroundings, the stimulation of the senses, and patterns of religious conversion that guided social behavior. Vocal sounds produced by people of various ethnic and racial backgrounds formed part of this aural environment, and they carried meaning that has often escaped the attention of scholars. An analysis of routines of indoctrination centered on vocal modulations reveals that authorities hierarchized different forms of sounds, from singing and praying—which they encouraged—to screams and muffled noises such as murmur and chatter—which they attempted to silence. These routines took shape during daily masses, theater presentations, civic and religious rituals, confession, and, in some cases, formal training.

ENSINAR EXIGE ESCUTAR: UMA REFLEXÃO SOBRE ENSINO-APRENDIZAGEM E ECOLOGIA ACÚSTICA NAS ESCOLAS DE ARARAS-SP

In this article we intend to look into the soundscapes of schools in the city of Araras-SP and reflect on how their sounds can influence the teaching-learning process. For that, we will use a scientific literature review and a field study based on the experience of the author teachers who work in the teaching staff of the Municipal Education Network. We will approach the concept of soundscape, based on the theory of Canadian composer and educator R. Murray Schafer, who seeks to analyze in his works the unbridled growth of noise pollution in our contemporary life. Ultimately, proposals are sought to build a school environment that thinks about acoustic ecology, to make this pedagogical space more pleasant, where people can learn from each other. intend to synthesize Schafer's thoughts and connect them with a proposal to improve communication in schools, an education