Zygosity Effects on Human Voice: Fundamental Frequency Analysis of Brazilian Twins' Speech.

Voice production can be influenced by interindividual variations related to genetic, physiological, behavioral, and several environmental factors. Here we examined the effect of zygosity on speaking fundamental frequency (F0) statistical descriptors. Our aims were: (1) to determine whether the genetic similarity between monozygotic (MZ) and dizygotic (DZ) twins affects F0 characteristics, and (2) to quantify the contribution of genetic factors to these characteristics. The study involved 79 same-sex twin pairs of Brazilian Portuguese speakers, comprising 65 MZ and 14 DZ twins, aged 18 to 66 years (31.7 ± 11.6 years), with 21 male and 58 female pairs. Participants were recorded while uttering a greeting phrase and the Brazilian Portuguese version of the 'Happy Birthday to You' song. Speech segments were analyzed using Praat free software, and F0 measures were automatically extracted in both Hertz and semitone scales. Statistical descriptors, including centrality, dispersion, and extreme values of F0 were examined, and the ACE model (i.e., total genetic effects, A; shared environmental influences, C; and nonshared environmental influences, E) was employed to estimate the additive effect;ts of monozygosity. As anticipated, we observed a zygosity effect on several F0 parameters, with more similarity between MZ twins compared to DZ twins. We discuss the genetic influences on F0 parameters and the absence of a monozygosity effect in two of them. Additionally, we briefly address potential biases associated with the selected measurement scale for statistical modeling. Finally, we explore the influence of genetic factors on F0 patterns, as well as environmental, life history and linguistic factors, particularly concerning F0 variation in speech.

Convolutional Neural Networks for Real Time Classification of Beehive Acoustic Patterns on Constrained Devices.

Recent research has demonstrated the effectiveness of convolutional neural networks (CNN) in assessing the health status of bee colonies by classifying acoustic patterns. However, developing a monitoring system using CNNs compared to conventional machine learning models can result in higher computation costs, greater energy demand, and longer inference times. This study examines the potential of CNN architectures in developing a monitoring system based on constrained hardware. The experimentation involved testing ten CNN architectures from the PyTorch and Torchvision libraries on single-board computers: an Nvidia Jetson Nano (NJN), a Raspberry Pi 5 (RPi5), and an Orange Pi 5 (OPi5). The CNN architectures were trained using four datasets containing spectrograms of acoustic samples of different durations (30, 10, 5, or 1 s) to analyze their impact on performance. The hyperparameter search was conducted using the Optuna framework, and the CNN models were validated using k-fold cross-validation. The inference time and power consumption were measured to compare the performance of the CNN models and the SBCs. The aim is to provide a basis for developing a monitoring system for precision applications in apiculture based on constrained devices and CNNs.

The resonant behavior of airborne standing-wave acoustic levitators based on arrays of ultrasonic transducers.

Recently airborne standing-wave acoustic levitation has seen great advances, and its applicability has been broadened due to the development of cavities constructed with arrays of compact ultrasonic sources. Yet, the numerical methods employed to study and predict the pressure distributions inside these cavities do not consider the effect of multiple reflections on the boundaries, hiding their resonant effects. This work presents an analytical, numerical, and experimental study of the effect of multiple reflections inside ultrasonic cavities based on arrays of transducers exhibiting their influence on the pressure amplitudes of focused standing waves. Our numerical results come from a modified version of the Matrix Method to numerically compute the multiple wave reflections of cavities constructed by two opposite arrays of multiple compact sources as boundaries. The correlation between numerical and experimental results reveals that intra-cavity reflections are relevant in focused axisymmetric cavities based on two arrays of multiple ultrasonic sources having a considerable impact on the amplitude of the standing waves and consequently, on the acoustic levitation performance. Thus, intra-cavity reflections must be considered for optimal cavity designs.

Cepstral Acoustic Measurements: Influence of Speech Task and Degree of Vocal Deviation.

OBJECTIVE: To analyze whether there are differences in the cepstral measures obtained in different speech tasks, depending on the presence and degree of vocal deviation, and to analyze if there is a correlation between the cepstral measures obtained from different speech tasks and the general degree of vocal deviation. METHOD: Analysis of 258 vocal samples of the sustained vowel [a] and connected speech (counting numbers) from a database, including 160 dysphonic and 98 nondysphonic voices. The counting number samples were edited in three different durations: counting from 1 to 10, from 1 to 11, and from 1 to 20. Five speech-language pathologists (SLPs), voice specialists, carried out the perceptual-auditory judgment of the overall degree of vocal deviation (ODD) using the G from the overall dysphonia grade, roughness, breathiness, asthenia, and strain (GRBAS) scale. We extracted the cepstral peak prominence (CPP) and smoothed cepstral peak prominence (CPPS) measurements from all the vocal samples using an extraction script in the free software Praat. RESULTS: CPP and CPPS were different between dysphonic and nondysphonic individuals, regardless of the speech task, with lower values for dysphonic. Also, CPP values between the vowel and the connected speech tasks were different between both groups. Only the CPPS showed differences between all the speech tasks depending on the degree of vocal deviation. There was a strong negative correlation between the CPPSVowel, CPPS10, CPPS11, CPPS20, and the ODD, and a moderate negative correlation between CPPVowel, CPP10, CPP11, CPP20, and ODD. CONCLUSIONS: There are differences in the cepstral measures obtained in different speech tasks, depending on the presence of dysphonia and ODD. CPP and CPPS values are different between dysphonic and nondysphonic individuals in all speech tasks. There is a moderate negative correlation between CCP in the different speech tasks and ODD, while there is a strong negative correlation between CPPS in the different speech tasks and ODD.

Hearing preservation and quality of life in small to medium sized vestibular schwannomas after a wait and scan approach or stereotactic radiosurgery: a systematic review and meta-analysis.

BACKGROUND: The management of vestibular schwannomas (VS) encompasses a choice between conservative "wait-and-scan" (WAS) approach, stereotactic radiosurgery (SRS) or open microsurgical resection. Currently, there is no consensus on the optimal management approach for small to medium sized VS. This study aims to compared outcomes related to hearing in patients with small and medium sized VS who underwent initial treatment with WAS versus SRS. METHODS: A systematic review of the available literature was conducted using PubMed/MEDLINE, Embase, and Cochrane up December 08, 2023. Meta-analysis was performed using a random-effect model to calculate mean difference (MD) and relative risk (RR). A leave-one-out analysis was conducted. The risk of bias was assessed via the Risk of Bias in Non-randomized Studies-Interventions (ROBINS-I) and Cochrane Risk of Bias assessment tool (RoB-2). Ultimately, the certainty of evidence was evaluated using the GRADE assessment. The primary outcomes were serviceable hearing, and pure-tone average (PTA). The secondary outcome was the Penn Acoustic Neuroma Quality of Life Scale (PANQOL) total score. RESULTS: Nine studies were eligible for inclusion, comprising a total of 1,275 patients. Among these, 674 (52.86%) underwent WAS, while 601 patients (47.14%) received SRS. Follow-up duration ranged from two to eight years. The meta-analysis indicated that WAS had a better outcome for serviceable hearing (0.47; 95% CI: 0.32 - 0.68; p < 0.001), as well as for postoperative functional measures including PTA score (MD 13.48; 95% CI 3.83 - 23.13; p < 0.01), and PANQOL total score (MD 3.83; 95% CI 0.42 - 7.25; p = 0.03). The overall certainty of evidence ranged from "very low" to "moderate". CONCLUSIONS: Treating small to medium sized VS with WAS increases the likelihood of preserving serviceable hearing and optimized PANQOL overall postoperative score compared to SRS. Nevertheless, the limited availability of literature and the methodological weakness observed in existing studies outline the need for higher-quality studies.

Multilayer Structure Damage Detection Using Optical Fiber Acoustic Sensing and Machine Learning.

Over the past decade, distributed acoustic sensing has been utilized for structural health monitoring in various applications, owing to its continuous measurement capability in both time and space and its ability to deliver extensive data on the conditions of large structures using just a single optical cable. This work aims to evaluate the performance of distributed acoustic sensing for monitoring a multilayer structure on a laboratory scale. The proposed structure comprises four layers: a medium-density fiberboard and three rigid polyurethane foam slabs. Three different damages were emulated in the structure: two in the first layer of rigid polyurethane foam and another in the medium-density fiberboard layer. The results include the detection of the mechanical wave, comparing the response with point sensors used for reference, and evaluating how the measured signal behaves in time and frequency in the face of different damages in the multilayer structure. The tests demonstrate that evaluating signals in both time and frequency domains presents different characteristics for each condition analyzed. The supervised support vector machine classifier was used to automate the classification of these damages, achieving an accuracy of 93%. The combination of distributed acoustic sensing with this learning algorithm creates the condition for developing a smart tool for monitoring multilayer structures.

Living Together, Singing Together: Revealing Similar Patterns of Vocal Activity in Two Tropical Songbirds Applying BirdNET.

In recent years, several automated and noninvasive methods for wildlife monitoring, such as passive acoustic monitoring (PAM), have emerged. PAM consists of the use of acoustic sensors followed by sound interpretation to obtain ecological information about certain species. One challenge associated with PAM is the generation of a significant amount of data, which often requires the use of machine learning tools for automated recognition. Here, we couple PAM with BirdNET, a free-to-use sound algorithm to assess, for the first time, the precision of BirdNET in predicting three tropical songbirds and to describe their patterns of vocal activity over a year in the Brazilian Pantanal. The precision of the BirdNET method was high for all three species (ranging from 72 to 84%). We were able to describe the vocal activity patterns of two of the species, the Buff-breasted Wren (Cantorchilus leucotis) and Thrush-like Wren (Campylorhynchus turdinus). Both species presented very similar vocal activity patterns during the day, with a maximum around sunrise, and throughout the year, with peak vocal activity occurring between April and June, when food availability for insectivorous species may be high. Further research should improve our knowledge regarding the ability of coupling PAM with BirdNET for monitoring a wider range of tropical species.

Detailed Comparison of Acoustic Signals from Rehabilitated and Wild Franciscanas (Pontoporia blainvillei) Dolphins.

The franciscana dolphin is a small, vulnerable species often caught in artisanal gillnets. This study aims to provide a comprehensive assessment of their acoustic capabilities by using advanced equipment to collect a large dataset of wideband, continuous recordings. We examined the detailed acoustic signals of franciscana dolphins, comparing the sounds from rehabilitated dolphins in captivity with those of wild dolphins near fishing nets. Significant differences in acoustic characteristics were found between neonates and older dolphins, with juvenile and wild dolphins showing similar features. For the first time, repetition patterns in click production were identified, highlighting the importance of understanding the context of these sounds in regards to feeding and communication. This study emphasizes the need for detecting neonates for species protection and suggests the potential for developing acoustic classifiers specific to different age groups. Our findings offer valuable insights for conservation efforts and the development of protection strategies for franciscana dolphins.

Changes in call properties of Boana pulchella (Anura, Hylidae) in response to different noise conditions.

The increasing expansion of urban areas leads to the emergence of new noisy environments that can affect animal communication. Calls play a crucial role in the mating displays of anurans, and the negative impact of anthropogenic noise-induced auditory masking has been reported in several species. We investigated the acoustic variation in 96 males (n = 971 calls) of the treefrog Boana pulchella across acoustically undisturbed sites and different noise conditions, associated with urban areas (URBAN) and roads (ROAD), in Central Argentina. We analyzed the effect of anthropogenic noise conditions on 6 temporal (call duration [CD], intercall interval, first and second note duration, internote interval, and call rate) and 3 spectral (dominant frequency of first and second note, frequency difference between them) call properties. The effects of temperature and size on acoustical variables were controlled. We observed differences in all call attributes among the noise conditions, except for intercall interval. Males exposed to URBAN and ROAD exhibited significant changes in CD, dominant frequency of the second note, and frequency difference between them. URBAN males had longest internote interval, while ROAD individuals displayed increased first and second note duration and call rates. Interestingly, ROAD males exhibited immediate changes in call rate in direct response to passing heavy vehicles. Our study emphasizes the impact of anthropogenic noise on the acoustic characteristics of B. pulchella calls. Understanding how animals adapt to noisy environments is crucial in mitigating the adverse effects of urbanization on their communication systems. Future investigations should explore whether the observed call adjustments are effective in avoiding or mitigating the negative consequences of anthropogenic noise on reproductive success.

Estudantes de fonoaudiologia: autoavaliação da voz, sintomas vocais e diagrama de desvio fonatório / Speech pathologist students: voice self-assessment, vocal symptoms and phonatory deviation diagram / Estudiantes de fonoaudiología: autoevaluación de la voz, síntomas vocales y diagrama de desviación fonatoria

Introdução: considera-se importante que fonoaudiólogos apresentem suas vozes como modelo ao realizar uma intervenção fonoaudiológica. Objetivo: conhecer a autoavaliação da voz e sintomas vocais de um grupo de acadêmicos de fonoaudiologia relacionando os achados ao diagrama de desvio fonatório. Método: estudo do tipo analítico, observacional, com 88 estudantes de Fonoaudiologia de uma mesma faculdade, 82 mulheres e seis homens, média de idade de 21,9 anos, sem diagnóstico de disfonia, autorreferidos saudáveis. Foram registrados e comparados dados relativos à autoavaliação da voz e de sintomas vocais, utilizando-se a Escala de Sintomas Vocais. Numa segunda etapa os estudantes foram convidados a realizar uma análise acústica de suas vozes e os que aceitaram (63,6%) procederam com a coleta das amostras de voz, programa VoxMetria® ­ CTS. Para tratamento dos dados foram utilizados Teste T ­ student e Matriz de Correlações construída com os resultados do Teste T- student (nível de confiança de 95%, alpha 5%). Resultados: a Escala de Sintomas Vocais revelou 44,31% dos participantes com escores brutos igual ou superior a 16 pontos, indicando risco vocal, com maior comprometimento do domínio físico. Alunos do último ano obtiveram escores mais elevados, com predomínio de secreção e pigarro na garganta. Houve correlação positiva entre fumar (7,95%) e aumento da nota final. A análise acústica revelou 40% das vozes com diagrama de desvio fonatório fora do quadrante de vozes normais, irregularidade da voz, jitter e shimmer alterados. Conclusão: a combinação dos dois instrumentos utilizados para conhecimento de risco de disfonia em estudantes de Fonoaudiologia mostra-se relevante e reforça a importância de programas de prevenção de saúde vocal também em futuros fonoaudiólogos. (AU)

Introduction: speech therapists must present their voices as a model for a speech therapy intervention. Objective: to understand the voice self-assessment and vocal symptoms of a group of speech therapy students, relating the findings to the phonatory deviation diagram. Method: an analytical observational study was conducted with 88 speech therapy students from the same college, consisting of 82 women and 6 men, averaging 21.9 years old, who reported no diagnosis of dysphonia, and self-reported as healthy. Data relating to voice self-assessment and vocal symptoms were recorded and compared, using the Vocal Symptoms Scale (VoiSS). In the second stage, students were invited to perform an acoustic analysis of their voices and those who accepted (63.6%) proceeded with the collection of voice samples, using the VoxMetria® ­ CTS program. To process the data, the T-student Test and Correlation Matrix constructed with the results of the T-student Test (confidence level of 95%, alpha 5%) were used. Results: The Vocal Symptoms Scale (student T-test) revealed 44.31% of participants with raw scores equal to or greater than 16 points, indicating vocal risk and greater impairment of the physical domain. Final year students obtained higher scores, with a predominance of secretion and throat clearing. There was a positive correlation between smoking (7.95%) and an increase in the final grade. The acoustic analysis revealed 40% of the voices with a phonatory deviation diagram outside the quadrant of normal voices, voice irregularity, altered jitter, and shimmer. Conclusion: The combination of the two instruments used to understand the risk of dysphonia in speech therapy students is relevant and reinforces the importance of vocal health prevention programs for future speech therapists. (AU)

Introducción: los fonoaudiologos deben presentar su voz como modelo para realizar una intervención logopédica. Objetivo: comprender la autoevaluación vocal y los síntomas vocales de un grupo de estudiantes de fonoaudiología, relacionando los hallazgos con el diagrama de desviación fonatoria. Método: se realizó un estudio observacional analítico, observacional, con 88 estudiantes de fonoaudiología de la misma facultad, conformados por 82 mujeres y 6 hombres, com edad promedio de 21,9 años, quienes no refirieron diagnóstico de disfonia y se autorefiriron como sanos. Los datos relacionados con la autoevaluación de la voz y los síntomas vocales se registraron y compararon mediante la Escala de Síntomas Vocales. En la segunda etapa, los estudiantes fueron invitados a realizar un análisis acústico de sus voces y los que aceptaron (63,6%) procedieron a la recolección de muestras de voz, utilizando el programa VoxMetria® ­ CTS. Para procesar los datos se utilizó la Prueba T de Student y la Matriz de Correlación, construida con los resultados de la Prueba T de Student (nivel de confianza del 95%, alfa 5%). Resultados: La Escala de Síntomas Vocales (prueba T de Student) reveló puntuaciones brutas iguales o superiores a 16 puntos (44,31%), lo que indica riesgo vocal y mayor afectación del dominio físico. Los estudiantes de último año obtuvieron puntuaciones más altas, con predominio de secreción y carraspeo. Hubo correlación positiva entre fumar (7,95%) y aumento en la nota final. El análisis acústico reveló voces presentando diagrama de desviación fonatoria fuera del cuadrante de normaliadad (40%), irregularidad de la voz, jitter y shimmer alterados. Conclusión: La combinación de los dos instrumentos utilizados para comprender el riesgo de disfonía en estudiantes de fonoaudiologia es relevante y refuerza la importancia de los programas de prevención de la salud vocal para futuros fonoaudiologos. (AU)

A High-Speed Acoustic Echo Canceller Based on Grey Wolf Optimization and Particle Swarm Optimization Algorithms.

Currently, the use of acoustic echo cancellers (AECs) plays a crucial role in IoT applications, such as voice control appliances, hands-free telephony and intelligent voice control devices, among others. Therefore, these IoT devices are mostly controlled by voice commands. However, the performance of these devices is significantly affected by echo noise in real acoustic environments. Despite good results being achieved in terms of echo noise reductions using conventional adaptive filtering based on gradient optimization algorithms, recently, the use of bio-inspired algorithms has attracted significant attention in the science community, since these algorithms exhibit a faster convergence rate when compared with gradient optimization algorithms. To date, several authors have tried to develop high-performance AEC systems to offer high-quality and realistic sound. In this work, we present a new AEC system based on the grey wolf optimization (GWO) and particle swarm optimization (PSO) algorithms to guarantee a higher convergence speed compared with previously reported solutions. This improvement potentially allows for high tracking capabilities. This aspect has special relevance in real acoustic environments since it indicates the rate at which noise is reduced.

Seasonal occurrence and individual variability of bull sharks, Carcharhinus leucas, in a marine reserve of the southwestern Gulf of California.

Background: Studying how the bull sharks aggregate and how they can be driven by life history traits such as reproduction, prey availability, predator avoidance and social interaction in a National Park such as Cabo Pulmo, is key to understand and protect the species. Methods: The occurrence variability of 32 bull sharks tracked with passive acoustic telemetry were investigated via a hierarchical logistic regression model, with inference conducted in a Bayesian framework, comparing sex, and their response to temperature and chlorophyll. Results: Based on the fitted model, occurrence probability varied by sex and length. Juvenile females had the highest values, whereas adult males the lowest. A strong seasonality or day of the year was recorded, where sharks were generally absent during September-November. However, some sharks did not show the common pattern, being detected just for a short period. This is one of the first studies where the Bayesian framework is used to study passive acoustic telemetry proving the potential to be used in further studies.

Focusing Surface Acoustic Waves with a Plasmonic Hypersonic Lens.

Plasmonic nanoantennas have proven to be efficient transducers of electromagnetic to mechanical energy and vice versa. The sudden thermal expansion of these structures after an ultrafast optical pulsed excitation leads to the emission of hypersonic acoustic waves to the supporting substrate, which can be detected by another antenna that acts as a high-sensitivity mechanical probe due to the strong modulation of its optical response. Here, we propose and experimentally demonstrate a nanoscale acoustic lens comprised of 11 gold nanodisks whose collective oscillation at gigahertz frequencies gives rise to an interference pattern that results in a diffraction-limited surface acoustic beam of about 340 nm width, with an amplitude contrast of 60%. Via spatially decoupled pump-probe experiments, we were able to map the radiated acoustic energy in the proximity of the focal area, obtaining a very good agreement with the continuum elastic theory.

A Computational Model for the Simulation of Prepulse Inhibition and Its Modulation by Cortical and Subcortical Units.

The sensorimotor gating is a nervous system function that modulates the acoustic startle response (ASR). Prepulse inhibition (PPI) phenomenon is an operational measure of sensorimotor gating, defined as the reduction of ASR when a high intensity sound (pulse) is preceded in milliseconds by a weaker stimulus (prepulse). Brainstem nuclei are associated with the mediation of ASR and PPI, whereas cortical and subcortical regions are associated with their modulation. However, it is still unclear how the modulatory units can influence PPI. In the present work, we developed a computational model of a neural circuit involved in the mediation (brainstem units) and modulation (cortical and subcortical units) of ASR and PPI. The activities of all units were modeled by the leaky-integrator formalism for neural population. The model reproduces basic features of PPI observed in experiments, such as the effects of changes in interstimulus interval, prepulse intensity, and habituation of ASR. The simulation of GABAergic and dopaminergic drugs impaired PPI by their effects over subcortical units activity. The results show that subcortical units constitute a central hub for PPI modulation. The presented computational model offers a valuable tool to investigate the neurobiology associated with disorder-related impairments in PPI.

Accuracy and Cut-Off Values of Cepstral Measures in the Clinical Evaluation of Brazilian Portuguese Speakers.

OBJECTIVE: To identify the accuracy and cut-off values of the cepstral peak prominence (CPP) and cepstral peak prominence-smoothed (CPPS) obtained from different speech tasks, to identify dysphonic voices in Brazilian Portuguese speakers, and to verify the correlation between these measures and the overall severity of dysphonia (OS). METHOD: In a study with 376 subjects-277 with dysphonia and 99 controls-we recorded four speech tasks and assessed OS with a visual analog scale. We extracted CPP and CPPS from these recordings and analyzed them using receiver operating characteristic curves to determine cut-off values and other performance metrics (area under curve, accuracy, sensitivity, specificity, predictive values, and likelihood ratios). RESULTS: CPP values below 28.15 dB (sustained vowel [Ɛ]), 28.77 dB (sustained vowel [a]), 28.58 dB (all Consensus Auditory-Perceptual Evaluation of Voice (CAPE-V) sentences), and CPPS values below 16.42 dB (sustained vowel [Ɛ]), 17.02 dB (sustained vowel [a]), and 11.30 dB (all CAPE-V sentences) are indicative of the presence of dysphonia. CPPVE, CPPVA, CPPCAPE-V, CPPVS, CPPSVE, CPPSVA, CPPSCount, CPPSCAPE-V e CPPSVS, and CPPSVS can explain the variability of OS from 19% to 57.9%. CONCLUSIONS: The cut-off values for CPPVE, CPPVA, CPPCAPE-V, CPPSVE, CPPSCAPE-V, and CPPSVA obtained from Praat software can be used as a reference for the clinical voice assessment of Brazilian Portuguese speakers in the respective speech tasks. Analysis of the correlation coefficients of the cepstral measures investigated provided us with a predictive model of OS perception based on each measure/speech task.

Extensive data engineering to the rescue: building a multi-species katydid detector from unbalanced, atypical training datasets.

Passive acoustic monitoring (PAM) is a powerful tool for studying ecosystems. However, its effective application in tropical environments, particularly for insects, poses distinct challenges. Neotropical katydids produce complex species-specific calls, spanning mere milliseconds to seconds and spread across broad audible and ultrasonic frequencies. However, subtle differences in inter-pulse intervals or central frequencies are often the only discriminatory traits. These extremities, coupled with low source levels and susceptibility to masking by ambient noise, challenge species identification in PAM recordings. This study aimed to develop a deep learning-based solution to automate the recognition of 31 katydid species of interest in a biodiverse Panamanian forest with over 80 katydid species. Besides the innate challenges, our efforts were also encumbered by a limited and imbalanced initial training dataset comprising domain-mismatched recordings. To overcome these, we applied rigorous data engineering, improving input variance through controlled playback re-recordings and by employing physics-based data augmentation techniques, and tuning signal-processing, model and training parameters to produce a custom well-fit solution. Methods developed here are incorporated into Koogu, an open-source Python-based toolbox for developing deep learning-based bioacoustic analysis solutions. The parametric implementations offer a valuable resource, enhancing the capabilities of PAM for studying insects in tropical ecosystems. This article is part of the theme issue 'Towards a toolkit for global insect biodiversity monitoring'.

Time and habitat structure shape insect acoustic activity in the Amazon.

Insects are the most diverse animal taxon on Earth and play a key role in ecosystem functioning. However, they are often neglected by ecological surveys owing to the difficulties involved in monitoring this small and hyper-diverse taxon. With technological advances in biomonitoring and analytical methods, these shortcomings may finally be addressed. Here, we performed passive acoustic monitoring at 141 sites (eight habitats) to investigate insect acoustic activity in the Viruá National Park, Brazil. We first describe the frequency range occupied by three soniferous insect groups (cicadas, crickets and katydids) to calculate the acoustic evenness index (AEI). Then, we assess how AEI varies spatially and temporally among habitat types, and finally we investigate the relationship between vegetation structure variables and AEI for each insect category. Overall, crickets occupied lower and narrower frequency bands than cicadas and katydids. AEI values varied among insect categories and across space and time. The highest acoustic activity occurred before sunrise and the lowest acoustic activity was recorded in pastures. Canopy cover was positively associated with cricket acoustic activity but not with katydids. Our findings contribute to a better understanding of the role of time, habitat and vegetation structure in shaping insect activity within diverse Amazonian ecosystems. This article is part of the theme issue 'Towards a toolkit for global insect biodiversity monitoring'.

A Comparison of Countertenor Singing at Various Professional Levels Using Acoustic, Electroglottographic, and Videofluoroscopic Methods.

INTRODUCTION: The vocal characteristics of countertenors (CTTs) are poorly understood due to a lack of studies in this field. This study aims to explore differences among CTTs at various professional levels, examining both disparities and congruences in singing styles to better understand the CTT voice. MATERIALS AND METHODS: Four CTTs (one student, one amateur, and two professionals) sang "La giustizia ha già sull'arco" from Handel's Giulio Cesare, with concurrent videofluoroscopic, electroglottography (EGG), and acoustic data collection. Auditory-perceptual analysis was employed to rate professional level. Acoustic analysis included LH1-LH2, formant cluster prominence, and vibrato analysis. EGG data was analyzed using FonaDyn software, while anatomical modifications were quantified using videofluoroscopic images. RESULTS: CTTs exhibited EGG contact quotient values surpassing typical levels for inexperienced falsettos. Their vibrato characteristics aligned with expectations for classical singing, whereas the presence of the singer's formant was not observed. Variations in supraglottic adjustments among CTTs underscored the diversity of techniques employed by CTT singers. CONCLUSIONS: CTTs exhibited vocal techniques that highlighted the influence of individual preferences, professional experience, and stylistic choices in shaping their singing characteristics. The data revealed discernible differences between professional and amateur CTTs, providing insights into the impact of varying levels of experience on vocal expression.

Retrosigmoid versus middle fossa approach for hearing and facial nerve preservation in vestibular schwannoma surgery: A systematic review and comparative meta-analysis.

BACKGROUND: Vestibular schwannomas (VS) are benign tumors arising from vestibular nerve's Schwann cells. Surgical resection via retrosigmoid (RS) or middle fossa (MF) is standard, but the optimal approach remains debated. This meta-analysis evaluated RS and MF approaches for VS management, emphasizing hearing preservation and Cranial nerve seven (CN VII) outcomes stratified by tumor size. METHODS: Systematic searches across PubMed, Cochrane, Web of Science, and Embase identified relevant studies. Hearing and CN VII outcomes were gauged using the American Academy of Otolaryngology-Head and Neck Surgery, Gardner Robertson, and House-Brackmann scores. RESULTS: Among 7228 patients, 56 % underwent RS and 44 % MF. For intracanalicular tumors, MF recorded 38 % hearing loss, compared to RS's 54 %. In small tumors (<1.5 cm), MF showed 41 % hearing loss, contrasting RS's lower 15 %. Medium-sized tumors (1.5 cm-2.9 cm) revealed 68 % hearing loss in MF and 55 % in RS. Large tumors (>3cm) were only reported in RS with a hearing loss rate of 62 %. CONCLUSION: Conclusively, while MF may be preferable for intracanalicular tumors, RS demonstrated superior hearing preservation for small to medium-sized tumors. This research underlines the significance of stratified outcomes by tumor size, guiding surgical decisions and enhancing patient outcomes.

The variations of osseous structure of the internal acoustic canal: an anatomical study.

OBJECTIVES: The internal acoustic meatus is an osseous canal that connects the inner ear to the posterior cranial fossa. It is located in the petrous portion of the temporal bone. A thin cribriform osseous plate known as the fundus is situated at the lateral end of the canal. This study assesses the structural and numerical variations of the fundus formations. METHODS: Fifty-four temporal bones of unknown gender and age were examined with the surgical microscope. RESULTS: The temporal bones analyzed were 46.2% right-sided and 53.7% left-sided. Only one temporal bone had two parallel transverse crests, while three had a single anterior crest that split into two branches posteriorly. The number of foramina at the transverse crest varied, with 29.6% having none, 48.1% having a single foramen, and 22.2% having several foramina. An anterior crest structure was seen in 53.7% of the temporal bones, with 5% having a slightly constricted entry to the facial canal. In cases with a single nerve foramen, 48.1% had one, while 51.8% had more than one, including examples with three or four foramina. A crest was found between the foramina of the single nerve in 7% of patients. Furthermore, a crest between the saccular nerve foramen and the high fiber foramina was seen in 25.9% of cases, and 5% had two saccular nerve foramina. CONCLUSION: We think that revealing the anatomical, structural and numerical variations in the fundus will be useful in explaining the disease-symptom relationship. LEVEL OF EVIDENCE: Level 4.