Acoustic Censusing and Individual Identification of Birds in the Wild

Avian vocal individuality carries information that can be utilized as an alternative to physical tagging of individuals. However, it is rarely used in conservation tasks despite rapidly-expanding use of passive acoustic monitoring techniques. Reliable acoustic individual recognizers and accurate quantifiers of population size remain elusive, which discourages the use of vocal individuality for monitoring, wildlife management, and ecological research. We propose a neuro-fuzzy framework that allows discrimination of individuals by their calls, the discovery of unexpected individuals in a set of recordings, and estimation of population size using solely sound. Our method, tested using data collected in the wild, allows rapid individual identification and even acoustic censusing without prior information from the recorded individuals. We achieve this by integrating a fuzzy classification and clustering methodology (LAMDA) into a Convolutional Deep Clustering Neural Network (CDCN). Our approach will benefit monitoring for conservation, and paves the way towards robust individual acoustic identification in species whose handling is time-consuming, culturally or ethically problematic, or logistically difficult.

Acoustic Identification of Sentence Accent in Speakers with Dysarthria: Cross-Population Validation and Severity Related Patterns

Dysprosody is a hallmark of dysarthria, which can affect the intelligibility and naturalness of speech. This includes sentence accent, which helps to draw listeners’ attention to important information in the message. Although some studies have investigated this feature, we currently lack properly validated automated procedures that can distinguish between subtle performance differences observed across speakers with dysarthria. This study aims for cross-population validation of a set of acoustic features that have previously been shown to correlate with sentence accent. In addition, the impact of dysarthria severity levels on sentence accent production is investigated. Two groups of adults were analysed (Dutch and English speakers). Fifty-eight participants with dysarthria and 30 healthy control participants (HCP) produced sentences with varying accent positions. All speech samples were evaluated perceptually and analysed acoustically with an algorithm that extracts ten meaningful prosodic features and allows a classification between accented and unaccented syllables based on a linear combination of these parameters. The data were statistically analysed using discriminant analysis. Within the Dutch and English dysarthric population, the algorithm correctly identified 82.8 and 91.9% of the accented target syllables, respectively, indicating that the capacity to discriminate between accented and unaccented syllables in a sentence is consistent with perceptual impressions. Moreover, different strategies for accent production across dysarthria severity levels could be demonstrated, which is an important step toward a better understanding of the nature of the deficit and the automatic classification of dysarthria severity using prosodic features.

Platylomia kohimaensis n. sp.—a new cicada species (Hemiptera: Cicadidae) from the Naga Hills in the Eastern Himalayas

A new cicada species, Platylomia kohimaensis n. sp., belonging to the Platylomia radha group is described from the Naga Hills in the eastern Himalayas. It is a dusk singing, large-sized cicada that calls for a short window during the evening twilight hours. Timbalisation is in the form of a continuous and regular cackling. Photographs of adult male and female along with genitalia illustration and distribution map are provided. A sonogram along with Acoustic Identification Card is also provided.

Method for Calculating the Sound Pressure in Conductors when Identifying Them by the Acoustic Method

A promising method of identifying conductors in the conditions of agricultural enterprises is the use of acoustic identification tools that allow it to be carried out without disconnecting electrical receivers from the network, without violating the insulation of the identified conductors. The design of devices for acoustic identification requires the development of a methodology for calculating the sound pressure level in conductors when an acoustic signal is applied to them, depending on such factors as the distance from the identification point to the signal source, the cross section and material of the conductor cores, its insulation material, and the frequency of the signal being supplied. (Research purpose) The research purpose is in developing a methodology for calculating the parameters of the propagation of acoustic signals in conductors when identifying them using acoustic signals. (Materials and methods) The article presents the analysis of existing methods for calculating the acoustic characteristics of solids. The article describes the developed methodology for calculating the parameters of acoustic signal propagation in conductors when identifying them using acoustic signals and tested it using practical tests. (Results and discussion) The main parameter of acoustic signals in conductors when they are identified by acoustic means is the sound pressure level. Authors have developed a method for calculating the sound pressure level in conductors, taking into account such factors as the length of the identified conductor, the frequency of the acoustic signal, the conductor cross-section, the speed of sound waves in conductive cores and insulating materials. The article presents practical experiments to test the applicability of the developed methodology. (Conclusions). To date, acoustic signals are not used to identify conductors, a method for calculating the sound pressure level in conductors has not been developed, taking into account various factors. Authors developed a methodology and performed theoretical calculations of the sound pressure level in the conductors. Based on the results of practical experiments with the use of a control and measuring device, the applicability of the proposed methodology was confirmed.

Taxonomic revision of grass frogs (Ptychadenidae, Ptychadena) endemic to the Ethiopian highlands

Frogs of the genus Ptychadena that inhabit the Ethiopian highlands serve as a model system to understand biogeography, diversification, and adaptations to high elevations. Despite recent studies focusing on the systematics of this group, the taxonomy of the Ptychadena neumanni species complex remains only partially resolved, owing largely to the morphological resemblance of its members. Here, the taxonomy of this historically problematic group of frogs is revised by integrating morphological and molecular analyses on both century-old type specimens and more recently collected material. Based on these multiple lines of evidence, the P. neumanni species complex is shown to be more speciose than previously thought and four new species are described. With the aim of clarifying and stabilizing the taxonomy of the group, six species are also re-described and morphological and acoustic identification keys are provided. This study also establishes species distribution maps and reveals important differences in range size between the members of the P. neumanni complex, calling for adapted conservation measures across the Ethiopian highlands.