Maximum Fundamental Frequencies Research Articles

Meows of captive feral domestic cats (Felis silvestris catus) in the mating season: acoustic correlates of caller identity and sex

Abstract This study investigates the frequency, temporal and power parameters in 11 (5 males, 6 females) captive feral domestic cats Felis silvestris catus, vocalising in their individual outdoor enclosures during the mating season. Discriminant function analysis (DFA) classified the meows to correct callers with 79.2% accuracy, which exceeded the chance level of 22.9 ± 2.8%, calculated with permutation test. Male meows were lower-frequency, with the maximum fundamental frequency of 0.37 ± 0.05 kHz vs 0.61 ± 0.16 kHz in females. Sex differences in the maximum, beginning and end fundamental frequencies varied from 32 to 39%, depending on acoustic parameter. The DFA classified the meows to correct sex with accuracy of 88.0%, which exceeded the chance level of 58.2 ± 3.1%. We discuss that the meows encode information about individual identity and sex and that acoustic differences in frequency parameters of the meows exceed sexual dimorphism of body size in domestic cat.

Maximisation of Bending and Membrane Frequencies of Vibration of Variable Stiffness Composite Laminated Plates by a Genetic Algorithm

PurposeIn comparison to traditional, constant stiffness laminates, variable stiffness composite laminates (VSCL) with curvilinear fibres represent an extra analysis effort. It is the purpose of this work to present and test a relatively simple optimisation procedure, in order to find the maximum fundamental frequency of vibration in bending and in in-plane vibrations. It is also intended to explain why certain fibre paths lead to higher frequencies.MethodsThe optimisation is performed using a genetic algorithm (GA), which is described in detail. The bending and the in-plane plate models are based on the p-version Finite Element Method. Each model requires a small number of degrees of freedom, an important feature because applying the GA involves the solution of a large number of eigenvalue problems. In order to support the physical interpretation of the optimal designs, mode shapes and stress fields corresponding to some optimal solutions are illustrated.ResultsSingle- and multi-layer plates with different boundary conditions and fibre path types are studied. Fibre paths that lead to maximum fundamental frequencies are found and justified. The consequences that maximising the first frequency has on the higher-order modes of vibration are studied.ConclusionThe proposed optimisation and modelling methods are effective. Curvilinear fibres with the characteristics considered led to the maximum first natural frequency of vibration in a few cases, but not all. Particularly in in-plane vibrations, curvilinear fibres can provide major gains in comparison to straight fibres. The increase in the vibration frequency is accompanied by, overall, larger stresses.

Diagnosis and Management of Vocal Complications after Chondrolaryngoplasty.

Transfeminine patients (transwomen/feminine nonbinary folks assigned male at birth) can undergo chondrolaryngoplasty ("tracheal shave") to feminize their neck appearance. While isolated cases of vocal complications have been reported following the procedure, aggregated outcomes have not been quantitatively studied. We present acoustic and stroboscopic data to describe a patient cohort with vocal complications after chondrolaryngoplasty and discuss reparative surgical technique. Subjective and objective data, including videostroboscopy, were collected from patients with voice complaints after chondrolaryngoplasty. Dislocated anterior commissures were reconstructed with feminization laryngoplasty. Postoperative voice data were recorded and statistically compared to preoperative data using paired t-tests. On consecutive chart review, of the 94 transfeminine women with prior outside history of chondrolaryngoplasty, 27 (29%) reported chronic postoperative hoarseness, deepened pitch, or loss of upper register. On endoscopy, short, lax vocal folds with persistent anterior glottic gap and phase asymmetry were commonly noted; anterior commissure dislocation was confirmed in-office by using needle localization through absent thyroid cartilage. After open resuspension of the anterior commissure with feminization laryngoplasty, post-repair modal-speaking, minimum, and maximum fundamental frequencies (F0) increased on average by 7, 8, and 5 semitones, respectively (p< 0.01), when compared to pre-repair values. On average, perioperative maximum phonation time did not change significantly (p= 0.15). Average self-assessment of vocal femininity increased by 48% (p< 0.01). Anterior commissure dislocation should be suspected with signs of vocal impairment after chondrolaryngoplasty. Following proper diagnosis, resuspension of the anterior commissure via feminization laryngoplasty approach can be an effective reparative technique. This work represents a 2011 OCEBM Level 4 evidence as a case series Laryngoscope, 133:2301-2307, 2023.

Restoration Strategies Following Short-Term Vocal Exertion in Healthy Young Adults.

Purpose This study aims to investigate the effects of a 10-min vocal exertion task on voice and respiratory measures, to determine whether restorative strategies can mitigate these effects after cessation of exertion, and to assess whether these strategies continue to reduce these detrimental effects when vocal exertion is resumed. Method A prospective, repeated-measures design was used. On consecutive days, 20 participants (equal men and women) completed two vocal exertion tasks separated by 10 min of restoration strategies: vocal rest or controlled phonation (low-level tissue mobilization using straw phonation). Voice and respiratory data were collected at baseline, following the first exertion task, after restoration strategies, and after the second exertion task. Outcome measures included (a) vocal effort, (b) phonation threshold pressure, (c) maximum and minimum fundamental frequencies, (d) cepstral peak prominence of connected speech, (e) lung volume initiation and termination, (f) percent vital capacity expended per syllable, and (g) number of syllables per breath group. Results A worsening of phonation threshold pressure (p < .001), vocal effort (p < .001), and increase of minimum fundamental frequency (p = .007) were observed after vocal exertion. Lung volume initiation (p < .001) and lung volume termination (p < .001) increased. These changes were largely reversed by restoration strategies, but only controlled phonation prevented exertion-induced changes in respiratory kinematic measures on a subsequent vocal exertion task. Conclusions Exertion-induced voice changes occur rapidly and may be mitigated by either controlled phonation or vocal rest. Controlled phonation is recommended as a superior strategy due to evidence of a protective effect on a successive vocal exertion task.

Variable Stiffness Composites: Optimal Design Studies

This research work has two main objectives, being the first related to the characterization of variable stiffness composite plates’ behavior by carrying out a comprehensive set of analyses. The second objective aims at obtaining the optimal fiber paths, hence the characteristic angles associated to its definition, that yield maximum fundamental frequencies, maximum critical buckling loads, or minimum transverse deflections, both for a single ply and for a three-ply variable stiffness composite. To these purposes one considered the use of the first order shear deformation theory in connection to an adaptive single objective method. From the optimization studies performed it was possible to conclude that significant behavior improvements may be achieved by using variable stiffness composites. Hence, for simply supported three-ply laminates which were the cases where a major impact can be observed, it was possible to obtain a maximum transverse deflection decrease of 11.26%, a fundamental frequency increase of 5.61%, and a buckling load increase of 51.13% and 58.01% for the uniaxial and biaxial load respectively.

Static and Harmonic Analysis of Winch Shaft using FEM

It is not easy to lift the heavy loads with bare ropes or other components. Winches are very useful for various mechanical applications. In this present work, winch shaft is designed and analysed using Finite Element Method (FEM). Catia and Nastran programs are used for the modelling and analysis. Static and Harmonic analysis are carried out on the winch shaft. In static analysis the maximum displacement induced is .009817 mm, hence based on Rigidity, and stresses in Z-direction are observed to be 0.122E -0.7 mm and 158.731 N/mm2 respectively. The maximum stress and fundamental frequencies found are 119.009 MPa and 143.98 Hz. The deflection value from theoretical calculations is 0.013 mm. The mathematical relations are used for the validation of the analysis and found good agreement.

Effects of prenatal ethanol exposure on acoustic characteristics of ultrasonic vocalizations in rat pups

Rat pups produce ultrasonic vocalizations (USVs) on isolation from their dam. Ultrasonic vocalization is a sensitive tool for evaluating social behavior between pups and their dam. Prenatal ethanol-exposure leads to a reduction in USVs and have the potential of inducing difficulties in social behavior between pups and their dam. However, effects of prenatal ethanol-exposure on the acoustic characteristics of USVs remain unclear. In this study, we recorded USVs produced by rat pups that were prenatally exposed to ethanol and examined their acoustic characteristics. Ethanol was administered to 13 pregnant rats in three stages by gradually increasing concentrations between gestational days (GDs) 8–20. From GDs 14–20, ethanol-containing tap water at concentrations of 30% and 15% (v/v) was administered to the high- and low-ethanol groups, respectively. Tap water without ethanol was given to the control group. On postnatal days (PNDs) 4, 8, 12, and 16, individual newly-born pups were isolated from their dam and littermates and USVs produced by them were recorded for 5 min. The number of USVs in the high-ethanol group was greater than that in both low-ethanol and control groups on PND 12. The mean, minimum, and maximum fundamental frequencies of USVs were elevated in the high-ethanol group compared with that in both low-ethanol and control groups. Higher amplitudes of USVs were produced by male pups in the high-ethanol group than in those in both low-ethanol and control groups on PND 12. These results suggest that prenatal ethanol exposure changed emotionality and accordingly, the high-ethanol group produced more USVs as distress calls.

Buckling and vibration of composite lattice elliptical cylindrical shells

An approach to the finite element study of the buckling and dynamic behaviour of composite lattice cylindrical shells with elliptical cross sections is presented in this paper. The lattice shells are modelled as three-dimensional frame structures composed of curvilinear ribs using beam finite elements. A specialised algorithm is developed to generate the finite element model of the lattice shells based on multiple use of the repeating unit cell of the composite lattice structure. Using this model, the buckling behaviour of the shells subjected to axial loading and transverse bending are investigated. Fundamental frequencies of axial and transverse vibrations of the shells with a massive rigid disk attached to their ends are determined based on the modelling approach proposed in this work. The effects of parameters of the lattice structure on the values of critical buckling loads, buckling and vibration mode shapes, and the fundamental frequencies are examined using parametric analyses. Based on the computations, the angles of orientation of helical ribs delivering maximum critical loads and fundamental frequencies are identified. The results of this study can be applied to the design of the composite tubular bodies of spacecraft made in the form of cylindrical lattice shells with elliptical cross sections.

Acoustic Characteristics of Vocalization Reflecting the States of Discomfort and Comfort in Babies Aged Three and Six Months

We report here the ability of adults to recognize the states of discomfort and comfort in babies aged three and six months by listening to their vocalizations. The acoustic characteristics of vocalizations significant for recognizing states from the characteristics of the baby’s voice are described. Discomfort vocalizations were found to differ from babies’ comfort signals in terms of the mean and maximum fundamental tone frequencies (FTF) and FTF values in the central and final parts of vocalizations. A mathematical model is presented and a function classifying signals as indicating discomfort or comfort is described. Babies’ vocalizations attributed by adults to the comfort and discomfort categories with probabilities of 0.75 and above were very reliably recognized by the mathematical model based on the classification function.

Maximization of fundamental frequencies of axially compressed laminated truncated conical shells against fiber orientation

Free vibration analyses of laminated truncated conical shells subjected to axial compressive forces are carried out by employing the Abaqus finite element program. The fundamental frequencies of these truncated conical shells with a given material system are then maximized with respect to fiber orientations by using the golden section method. Through parametric studies, the influences of the end condition, shell length, shell radius ratio and the compressive force on the maximum fundamental frequencies, the associated optimal fiber orientations and the associated vibration modes are demonstrated and discussed.

Fiber Orientation Angles Optimization for Maximum Fundamental Frequency of Laminated Composite Plates by the Genetic Algorithm and Meshless Method

Fiber orientation angles optimization is carried out for maximum fundamental frequency of clamped laminated composite plates using the genetic algorithm. The meshless method is utilized to calculate the fundamental frequency of clamped laminated composite plates. In the present paper, the maximum fundamental frequency is an objective function; design variables are a set of fiber orientation angles in the layers. The examples of square laminated plates are considered. The results for the optimal fiber orientation angles and the maximum fundamental frequencies of the 2-layer plates are presented.

Tailoring the Fundamental Frequency of Laminated Composite Panels Using Material Properties

Optimization of material properties is performed to maximize the fundamental frequency of the laminated composite panels by means of the genetic algorithm. The global radial basis function collocation method is used to calculate the fundamental frequency of clamped laminated composite panels. In this paper, the objective function of optimization problem is the maximum fundamental frequency; optimization variables are material properties of laminated panels. The results for the optimal material properties and the maximum fundamental frequencies of the 2-layer plates are presented to verify the validity of present method.

Sex and age-class differences in calls of Iberian red deer during the rut: reversed sex dimorphism of pitch and contrasting roars from farmed and wild stags

Stag rutting calls differ among subspecies of red deer Cervus elaphus. Studying sex-, age-, and subspecies-related vocal variation may highlight the forces driving this evolution. This study presents the first bioacoustical comparison of oral calls produced during the rut by Iberian red deer Cervus elaphus hispanicus stags, hinds and calves and compares the acoustics of nasal and oral calls of hinds and calves. Also, it provides the first comparison of rutting roars between farmed and wild stags. Call maximum and mean fundamental frequencies (f0max and f0mean) were higher in farmed than in wild stags. Moreover, hinds had lower f0max and f0mean compared with both farmed and wild stags. The call minimum fundamental frequency (f0min) was indistinguishable between all groups of adults, irrespective of sex, farming and nasal versus oral vocal emission. In calves, but not in hinds, oral calls had higher f0max and f0mean compared with nasal calls. The higher fundamental frequencies in farmed as compared with wild stags may have resulted from emotional arousal due to human presence at recordings or from the higher body conditions of stags reared under a farm. The comparison of our results with previously published data on various subspecies of red deer suggests that there are different pathways of vocal ontogeny in eastern and western branches of Cervus elaphus and that the acoustics of stag and hind calls are more similar within the various subspecies than they are among the subspecies.

Maximization of fundamental frequency of axially compressed laminated curved panels with cutouts

Free vibration analyses of laminated curved panels with central circular cutouts and subjected to axial compressive forces are carried out by employing the Abaqus finite element program. The fundamental frequencies of these composite laminated curved panels with a given material system are then maximized with respect to fiber orientations by using the golden section method. Through parametric studies, the significant influences of the panel aspect ratio, the panel curvature, the cutout size and the compressive force on the maximum fundamental frequencies, the optimal fiber orientations and the associated fundamental vibration modes of these panels are demonstrated and discussed.

Análises perceptivo-auditiva e acústica da voz nos momentos pré e pós fonoterapia de pacientes com falsete mutacional

A disfonia da muda vocal mais comum é o falsete mutacional. Foram analisadas de forma perceptivo-auditiva e acústica as vozes de quatro jovens do gênero masculino com falsete mutacional nas situações pré e pós fonoterapia para apresentar o resultado da intervenção fonoaudiológica. Para coleta dos dados foi solicitado que os pacientes falassem os dias da semana. Quatro fonoaudiólogas avaliaram auditivamente tais emissões por meio dos parâmetros perceptivo-auditivos: grau geral da disfonia, rugosidade, soprosidade, tensão, instabilidade e pitch. As emissões de cada paciente correspondentes aos momentos pré e pós fonoterapia foram apresentadas aos avaliadores aleatoriamente, e os avaliadores não tinham conhecimento prévio da condição da voz analisada (pré ou pós tratamento). A avaliação foi realizada por comparação e os avaliadores deveriam informar se a segunda emissão era melhor, pior ou sem modificação em relação à primeira. Quando houve modificação, deveriam selecionar três parâmetros perceptivo-auditivos referentes à mudança expressiva. Foi informado aos avaliadores somente a idade e o gênero dos pacientes. A frequência fundamental média, assim como a máxima e a mínima foram extraídas de cada emissão dos pacientes utilizando-se o Programa Praat (versão 5132). Foram extraídos e analisados, ainda, os valores de semitom. Os dados foram analisados estatisticamente. Na condição pós fonoterapia os avaliadores consideraram que houve melhora na qualidade vocal de todos os pacientes e foi observada diminuição dos valores da frequência fundamental média, mínima e máxima e nos semitons resultando em um padrão vocal mais grave e estável.

Maximizing the Fundamental Frequency of Laminated Composite Plates with Optimally Shaped Curvilinear Fibers

A new design method is proposed here to maximize the fundamental frequency of laminated composite plates reinforced by curvilinear fibers. Spline functions represent arbitrarily shaped fibers and the Ritz method generates frequency equations. The optimum curvilinear shapes are searched for the maximum fundamental frequencies using a genetic algorithm, and increments of data points which define the spline shape are used as design variables under the limited range of undulation. Comparison of the present analysis method gives good agreement with the finite element method in terms of natural frequencies and vibration modes, and the optimized results show that the present plate with optimally shaped curvilinear fibers gives higher or equal fundamental frequencies than those of conventional plates with optimally oriented parallel fibers.

Pups crying bass: vocal adaptation for avoidance of age-dependent predation risk in ground squirrels?

In most mammals, larger adult body size correlates with lower fundamental frequency and more closely spaced formants in vocalizations relative to juveniles. In alarm whistles of two free-living rodents, the speckled ground squirrel Spermophilus suslicus and yellow ground squirrel S. fulvus, these cues to body size were absent despite prominent differences in body weight and skull and larynx sizes between juveniles and adults. No significant correlations were found between the individual maximum fundamental frequency and body weight, both within age classes and for pooled samples of all animals within species. Furthermore, the mean alarm whistle maximum fundamental frequencies did not differ significantly between age classes (juvenile versus adult) in the speckled squirrel and were even significantly lower in juvenile yellow squirrels. We discuss the hypothesis that the obfuscation of vocal differences between juvenile and adult squirrels may represent a special adaptation of pup vocal behaviour—a form of “vocal mimicry,” resulting in imitation of adult vocal pattern to avoid infanticide and age-dependent predation risk.

Vibration Analysis of Rotating Laminated Cylindrical Shells

Free vibration analyses of rotating laminated cylindrical shells are carried out by the ABAQUS© finite element program. The fundamental frequencies of rotating laminated cylindrical shells with a given material system are then maximized with respect to fiber orientations by using the golden section method. The significant influences of rotating speed, end conditions, shell thickness, shell length, and shell radius on the maximum fundamental frequencies and the associated optimal fiber orientations are demonstrated.

Altruism and recognition in the antipredator defence of deer: 1. Species and individual variation in fawn distress calls

Mule deer, Odocoileus hemionus, females actively defend fawns against predators, including nonoffspring conspecific fawns and heterospecific white-tailed deer, O. virginianus, fawns. We hypothesized that the defence of nonoffspring fawns was due to a recognition error. During a predator attack, females may have to decide whether to defend a fawn with imperfect information on its identity obtained from hearing only a few distress calls. We examined fawn distress calls to determine whether calls made by the two species and by different individuals within each species were acoustically distinctive. The mean and maximum fundamental frequencies of mule deer fawns were nearly double those of white-tailed deer fawns, with no overlap, enabling us to classify 100% of calls to the correct species using a single trait. A large proportion of calls was also assigned to the correct individual using a multivariate analysis (66% and 70% of mule deer and white-tailed deer fawns, respectively, chance = 6% and 10%); however, there was considerable statistical uncertainty in the probability of correct classification. We observed fawns approach conspecific females in an attempt to nurse; females probed most offspring fawns with their noses before accepting them, and always probed nonoffspring fawns before rejecting them, suggesting that close contact and olfactory information were needed to unequivocally distinguish nonoffspring from offspring fawns. Taken together, these results suggest that acoustic variation alone would probably be sufficient to permit rapid and reliable species discrimination, but it may not be sufficient for mothers to unequivocally distinguish their own fawn from conspecific fawns.

Sources of variation in the long-distance vocalizations of spotted hyenas

It has long been recognized that vocal signals communicate information about the age, sex and affective state of callers. However, the mechanisms by which these types of information are communicated are less well understood. Here we investigated variation in the acoustic properties of the long-distance vocalizations, called 'whoops', emitted by free-living spotted hyenas, Crocuta crocuta. Specifically we investigated whether the fundamental frequency, length and rate of whoops provide information about the caller's age, sex and/or level of arousal. We determined the latter by contrasting whoops emitted spontaneously with whoops emitted during periods of social excitement, when callers typically also exhibited visual signals associated with heightened arousal. We found that the minimum fundamental frequency of a whoop provides reliable information about the caller's general age and, for adult callers, information about sex as well. The vast majority of adult male whoop bouts were emitted spontaneously, but juveniles and adult females produced many of their bouts during periods of social excitement. Although context did not significantly affect the whoop bouts of adult females, juvenile bouts emitted during social excitement had higher maximum fundamental frequencies, greater proportions of asymmetric whoop subtypes, and reduced inter-whoop intervals. By reducing the inter-whoop intervals of bouts, juvenile hyenas significantly increased the likelihood that conspecifics would respond to whoops by approaching the caller or its social companion. Peak fundamental frequency and the relative abundance of whoop subtypes did not appreciably affect response. We discuss the potential functions of whooping by juvenile and adult hyenas in light of these findings.