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1.
Sensors (Basel) ; 21(2)2021 Jan 12.
Artigo em Inglês | MEDLINE | ID: mdl-33445499

RESUMO

The factors affecting the penetration of certain diseases such as COVID-19 in society are still unknown. Internet of Things (IoT) technologies can play a crucial role during the time of crisis and they can provide a more holistic view of the reasons that govern the outbreak of a contagious disease. The understanding of COVID-19 will be enriched by the analysis of data related to the phenomena, and this data can be collected using IoT sensors. In this paper, we show an integrated solution based on IoT technologies that can serve as opportunistic health data acquisition agents for combating the pandemic of COVID-19, named CIoTVID. The platform is composed of four layers-data acquisition, data aggregation, machine intelligence and services, within the solution. To demonstrate its validity, the solution has been tested with a use case based on creating a classifier of medical conditions using real data of voice, performing successfully. The layer of data aggregation is particularly relevant in this kind of solution as the data coming from medical devices has a very different nature to that coming from electronic sensors. Due to the adaptability of the platform to heterogeneous data and volumes of data; individuals, policymakers, and clinics could benefit from it to fight the propagation of the pandemic.


Assuntos
Internet das Coisas , Processamento de Sinais Assistido por Computador , Inteligência Artificial , /diagnóstico , Humanos , Oximetria , Pandemias , Espectrografia do Som/métodos , Voz/fisiologia
2.
J Acoust Soc Am ; 149(1): 652, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33514174

RESUMO

Confinement due to the COVID-19 pandemic drastically reduced human activities. Underwater soundscape variations are discussed in this study, comparing a typical and confinement day in a coastal lagoon near a popular tourist city in Mexico. Recording devices were located at 2 m in depth and 430 m away from the main promenade-a two-way avenue for light vehicle traffic-where main tourist infrastructure is located. The nearby marine environment is habitat to birds and dolphins as well as fish and invertebrates of commercial importance. Medium and small boats usually transit the area. The main underwater sound level reduction was measured at low frequencies (10-2000 Hz) because of the decrease in roadway noise. Vessel traffic also decreased by almost three quarters, although the level reduction due to this source was less noticeable. As typical day levels in the roadway noise band can potentially mask fish sounds and affect other low frequency noise-sensitive marine taxa, this study suggests that comprehensive noise analysis in coastal marine environments should consider the contribution from nearby land sources.


Assuntos
/epidemiologia , Monitoramento Ambiental/métodos , Veículos Automotores , Ruído/efeitos adversos , Quarentena/tendências , Animais , Peixes/fisiologia , Humanos , México/epidemiologia , Oceanos e Mares/epidemiologia , Espectrografia do Som/métodos , Espectrografia do Som/tendências
3.
PLoS One ; 15(5): e0233658, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32442214

RESUMO

Most commonly, animal communication systems are driven by shared call repertoires, with some individual distinctiveness encoded as a byproduct of voice cues. We provide evidence that bottlenose dolphins produce both individually distinctive whistles, and a shared whistle type. A stereotyped whistle contour (termed the group whistle) is shared by five bottlenose dolphins that have lived, worked, and traveled together for at least 21 years. These five dolphins are members of a group of eight dolphins that work as a specialized team for the Navy Marine Mammal Program. Each dolphin is routinely recorded during periods when an individual is isolated from the others in above ground pools as part of their routine training. Each of the eight dolphins has an individually distinctive signature whistle. In addition, at least five of these dolphins share a distinct non-signature whistle type. This shared whistle contour was produced an average of 22.4% +/- 9.0% of the time during periods in which individuals were isolated. During these isolations the signature whistle was produced an average of 42.9% +/- 11.9% of the time. This is consistent with decades of signature whistle research. A group of 10 naïve observers rated the similarity of the different whistle contours. The observers rated the group whistle contour produced by all five dolphins as highly similar (P < 0.01). Their ratings further showed that the signature whistles of the five dolphins were very different (P < 0.01). These findings were further supported by discriminant function analyses. That said, the shared whistle contours still exhibited individual differences which may allow conspecifics to identify the producer even when a whistle contour is shared among multiple dolphins. This is the first in-depth analysis of a non-signature whistle type shared among multiple conspecifics.


Assuntos
Golfinho Nariz-de-Garrafa/psicologia , Vocalização Animal , Animais , Feminino , Individualidade , Masculino , Comportamento Social , Espectrografia do Som/métodos , Estereotipagem
4.
PLoS One ; 15(4): e0231484, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32287289

RESUMO

PURPOSE: This study aimed to evaluate the role of motor control immaturity in the speech production characteristics of 4-year-old children, compared to adults. Specifically, two indices were examined: trial-to-trial variability, which is assumed to be linked to motor control accuracy, and anticipatory extra-syllabic vowel-to-vowel coarticulation, which is assumed to be linked to the comprehensiveness, maturity and efficiency of sensorimotor representations in the central nervous system. METHOD: Acoustic and articulatory (ultrasound) data were recorded for 20 children and 10 adults, all native speakers of Canadian French, during the production of isolated vowels and vowel-consonant-vowel (V1-C-V2) sequences. Trial-to-trial variability was measured in isolated vowels. Extra-syllabic anticipatory coarticulation was assessed in V1-C-V2 sequences by measuring the patterns of variability of V1 associated with variations in V2. Acoustic data were reported for all subjects and articulatory data, for a subset of 6 children and 2 adults. RESULTS: Trial-to-trial variability was significantly larger in children. Systematic and significant anticipation of V2 in V1 was always found in adults, but was rare in children. Significant anticipation was observed in children only when V1 was /a/, and only along the antero-posterior dimension, with a much smaller magnitude than in adults. A closer analysis of individual speakers revealed that some children showed adult-like anticipation along this dimension, whereas the majority did not. CONCLUSION: The larger trial-to-trial variability and the lack of anticipatory behavior in most children-two phenomena that have been observed in several non-speech motor tasks-support the hypothesis that motor control immaturity may explain a large part of the differences observed between speech production in adults and 4-year-old children, apart from other causes that may be linked with language development.


Assuntos
Desempenho Psicomotor/fisiologia , Fala/fisiologia , Acústica , Adulto , Antecipação Psicológica/fisiologia , Canadá , Pré-Escolar , Feminino , Humanos , Idioma , Desenvolvimento da Linguagem , Masculino , Fonética , Espectrografia do Som/métodos , Acústica da Fala , Testes de Articulação da Fala/métodos , Medida da Produção da Fala/métodos
5.
PLoS One ; 15(2): e0228892, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32045453

RESUMO

Ultrasonic vocalizations (USV) of laboratory rodents may serve as age-dependent indicators of emotional arousal and anxiety. Fast-growing Arvicolinae rodent species might be advantageous wild-type animal models for behavioural and medical research related to USV ontogeny. For the yellow steppe lemming Eolagurus luteus, only audible calls of adults were previously described. This study provides categorization and spectrographic analyses of 1176 USV calls emitted by 120 individual yellow steppe lemmings at 12 age classes, from birth to breeding adults over 90 days (d) of age, 10 individuals per age class, up to 10 USV calls per individual. The USV calls emerged since 1st day of pup life and occurred at all 12 age classes and in both sexes. The unified 2-min isolation procedure on an unfamiliar territory was equally applicable for inducing USV calls at all age classes. Rapid physical growth (1 g body weight gain per day from birth to 40 d of age) and the early (9-12 d) eyes opening correlated with the early (9-12 d) emergence of mature vocal patterns of USV calls. The mature vocal patterns included a prominent shift in percentages of chevron and upward contours of fundamental frequency (f0) and the changes in the acoustic variables of USV calls. Call duration was the longest at 1-4 d, significantly shorter at 9-12 d and did not between 9-12-d and older age classes. The maximum fundamental frequency (f0max) decreased with increase of age class, from about 50 kHz in neonates to about 40 kHz in adults. These ontogenetic pathways of USV duration and f0max (towards shorter and lower-frequency USV calls) were reminiscent of those in laboratory mice Mus musculus.


Assuntos
Vocalização Animal/classificação , Vocalização Animal/fisiologia , Acústica , Animais , Arvicolinae/crescimento & desenvolvimento , Arvicolinae/metabolismo , Emoções/fisiologia , Feminino , Masculino , Comportamento Social , Espectrografia do Som/métodos , Ondas Ultrassônicas , Ultrassom/métodos
6.
PLoS One ; 15(2): e0228907, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32040540

RESUMO

Rodents' ultrasonic vocalizations (USVs) provide useful information for assessing their social behaviors. Despite previous efforts in classifying subcategories of time-frequency patterns of USV syllables to study their functional relevance, methods for detecting vocal elements from continuously recorded data have remained sub-optimal. Here, we propose a novel procedure for detecting USV segments in continuous sound data containing background noise recorded during the observation of social behavior. The proposed procedure utilizes a stable version of the sound spectrogram and additional signal processing for better separation of vocal signals by reducing the variation of the background noise. Our procedure also provides precise time tracking of spectral peaks within each syllable. We demonstrated that this procedure can be applied to a variety of USVs obtained from several rodent species. Performance tests showed this method had greater accuracy in detecting USV syllables than conventional detection methods.


Assuntos
Roedores/fisiologia , Espectrografia do Som/métodos , Ultrassom/métodos , Vocalização Animal/fisiologia , Acústica , Animais , Bases de Dados Factuais , Feminino , Gerbillinae/fisiologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Muridae/fisiologia , Ratos , Ratos Endogâmicos Lew , Processamento de Sinais Assistido por Computador , Razão Sinal-Ruído , Espectrografia do Som/estatística & dados numéricos , Ultrassom/estatística & dados numéricos
7.
Sensors (Basel) ; 20(2)2020 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-31947639

RESUMO

Heat stress is one of the most important environmental stressors facing poultry production and welfare worldwide. The detrimental effects of heat stress on poultry range from reduced growth and egg production to impaired health. Animal vocalisations are associated with different animal responses and can be used as useful indicators of the state of animal welfare. It is already known that specific chicken vocalisations such as alarm, squawk, and gakel calls are correlated with stressful events, and therefore, could be used as stress indicators in poultry monitoring systems. In this study, we focused on developing a hen vocalisation detection method based on machine learning to assess their thermal comfort condition. For extraction of the vocalisations, nine source-filter theory related temporal and spectral features were chosen, and a support vector machine (SVM) based classifier was developed. As a result, the classification performance of the optimal SVM model was 95.1 ± 4.3% (the sensitivity parameter) and 97.6 ± 1.9% (the precision parameter). Based on the developed algorithm, the study illustrated that a significant correlation existed between specific vocalisations (alarm and squawk call) and thermal comfort indices (temperature-humidity index, THI) (alarm-THI, R = -0.414, P = 0.01; squawk-THI, R = 0.594, P = 0.01). This work represents the first step towards the further development of technology to monitor flock vocalisations with the intent of providing producers an additional tool to help them actively manage the welfare of their flock.


Assuntos
Criação de Animais Domésticos/métodos , Galinhas/fisiologia , Espectrografia do Som/métodos , Máquina de Vetores de Suporte , Vocalização Animal/fisiologia , Bem-Estar do Animal , Animais , Feminino , Transtornos de Estresse por Calor/prevenção & controle , Abrigo para Animais , Umidade , Processamento de Sinais Assistido por Computador , Temperatura
8.
Medicina (Kaunas) ; 55(12)2019 Dec 09.
Artigo em Inglês | MEDLINE | ID: mdl-31835374

RESUMO

Background and objectives: The objective of this study was to contribute to the evaluation of the newborn (NB) cry as a means of communication and diagnosis. Materials and Methods: The study implied the recording of the spontaneous cry of 101 NBs with no intrapartum events (control sample), and of 72 NBs with nuchal cord (study sample) from the "Bega" University Clinic of Obstetrics-Gynecology and Neonatology of Timisoara, Romania. The sound analysis was based upon: Imagistic highlighting methods, descriptive statistics, and data mining techniques. Results: The differences between the cry of NBs with no intrapartum events and that of NBs affected by nuchal cord are statistically significant regarding the volume unit meter (VUM) (p = 0.0021) and the peak point meter (PPM) (p = 0.041). Conclusions: While clinically there are no differences between the two groups, the cry recorded from the study group (nuchal cord group) shows distinctive characteristics compared to the cry recorded from the control group (eventless intrapartum NBs group).


Assuntos
Choro/fisiologia , Cordão Nucal/fisiopatologia , Espectrografia do Som/métodos , Gravação em Vídeo/instrumentação , Algoritmos , Índice de Apgar , Comunicação , Mineração de Dados/métodos , Feminino , Idade Gestacional , Humanos , Recém-Nascido , Gravidez , Romênia/epidemiologia , Software
9.
J Acoust Soc Am ; 146(4): 2466, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31671995

RESUMO

A contrast-enhanced ultrasound (CEUS) imaging approach, termed pulse inversion spectral deconvolution (PISD), is introduced. The approach uses two Gaussian-weighted Hermite polynomials to form two inverted pulse sequences. The two inversed pulses are then used to filter ultrasound (US) backscattered data and discrimination of the linear and nonlinear signal components. A research US scanner equipped with a linear array transducer was used for data acquisition. The receive data from all channels are shaped using plane wave imaging beamforming with angular compounding (from one to nine angles). In vitro data was collected with a tissue mimicking flow phantom perfused with an US contrast agent using PISD and traditional nonlinear (NLI) US imaging as comparison. The role of imaging frequency (between 4.5 and 6.25 MHz) and mechanical index (from 0.1 to 0.3) were evaluated. Preliminary in vivo data was collected in the hindlimb of three healthy mice. Preliminary experimental findings indicate that the PISD contrast-to-tissue ratio was improved nearly ten times compared to the NLI US imaging approach. Also, the spatial resolution was improved due to the effect of deconvolution and spatial angular compounding. Overall, PISD is a promising postprocessing technique for real-time CEUS imaging.


Assuntos
Processamento de Sinais Assistido por Computador , Espectrografia do Som/métodos , Ultrassonografia/métodos , Animais , Meios de Contraste , Membro Posterior/diagnóstico por imagem , Aumento da Imagem , Camundongos , Imagens de Fantasmas
10.
J Acoust Soc Am ; 146(4): 2201, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31672017

RESUMO

This paper aims to present an improved bicoherence spectrum (IBS) combined with cyclic modulation spectrum (CMS) and cross-correlation that is suitable for classification of hydrophone signals involving deep learning (DL). First, the proposed feature utilizes the all-phase fast Fourier transform to modify the spectrum leakage caused by CMS; this can be used to detect line spectra with low signal-to-noise ratios (SNRs). Second, the cross-correlation and bispectrum are both exploited to suppress non-periodic line spectra interference from CMS. Based on numerous numerical simulations and experimental verification, compared with CMS and conventional bispectrum, the prominent characteristics of IBS include: detecting higher-precision periodic harmonics without single-line interference, superior robustness under low SNR, and greatly reducing the data redundancy. In addition, to test the performance of IBS for DL application, three deep belief network (DBN)-based classifiers-DBN-softmax, DBN-support vector machine, and DBN-random forest-are introduced and employed for five experimental scenarios (including ships and underwater source). The results indicate that benefiting from DBN pre-training, the IBS classification accuracy of DBN-based models is generally higher than 80%.


Assuntos
Aprendizado Profundo , Processamento de Sinais Assistido por Computador , Espectrografia do Som/métodos , Análise de Fourier , Ruído , Oceanos e Mares , Razão Sinal-Ruído
11.
IEEE J Biomed Health Inform ; 23(6): 2265-2275, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31478879

RESUMO

Currently, depression has become a common mental disorder and one of the main causes of disability worldwide. Due to the difference in depressive symptoms evoked by individual differences, how to design comprehensive and effective depression detection methods has become an urgent demand. This study explored from physiological and behavioral perspectives simultaneously and fused pervasive electroencephalography (EEG) and vocal signals to make the detection of depression more objective, effective and convenient. After extraction of several effective features for these two types of signals, we trained six representational classifiers on each modality, then denoted diversity and correlation of decisions from different classifiers using co-decision tensor and combined these decisions into the ultimate classification result with multi-agent strategy. Experimental results on 170 (81 depressed patients and 89 normal controls) subjects showed that the proposed multi-modal depression detection strategy is superior to the single-modal classifiers or other typical late fusion strategies in accuracy, f1-score and sensitivity. This work indicates that late fusion of pervasive physiological and behavioral signals is promising for depression detection and the multi-agent strategy can take advantage of diversity and correlation of different classifiers effectively to gain a better final decision.


Assuntos
Depressão/diagnóstico , Eletroencefalografia/métodos , Processamento de Sinais Assistido por Computador , Espectrografia do Som/métodos , Fala/classificação , Algoritmos , Feminino , Humanos , Masculino
12.
Sci Rep ; 9(1): 12182, 2019 08 21.
Artigo em Inglês | MEDLINE | ID: mdl-31434937

RESUMO

The occurrence and distribution of sperm whales in New Zealand waters is mainly known from whaling records or opportunistic sightings by the public and a systematic estimation of the abundance and distribution has never been conducted. In this study, we investigated the foraging activity and occurrence of sperm whales off the Eastern coast of New Zealand using passive acoustic monitoring techniques. Three acoustic recorders were moored to the ocean floor at different locations on the east side of the North and South Island to collect passive acoustic data from June 2016 until August 2017. A total of 53,823 echolocation click trains were recorded and analyzed to understand the spatial and temporal variation of sperm whale foraging activity. No difference in the foraging activity was found between night-time and day-time periods at any of the locations. Click train detections increased toward the south, suggesting increased foraging activity near Kaikoura. At each station, sperm whale foraging activity varied by month.


Assuntos
Ecolocação/fisiologia , Cachalote/fisiologia , Animais , Nova Zelândia , Processamento de Sinais Assistido por Computador , Espectrografia do Som/métodos , Análise Espaço-Temporal , Fatores de Tempo
13.
J Acoust Soc Am ; 145(6): 3467, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31255101

RESUMO

This paper describes song production by the eastern North Pacific right whale (NPRW, Eubalaena japonica) in the southeastern Bering Sea. Songs were localized in real-time to individuals using sonobuoys. Singers whose sex could be determined were all males. Autonomous recorder data from 17 year-long deployments were analyzed to document and characterize song types. Four distinct song types were documented over eight years (2009-2017) at five distinct locations. Each song type consists of a hierarchical structure of 1-3 different repeating phrases comprised predominantly of gunshot sounds; three of the four songs contained additional sound types (downsweep, moan, and low-frequency pulsive call). Songs were detected annually (July-January); all song types remained consistent over eight years. Two different songs often occurred simultaneously, produced by different individuals; the same song was never detected simultaneously at the same location. The same song type was detected on the same day and time at two distant locations, indicating multiple individuals can produce the same song. These findings provide support that males produce song; it remains unknown if females also sing. NPRW is the first right whale species documented to produce song. Based on current knowledge about song in mysticetes, it is hypothesized that these songs are reproductive displays.


Assuntos
Reprodução/fisiologia , Estações do Ano , Som , Vocalização Animal/fisiologia , Animais , Cetáceos , Feminino , Jubarte/fisiologia , Masculino , Canto/fisiologia , Espectrografia do Som/métodos
14.
J Acoust Soc Am ; 145(6): 3289, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31255103

RESUMO

Whistles emitted by Indo-Pacific humpback dolphins in Zhanjiang waters, China, were collected by using autonomous acoustic recorders. A total of 529 whistles with clear contours and signal-to-noise ratio higher than 10 dB were extracted for analysis. The fundamental frequencies and durations of analyzed whistles were in ranges of 1785-21 675 Hz and 30-1973 ms, respectively. Six tonal types were identified: constant, downsweep, upsweep, concave, convex, and sine whistles. Constant type was the most dominant tonal type, accounting for 32.51% of all whistles, followed by sine type, accounting for 19.66% of all whistles. This paper examined 17 whistle parameters, which showed significant differences among the six tonal types. Whistles without inflections, gaps, and stairs accounted for 62.6%, 80.6%, and 68.6% of all whistles, respectively. Significant intraspecific differences in all duration and frequency parameters of dolphin whistles were found between this study and the study in Malaysia. Except for start frequency, maximum frequency and the number of harmonics, all whistle parameters showed significant differences between this study and the study conducted in Sanniang Bay, China. The intraspecific differences in vocalizations for this species may be related to macro-geographic and/or environmental variations among waters, suggesting a potential geographic isolation among populations of Indo-Pacific humpback dolphins.


Assuntos
Golfinhos/fisiologia , Especificidade da Espécie , Vocalização Animal/fisiologia , Animais , China , Razão Sinal-Ruído , Espectrografia do Som/métodos
15.
J Acoust Soc Am ; 145(6): 3595, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31255135

RESUMO

Toothed whales possess a sophisticated biosonar system by which ultrasonic clicks are projected in a highly directional transmission beam. Beam directivity is an important biosonar characteristic that reduces acoustic clutter and increases the acoustic detection range. This study measured click characteristics and the transmission beam pattern from a small odontocete, the spinner dolphin (Stenella longirostis). A formerly stranded individual was rehabilitated and trained to station underwater in front of a 16-element hydrophone array. On-axis clicks showed a mean duration of 20.1 µs, with mean peak and centroid frequencies of 58 and 64 kHz [standard deviation (s.d.) ±30 and ±12 kHz], respectively. Clicks were projected in an oval, vertically compressed beam, with mean vertical and horizontal beamwidths of 14.5° (s.d. ± 3.9) and 16.3° (s.d. ± 4.6), respectively. Directivity indices ranged from 14.9 to 27.4 dB, with a mean of 21.7 dB, although this likely represents a broader beam than what is normally produced by wild individuals. A click subset with characteristics more similar to those described for wild individuals exhibited a mean directivity index of 23.3 dB. Although one of the broadest transmission beams described for a dolphin, it is similar to other small bodied odontocetes.


Assuntos
Ecolocação/fisiologia , Audição/fisiologia , Ultrassom , Vocalização Animal/fisiologia , Acústica , Animais , Golfinhos , Espectrografia do Som/métodos , Stenella
16.
J Acoust Soc Am ; 145(6): 3480, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31255156

RESUMO

Echolocation signals of free-ranging pantropical spotted dolphins (Stenella attenuata) in the western Pacific Ocean have not been studied much. This paper aims to describe the characteristics of echolocation signals of S. attenuata in the northern South China Sea. A six-arm star array with 13 hydrophones was used and a total of 131 on-axis clicks were identified to analyze the acoustic features of the echolocation signals of dolphins. The mean center frequency was 89 ± 13 kHz, with mean peak-to-peak sound source levels of 190 ± 6 dB re: 1 µPa @ 1 m. The mean -3 dB bandwidth and root-mean-square bandwidth were 62 ± 15 kHz and 26 ± 3 kHz, respectively, with mean -10 dB duration of 18 ± 4 µs and root-mean-square duration of 6 ± 2 µs. The results showed that click parameters of S. attenuata in the northern South China Sea are different from those of clicks of the species in Hawaii waters. The differences in click parameters may be due to both behavioral context and/or environmental adaptation of S. attenuata in different habitats.


Assuntos
Ecolocação/fisiologia , Som , Vocalização Animal/fisiologia , Acústica , Animais , China , Golfinhos , Espectrografia do Som/métodos
17.
J Acoust Soc Am ; 145(6): 3351, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31255163

RESUMO

The life history, distribution, and acoustic ecology of the sei whale (Balaenoptera borealis) in the western North Atlantic Ocean remains poorly understood. In this study an array of bottom-mounted recorders captured previously undocumented low frequency 50 to 30-Hz triplet and singlet down sweep vocalizations in close association with signature 82 to 34-Hz sei whale down sweep vocalizations. Spatiotemporal correlations of acoustically tracked sei whales confirm the original vocalizations are produced by sei whales. The 50 to 34-Hz down sweep call types were characterized with a suite of five spectral and temporal measurements. The pattern and repetition of the full acoustic suite is suggestive of song structure and warrants further investigation. The discovery of vocalizations attributed specifically to sei whales enables historic acoustic records to be re-evaluated for the presence of this species throughout its range.


Assuntos
Acústica , Balaenoptera/fisiologia , Vocalização Animal/fisiologia , Animais , Oceano Atlântico , Espectrografia do Som/métodos
18.
Sci Rep ; 9(1): 10997, 2019 07 29.
Artigo em Inglês | MEDLINE | ID: mdl-31358873

RESUMO

Large bioacoustic archives of wild animals are an important source to identify reappearing communication patterns, which can then be related to recurring behavioral patterns to advance the current understanding of intra-specific communication of non-human animals. A main challenge remains that most large-scale bioacoustic archives contain only a small percentage of animal vocalizations and a large amount of environmental noise, which makes it extremely difficult to manually retrieve sufficient vocalizations for further analysis - particularly important for species with advanced social systems and complex vocalizations. In this study deep neural networks were trained on 11,509 killer whale (Orcinus orca) signals and 34,848 noise segments. The resulting toolkit ORCA-SPOT was tested on a large-scale bioacoustic repository - the Orchive - comprising roughly 19,000 hours of killer whale underwater recordings. An automated segmentation of the entire Orchive recordings (about 2.2 years) took approximately 8 days. It achieved a time-based precision or positive-predictive-value (PPV) of 93.2% and an area-under-the-curve (AUC) of 0.9523. This approach enables an automated annotation procedure of large bioacoustics databases to extract killer whale sounds, which are essential for subsequent identification of significant communication patterns. The code will be publicly available in October 2019 to support the application of deep learning to bioaoucstic research. ORCA-SPOT can be adapted to other animal species.


Assuntos
Vocalização Animal , Orca/fisiologia , Acústica , Animais , Aprendizado Profundo , Feminino , Masculino , Redes Neurais de Computação , Som , Espectrografia do Som/métodos
19.
J Acoust Soc Am ; 145(5): EL379, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-31153305

RESUMO

Irregular pitch periods (IPPs) are associated with grammatically, pragmatically, and clinically significant types of nonmodal phonation, but are challenging to identify. Automatic detection of IPPs is desirable because accurately hand-identifying IPPs is time-consuming and requires training. The authors evaluated an algorithm developed for creaky voice analysis to automatically identify IPPs in recordings of American English conversational speech. To determine a perceptually relevant threshold probability, frame-by-frame creak probabilities were compared to hand labels, yielding a threshold of approximately 0.02. These results indicate a generally good agreement between hand-labeled IPPs and automatic detection, calling for future work investigating effects of linguistic and prosodic context.


Assuntos
Fonação/fisiologia , Nível de Percepção Sonora/fisiologia , Percepção da Fala/fisiologia , Qualidade da Voz/fisiologia , Adolescente , Adulto , Feminino , Humanos , Espectrografia do Som/métodos , Fala/fisiologia , Acústica da Fala , Adulto Jovem
20.
J Acoust Soc Am ; 145(5): 3031, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-31153324

RESUMO

Little is known about the vocalizations of Irrawaddy dolphins (Orcaella brevirostris) in the Gulf of Thailand. The present study first described the echolocation clicks of Irrawaddy dolphins in Trat Bay, in the eastern Gulf of Thailand, using a broadband hydrophone system. Over 2 h of acoustic recordings were collected during 14-day study periods in December 2017 and December 2018. Several criteria were used to judge if a click was on axis or as close to the acoustic axis as possible. To calculate the distance of dolphins, a low-budget localization method based on arrival time differences between the direct and indirect signals was used in the present study. The clicks had a mean peak-to-peak source level of 192 ± 3 dB re 1 µPa, an energy flux density source level of 131 ± 3 dB re 1 µPa2s, a mean centroid frequency of 98 ± 10 kHz, a mean duration of 16 ± 2 µs, and a -3 dB bandwidth of 79 ± 13 kHz. The click parameters of the Irrawaddy dolphins in Trat Bay were slightly different from the clicks recorded from the dolphins in Sundarbans, Bangladesh. The present study provided a basic description of the click characteristics of Irrawaddy dolphins in Trat Bay, which could contribute to the management and conservation strategies for local Irrawaddy dolphins, and a basic reference for the proper input parameters in passive acoustic monitoring and detection.


Assuntos
Comportamento Animal/fisiologia , Ecolocação/fisiologia , Vocalização Animal/fisiologia , Acústica , Animais , Golfinhos , Espectrografia do Som/métodos , Tailândia
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