Animal Vocalizations Research Articles

The influence of spatial features and atmospheric conditions on African lion vocal behaviour

Long-distance vocalization is a characteristic of African lion, Panthera leo, behaviour and is important for maintaining territorial boundaries as well as locating distant group members. Vocal signalling is, however, a flexible behaviour that involves varying costs and benefits depending on environmental, social and spatial factors. Motivated by previous data collection limitations, we developed a novel approach to investigate the influence of atmospheric conditions and animal home range geography on lion vocal behaviour using acoustic and accelerometer biologgers. To compensate for the short lifetime of the acoustic biologger, we trained a machine-learning model to detect lion roars from long-term acceleration signals which yielded over 500 nights of data from seven individual lions. Analysis of detected roar events revealed that vocalizations occurred mainly at night with a peak just before dawn. The relative likelihood of vocalization was negatively related to wind speed and temperature and positively related to absolute humidity suggesting that lions preferred to roar under conditions that reduce sound attenuation and thereby maximize calling area. Roar occurrence was found to be dependent on an animal's location relative to its home range with lions demonstrating an apparent avoidance for vocalizing beyond the home range boundary. Lions were also more likely to roar repeatedly while closer to rivers and water points within their home range. This study is the first of its kind and not only improves the understanding of lion vocal behaviour but can also inform new approaches for recording animal vocalizations remotely.

Robustness to Noise in the Auditory System: A Distributed and Predictable Property.

Background noise strongly penalizes auditory perception of speech in humans or vocalizations in animals. Despite this, auditory neurons are still able to detect communications sounds against considerable levels of background noise. We collected neuronal recordings in cochlear nucleus (CN), inferior colliculus (IC), auditory thalamus, and primary and secondary auditory cortex in response to vocalizations presented either against a stationary or a chorus noise in anesthetized guinea pigs at three signal-to-noise ratios (SNRs; −10, 0, and 10 dB). We provide evidence that, at each level of the auditory system, five behaviors in noise exist within a continuum, from neurons with high-fidelity representations of the signal, mostly found in IC and thalamus, to neurons with high-fidelity representations of the noise, mostly found in CN for the stationary noise and in similar proportions in each structure for the chorus noise. The two cortical areas displayed fewer robust responses than the IC and thalamus. Furthermore, between 21% and 72% of the neurons (depending on the structure) switch categories from one background noise to another, even if the initial assignment of these neurons to a category was confirmed by a severe bootstrap procedure. Importantly, supervised learning pointed out that assigning a recording to one of the five categories can be predicted up to a maximum of 70% based on both the response to signal alone and noise alone.

Workflow and convolutional neural network for automated identification of animal sounds

The use of passive acoustic monitoring in wildlife ecology has increased dramatically in recent years as researchers take advantage of improvements in autonomous recording units and analytical methods. These technologies have allowed researchers to collect large quantities of acoustic data which must then be processed to extract meaningful information, e.g. target species detections. A persistent issue in acoustic monitoring is the challenge of efficiently automating the detection of species of interest, and deep learning has emerged as a powerful approach to accomplish this task. Here we report on the development and application of a deep convolutional neural network for the automated detection of 14 forest-adapted birds and mammals by classifying spectrogram images generated from short audio clips. The neural network performed well for most species, with precision exceeding 90% and recall exceeding 50% at high score thresholds, indicating high power to detect these species when they were present and vocally active, combined with a low proportion of false positives. We describe a multi-step workflow that integrates this neural network to efficiently process large volumes of audio data with a combination of automated detection and human review. This workflow reduces the necessary human effort by > 99% compared to full manual review of the data. As an optional component of this workflow, we developed a graphical interface for the neural network that can be run through RStudio using the Shiny package, creating a portable and user-friendly way for field biologists and managers to efficiently process audio data and detect these target species close to the point of collection and with minimal delays using consumer-grade computers.

Detecting and Tracking the Positions of Wild Ungulates Using Sound Recordings.

Monitoring wild ungulates such as deer is a highly challenging issue faced by wildlife managers. Wild ungulates are increasing in number worldwide, causing damage to ecosystems. For effective management, the precise estimation of their population size and habitat is essential. Conventional methods used to estimate the population density of wild ungulates, such as the light census survey, are time-consuming with low accuracy and difficult to implement in harsh environments like muddy wetlands. On the other hand, unmanned aerial vehicles are difficult to use in areas with dense tree cover. Although the passive acoustic monitoring of animal sounds is commonly used to evaluate their diversity, the potential for detecting animal positions from their sound has not been sufficiently investigated. This study introduces a new technique for detecting and tracking deer position in the wild using sound recordings. The technique relies on the time lag among three recorders to estimate the position. A sound recording system was also developed to overcome the time drift problem in the internal clock of recorders, by receiving time information from GPS satellites. Determining deer position enables the elimination of repetitive calls from the same deer, thus providing a promising tool to track deer movement. The validation results revealed that the proposed technique can provide reasonable accuracy for the experimental and natural environment. The identification of deer calls in Oze National Park over a period of two hours emphasizes the great potential of the proposed technique to detect repetitive deer calls, and track deer movement. Hence, the technique is the first step toward designing an automated system for estimating the population of deer or other vocal animals using sound recordings.

Female and male song exhibit both parallel and divergent patterns of cultural evolution: A long-term study of song structure and diversity in tropical wrens

Abstract Animal culture changes over time through processes that include drift, immigration, selection, and innovation. Cultural change has been particularly well-studied for animal vocalizations, especially for the vocalizations of male animals in the temperate zone. Here we examine the cultural change in the vocalizations of tropical Rufous-and-white Wrens (Thryophilus rufalbus), quantifying temporal variation in song structure, song type diversity, and population-level distribution of song types in both males and females. We use data from 10 microsatellite loci to quantify patterns of immigration and neutral genetic differentiation over time, to investigate whether cultural diversity changes with rates of immigration. Based on 11 yr of data, we show that the spectro-temporal features of several widely-used persistent song types maintain a relatively high level of consistency for both males and females, whereas the distribution and frequency of particular song types change over time for both sexes. Males and females exhibit comparable levels of cultural diversity (i.e. the diversity of song types across the population), although females exhibit greater rates of cultural change over time. We found that female changes in cultural diversity increased when immigration is high, whereas male cultural diversity did not change with immigration. Our study is the first long-term study to explore cultural evolution for both male and female birds and suggests that cultural patterns exhibit notable differences between the sexes.

Temporal attention based animal sound classification

Temporal attention based animal sound classification

Social bonding and credible signaling hypotheses largely disregard the gap between animal vocalizations and human music

Mehr et al. propose a theory of the evolution music that can potentially account for most animal vocalizations as precursors to human music. Therein lies its appeal but also its Achilles' heel, for the wider the range of animal vocalizations treated as premusical expressions, the wider the gap to human music. Here, I offer a few critical observations and constructive suggestions that I hope will help the authors strengthen their case.

Characterization and assessment of vocalization responses of cows to different physiological states

ABSTRACT The objective of our study was to characterize and assess the vocalization responses of cows in four different physiological states using different measurements and relate those to salivary cortisol concentrations as a possible indicator of stress. We characterized and assessed the vocalization responses of cows in four different physiological states: feed anticipation, estrus, communication between or among individuals, and parturition. We used video camera recordings of the calls made by the cattle during these four states. We measured the duration of the calls, intensity and pitch of vocalizations, and the formant, using vocalization analysis software. Two hundred and ninety calls were recorded from 32 cows during the study. Cortisol increased from the least values in communications and feed anticipation, to two-fold concentrations in estrus, and three-fold concentrations in parturition. All the formants tended to increase in the same order with the stress concentrations, whereas low intensity and lower pitched vocalizations were associated with greater cortisol concentrations during parturition. These results indicate that acoustic parameters of calls in each of the physiological states may reflect the stress level in cattle, and thus, the vocalization of animals could be an important behavioural indicator of their stress level.

Biophony in a noisy tropical urban forest fragment

Anthropogenic noise, which is part of an urban soundscape, can negatively affect the behaviour of wild animals. Here we investigated how biophony (animal sounds) was affected by noise in an urban Brazilian forest fragment. Our hypothesis was that noise and biophony would differ between the border and the centre of the forest fragment (i.e., lower biophony predicted in noisy areas). Two passive acoustic monitoring devices were used to record soundscapes one week per month, 24 hour per day, from May to July 2012. The Acoustic Complexity Index (ACI) was used to quantify biophony and the Power Spectral Density (PSD) to quantify urban noise. PSD and ACI were higher on the border than in the centre of the fragment. PSD was lower in July, while the ACI did not significantly vary between months. Noise levels were also higher on the border. Conversely, potential species richness was higher in the centre of the forest fragment. Higher biophony at noisy sites can be interpreted as behavioural responses of species for communicating in noisy areas. Alternatively, they could be the result of species segregation by degree of vocal plasticity or due to differences in composition of communities.

Franz Kafkas akustische Welten by Rüdiger Görner

Reviews 169 as follows: ‘Die Tochter sei also weder traurig noch böse über die verletzenden Worte der Mutter gewesen, sondern habe den Anschein erweckt, sie fühle sich geborgen’ [The daughter is neither sad nor angry about the mother’s hurtful words, rather she gives the impression that she feels secure, p. 155] and classifies this as an example of ‘satire’; the fact that Hannelore slept for thirty hours is supposed to be ‘grotesque’. While it would be worth discussing the terms ‘satire’ and ‘grotesque’ in detail and elaborating on the function of ‘irony’ in Schwab’s texts (the play with literality and irony is crucial to his works, as Grete’s statement quoted above suggests), this example points to a central problem of the monograph: its use of passages taken out of context to illustrate its thesis misses crucial points. For example, since Hannelore is traumatized and afraid, putting her thumb in her mouth indicates a regressive turn. Thus, this short episode can also be read as a supreme example of Schwab’s exposition of language as a vehicle for brutality. Moreover, Grete — like almost all of Schwab’s characters — is not reliable and, to some extent, ‘is spoken’ by language and thus by the discourses that constitute it. While Uertz-Jacquemain has invested much work in the content summary, the other chapters are often overshadowed by the existing comprehensive theoretical elaborations and analyses found in other Schwab scholarship. It would have been beneficial to reduce the content summary and the overall number of topics treated in favour of detailed elaboration on theoretical backgrounds, a focus on the proposed topic and a contextualization of the examples discussed to highlight the productive ambiguity of Schwab’s texts. Marina Rauchenbacher University of Vienna Franz Kafkas akustische Welten. By Rüdiger Görner. Berlin, Boston: De Gruyter, 2019. 183 pp. €92.95. ISBN 978–3-11054–224–0. The significance of Franz Kafka’s relationship to the acoustic was first noted by one of his contemporaries, Walter Benjamin. In his essay on Kafka in 1934, Benjamin comments on a photograph of the child Kafka in which ‘the auricle of a large ear’ listens in to the landscape around him (Selected Writings, II.ii, 800). Writing to Gershom Scholem in 1938, he noted that, ‘Kafka listened to tradition, and he who listens hard does not see. The main reason why this listening demands such effort is that only the most indistinct sounds reach the listener’ (Illuminations, p. 143). Benjamin’s remarks draw attention to two aspects of Kafka’s acoustic world: firstly, that Kafka’s own listening experiences and habits had an important impact on his writing; and secondly, that the hearing organ in Kafka is not always embodied. Indeed, it is at moments of detachment or mechanization of hearing that Kafka’s insights are most interesting. Rüdiger Görner’s study Franz Kafkas akustische Welten contributes to the aural turn in literary studies over the last three decades. Many of Kafka’s Reviews 170 writings, such as the stories ‘Der Bau’ or ‘Josefine, die Sängerin oder Das Volk der Mäuse’, with their unlocalizable and animal sounds, have already attracted comment from scholars of sound studies, but Görner here attempts a systematic investigation of acoustic moments throughout Kafka’s autobiographical, epistolary and literary writings. Görner’s guiding question is simply, ‘Wie hörte dieser Autor?’ [How did this author hear? p. 5]. To reverse the question, one might ask: how does writing reconstruct an auditory world? The book’s first section, ‘Befunde’ [Findings], begins with an examination of the auditory landscape that surrounded Kafka in the early twentieth century. Sociologists and public health officials were increasingly concerned about the crescendo of urban noise resulting in nervous breakdown. Theodor Lessing, whose treatise Der Lärm: Eine Kampfschrift gegen die Geräusche unseres Lebens [Noise: A Polemic against the Sounds of Our Lives] was published in 1908, founded the German anti-noise league in the same year. The Berlin microbiologist Robert Koch compared urban noise to an infection, a metaphor which was adopted by literary writers. Kafka was part of this consensus, complaining on several occasions of an inability...

The “sound of silence” in Granada during the COVID-19 lockdown

Abstract Exceptional circumstances in the city of Granada due to the COVID-19 lockdown have provided the opportunity to characterise the impact of humans on its urban acoustic climate. Traditional environmental noise management and urban sound planning usually take into account noise sources in the city, such as industrial activities or road traffic noise, in model estimations, as well as in empirical research. But trying to isolate human impact by itself, human activity including social activity, walking, talking or just going around the city, has always been a difficult or even impossible task. The COVID-19 lockdown measures have provided the opportunity to study urban climate as never before, affected just by natural or animal noise sources. Previous soundscape research at some iconic sites in the city of Granada carried out in 2019 before the lockdown and a special measuring campaign carried out at the same locations during the lockdown in 2020 offered valuable information on sound levels and local characteristics in order to carry out this comparison. Results show a great change in environmental noise levels that is interesting not only because of its magnitude, but also for its implications, especially at those sites where social human activity was an identifying characteristic. Natural or animal sounds became surprisingly evident at some study sites, especially where road traffic noise dramatically decreased, leading to significantly lower background noise levels. Important spectral changes are observed before and during the lockdown, suggesting a shift from anthropic to animal sources in the acoustic environment.

Co łączy i dzieli nazwy odgłosów zwierząt i ludzi?

The article provides is a comparison of the names of human and animal sounds, which belong to a larger collection of vocabulary that defines the world of auditory perceptions. The historical, grammatic and semantic regularities are identical to them. Differences are noticed in detailed meanings and in the pragmatic of these names, which includes among other things, a much higher incidence of the names of human sounds. Linguistic relativism is more closely covered by the names of animal sounds. The widespread use of animal names for sounds in relation to humans is accompanied by regular negative value and the expression of contempt against the person designated as sound performer.

Unsupervised acoustic classification of individual gibbon females and the implications for passive acoustic monitoring

Abstract Passive acoustic monitoring (PAM) has the potential to greatly improve our ability to monitor cryptic yet vocal animals. Advances in automated signal detection have increased the scope of PAM, but distinguishing between individuals—which is necessary for density estimation—remains a major challenge. When individual identity is known, supervised classification techniques can be used to distinguish between individuals. Supervised methods require labelled training data, whereas unsupervised techniques do not. If the acoustic signals of individuals are sufficiently different, the number of clusters might represent the number of individuals sampled. The majority of applications of unsupervised techniques in animal vocalizations have focused on quantifying species‐specific call repertoires. However, with increased interest in PAM applications, unsupervised methods that can distinguish between individuals are needed. Here we use an existing dataset of Bornean gibbon female calls with known identity from five sites on Malaysian Borneo to test the ability of three different unsupervised clustering algorithms (affinity propagation, K‐medoids and Gaussian mixture model‐based clustering) to distinguish between individuals. Calls from different gibbon females are readily distinguishable using supervised techniques. For internal validation of unsupervised cluster solutions, we calculated silhouette coefficients. For external validation, we compared clustering results with female identity labels using a standard metric: normalized mutual information. We also calculated classification accuracy by assigning unsupervised cluster solutions to females based on which cluster had the highest number of calls from a particular female. We found that affinity propagation clustering consistently outperformed the other algorithms for all metrics used. In particular, classification accuracy of affinity propagation clustering was more consistent as the number of females increased, and when we randomly sampled females across sites. We conclude that unsupervised techniques may be useful for providing additional information regarding individual identity for PAM applications. We stress that although we use gibbons as a case study, these methods will be applicable for any individually distinct vocal animal.

Animal Sound Classification Using Dissimilarity Spaces

The classifier system proposed in this work combines the dissimilarity spaces produced by a set of Siamese neural networks (SNNs) designed using four different backbones with different clustering techniques for training SVMs for automated animal audio classification. The system is evaluated on two animal audio datasets: one for cat and another for bird vocalizations. The proposed approach uses clustering methods to determine a set of centroids (in both a supervised and unsupervised fashion) from the spectrograms in the dataset. Such centroids are exploited to generate the dissimilarity space through the Siamese networks. In addition to feeding the SNNs with spectrograms, experiments process the spectrograms using the heterogeneous auto-similarities of characteristics. Once the similarity spaces are computed, each pattern is “projected” into the space to obtain a vector space representation; this descriptor is then coupled to a support vector machine (SVM) to classify a spectrogram by its dissimilarity vector. Results demonstrate that the proposed approach performs competitively (without ad-hoc optimization of the clustering methods) on both animal vocalization datasets. To further demonstrate the power of the proposed system, the best standalone approach is also evaluated on the challenging Dataset for Environmental Sound Classification (ESC50) dataset.

A spatial capture–recapture model to estimate call rate and population density from passive acoustic surveys

Abstract Spatial capture–recapture (SCR) models are commonly used to estimate animal population density from detections and subsequent redetections of individuals across space. In particular, acoustic SCR models deal with detections of animal vocalisations across an array of acoustic detectors. Previously published acoustic SCR methods either estimate call density (calls per unit space per unit time) rather than animal density itself, require an independently estimated call rate to estimate animal density, or discard data from all but one detected call from each individual. In this manuscript, we develop a new spatial capture–recapture model that estimates both call rate and animal density from the acoustic survey alone, without requiring an independently estimated call rate. Our approach therefore alleviates the need for the additional fieldwork of physically locating and monitoring individual animals. We illustrate our method and compare it to an existing approach using a simulation study and an application to data collected on an acoustic survey of the visually cryptic Cape peninsula moss frog Arthroleptella lightfooti. In the context of our acoustic survey, our calling animal density estimator has low bias, good precision and confidence intervals with appropriate coverage, yielding results that are consistent with previous studies of the same species. Our method can obtain accurate and precise estimates of animal density while eliminating the fieldwork burden associated with separately estimating call rate. We discuss how the development of our model's likelihood reveals a clear path to further extensions, which may incorporate features such as animal movement processes and uncertain individual identification.

Characterizing the early vocabulary profiles of preverbal and minimally verbal children with autism spectrum disorder.

Although preverbal and minimally verbal children with autism spectrum disorder represent a significant portion of the autism spectrum disorder population, we have a limited understanding of and characterization of them. Although it is a given that their lexical profiles contain fewer words, it is important to determine whether (a) the words preverbal and minimally verbal children with autism spectrum disorder produce are similar to the first words typically developing children produce or (b) there are unique features of the limited words that preverbal and minimally verbal children with autism spectrum disorder produce. The current study compared the early word profiles of preverbal and minimally verbal children with autism spectrum disorder to vocabulary-matched typically developing toddlers. Children with autism spectrum disorder produced proportionally more verbs than typically developing toddlers. Also, children with autism spectrum disorder produced proportionally more action and food words, while typically developing toddlers produced proportionally more animal words, animal sounds and sound effects, and people words. Children with autism spectrum disorder also produced "mommy" and "daddy" at lower rates. Our findings identified several areas of overlap in early word learning; however, our findings also point to differences that may be connected to core weaknesses in social communication (i.e. people words). The findings highlight words and categories that could serve as useful targets for communication intervention with preverbal and minimally verbal children with autism spectrum disorder.

Penentuan Awal Waktu Salat Wajib di Kota Sengkang dengan Menggunakan Metode Klasik dan Kontemporer

AbstractThe main problem in this research is how to determine the beginning of prayer times using classical methods and contemporary methods in Sengkang City. The subject matter is further divided into 1) How to determine the initial prayer time in Sengkang City using the classical method? 2) How to determine the beginning of prayer times in Sengkang City using contemporary methods? The purpose of this study is to obtain information related to how the people of Sengkang city determine the start of prayer time both classically and contemporary. The purpose of this research is to obtain information related to how the people of Sengkang city determine the start of prayer time both classically and contemporary. Researchers make observations, interviews and documentation in order to collect accurate and relevant data for research.This type of research is a qualitative field research in which the researcher collects data directly by going directly to the field to obtain more efficient data, while the data mining technique uses reference books related to research titles, journals, previous theses and observation methods of interviews and documentation. .The results obtained in this study are the first people in the city of Sengkang in determining the time of obligatory prayers using classical methods such as natural phenomena, shadows of objects, animal sounds and using methods compiled by angregurutta H. Muhammad Yunus Martan. Second, the majority of people in the city of Sengkang use the decree of the Ministry of Religion of Wajo Regency, thus indirectly the community uses the contemporary method used by the Ministry of Religion of the District. Wajo, namely using the formula for determining prayer times and using applications for determining prayer times, one of which is a pro Muslim.Implications The research in this thesis is a matter of determining the initial time of the obligatory prayers which the public must understand well. As for the suggestions and hopes from the author, namely, to everyone who covers the issue of worship, especially from the Ministry of Religion and astronomy students to carry out socialization and counseling related to determining the initial time of compulsory prayer.Kata Kunci: Salat, Klasik, Kontemporer

DHAMMONG : A RAIN RITUAL IN MADURA (A STUDY ON ITS HISTORY, FUNCTION, AND HISTOR ORY SIMBOLIC MEANING)

This article attempted to trace the existence of Dhâmmong tradition in the following scopes, namely: (1) Madurese perception against Dhâmmong , (2) the function and symbolic meaning of Dhâmmong in human life, and (3) the efforts of the Madurese community to preserve the Dhâmmong tradition. Through a descriptive phenomenological analysis, this study revealed that Dhâmmong is a hereditary tradition carried out by the Madurese community, it is urged by the community’s anxiety caused by the long dry season (némor lanjheng). Dhâmmong functionsas a means for salametan, paying respect for the ancestors, strengthening human relations (silaturrahim ), Bhek Rembhek, and nguri berkah (the fertility of the earth). The offerings and mouth-music by imitating the sounds of animals represent a strong desire and wishof the community for the immediate rainfall that could pour out blessings for the community. Hence, the community’s efforts to preserve Dhâmmong are: (1) introducing and involving the younger generation in the ritual, and (2) setting and changing the time sequence of Dhâmmong implementation from night to daytime.

Onomatopoeia in Omani Arabic

Onomatopoeia is believed to be of a widespread occurrence in all languages of the world though with different extents. Arabic language is attested to be rich in the use of onomatopoeia in speech, prose, and poetry. Omani Arabic, a unique variety of vernacular Arabic spoken in the Sultanate of Oman in the eastsouthern part of Arabia, likewise has numerous usages of onomatopoeic words in everyday life interactions. Both lexical and non-lexical onomatopoeia exist in Omani Arabic falling into three main categories: human sounds, animal sounds, and sounds associated with nature and objects. Onomatopoeic sounds appear in different syllabic forms including full syllables and non-syllabic forms with one or more consonants. The use of voiceless sounds and fricatives is more prevalent compared to other types of sounds. Cases are attested of sounds captured in diverse manners exhibiting alternation among sounds close in place of articulation as well as between emphatic sounds and their non-emphatic counterparts. The use of fricatives is used to mark the duration of sounds as opposed to the use of plosives employed to show abruptness and short duration of sounds. Morphologically, most of these words are used as verbs and derivative nouns. Reduplication is likewise used to mark the intensity and duration of actions signified by these sounds.

Utility of acoustic indices for ecological monitoring in complex sonic environments

With the continued adoption of passive acoustic monitoring as a tool for rapid and high-resolution ecosystem monitoring, ecologists are increasingly making use of a suite of acoustic indices to summarise the sonic environment. Though these indices are often reported to well represent some aspect of the biology of an ecosystem, the degree to which they are confounded by various extraneous sonic conditions is largely unknown. We conducted an aural inventory across 23 field sites in Okinawa to identify the number of unique animal sounds present in recordings. Using these values of ‘measured richness’, we then examined how the performance of 11 commonly-used acoustic indices varied across a range of sonic conditions (including in the presence and absence of insect stridulations, audible wind or rain, and human-related sounds). Our analysis identified both well- and poor-performing acoustic indices, as well as those that were particularly sensitive to sonic conditions. Only two indices reflected measured richness across the full range of sonic conditions examined. A few indices were relatively insensitive to extraneous sonic conditions, but no index correlated with measured richness when masked by sound from broadband stridulating insects. Our results demonstrate considerable sensitivity of most commonly used acoustic indices to confounding sonic conditions, highlighting the challenges of working with large acoustic datasets collected in the field. We make practical recommendations for acoustic index use based on study design, with the aim of identifying the suite of acoustic indices with greatest utility as indicators for rapid biodiversity monitoring and management of the world’s natural soundscapes.