Hasil untuk "Acoustics. Sound"

Francesco Burroni, Sireemas Maspong, James Kirby

This study examines whether Italian geminate consonants influence the fundamental frequency (f0) of adjacent vowels and how such effects interact with voicing-related Cf0 perturbations. Audio and articulatory data from 23 speakers show that vowels following geminates have slightly higher f0 than those following singletons, regardless of voicing. No effect was found on preceding vowels. f0 differences remained stable across speaking rates and articulatory cues. A positive correlation was found between f0 and intensity, consistent with a mechanical, aerodynamic basis for the effect. However, some individual patterns show correlations between f0 and other properties, which may indicate controlled enhancements. The findings are consistent with a hybrid account on which both articulatory contingencies and speaker-specific enhancements may influence co-intrinsic pitch.

Christian E. Stilp, Dawson Stephens

Fast-rate speech can encourage perception of subsequent speech as longer-duration (e.g., longer voice onset time) and vice versa. Bosker, Sjerps, and Reinisch [Sci. Rep. 10(1), 5607 (2020)] suggested that these temporal contrast effects (TCEs) (also known as speaking rate normalization) were immune to selective attention (to one of two simultaneous talkers). However, dichotic presentation of different talkers facilitated perception. Here, trials presented the same talker throughout speaking one sentence diotically, two simultaneous sentences diotically, or those two sentences dichotically before target words. TCE magnitudes were similar across all conditions, which suggests that spatial separation of simultaneous sentences does not shape TCEs.

Lin Chen, Bingzhi Chen, Lulu Chu et al.

Fresh-cut taro, renowned for its high nutritional value and convenience, is prone to rapid browning post-cutting, which hinders its storage life. This study focused on the effects of L-ascorbic acid (AA) combined with ultrasound (US) treatment (AS) on the storage quality and transcriptome analysis of fresh-cut slices of Yongding June Red Taro. Compared to the control (CK) group, AS treatment effectively reduced the weight loss rate of taro slices, maintained higher hardness, delayed the increase of browning, and inhibited the accumulation of O2− and H2O2. Furthermore, the AS group showed increased glutathione levels and maintained higher activities of ascorbate peroxidase and glutathione reductase, yet decreased the contents of flavonoids and reducing sugars. Simultaneously, in the AS group, the activities of tyrosinase and lipoxygenase were lowered, thereby preserving the high sensory quality of fresh-cut taro slices. Transcriptome analysis revealed that differentially expressed genes (DEGs) between the AS and CK groups were annotated and categorized into 50 and 20 functional groups based on the Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) databases, respectively. Notably, both groups exhibited significant enrichment in processes related to photosynthesis, protein processing in the endoplasmic reticulum, and isoflavone biosynthesis. Therefore, we concluded that AS treatment could alleviate oxidative stress and maintain storage quality by regulating metabolic pathways. These findings provide insights into the physiological changes occurring in taro immediately after cutting and serve as an essential basis for developing effective storage and preservation techniques.

Banerjee Pragyan, Ojha Shivam, Kalimullah Nur M. M. et al.

This paper presents an approach to overcome the time-intensive nature of the Coulomb coupling imaging method by employing Generative Adversarial Networks (GANs) for data augmentation. Coulomb coupling, an experimental technique, is essential for visualizing ultrasonic wave propagation in piezoelectric materials and is valuable in various domains including materials research. It provides valuable insights such as finding mechanical properties and detecting anomalies in piezoelectric materials. However, the efficiency of this method is hindered by traditional time expansive point-by-point scanning. Integrating advanced machine learning into Coulomb coupling imaging has emerged as a promising solution to address this issue. Nonetheless, the lack of sufficient data has been a significant challenge. The key contribution is the use of GANs to create synthetic yet realistic images from a limited set of real data, effectively overcoming the issue of data scarcity. A large number of artificial images were successfully generated, expediting model training and enhancing generalization. This study is the first to use GANs in Coulomb coupling imaging, showing its transformative potential. By overcoming data limitations, the proposed approach enhances Coulomb coupling imaging and enables its integration with advanced technologies like AI-driven predictive modeling and real-time adaptive imaging. This opens new frontiers for applications in materials science and other imaging modalities.

Schmidt Thorsten, Müller Dirk

Heat pumps represent an essential component of the energy transition. While they are effective in generating heat, they also generate sound, which has the potential to cause annoyance. Therefore, it is essential to enhance the transparency of the sound behavior. Analyses were performed to identify the factors that influence sound levels at the component and system levels. A total of three refrigerant compressors were examined with the objective of determining the most acoustically efficient components currently available and the key factors influencing acoustics. Two low-noise axial fans are used to illustrate the differing sound characteristics when used in a heat pump application. Based on component tests and measurements at the heat pump system level, the speeds of the compressor and fan were confirmed as significant factors influencing the sound emissions of air-to-water heat pumps. In addition, the flow temperature and the operating point of the fan were identified as factors influencing. The results were employed to develop an acoustically improved heat pump demonstrator, which was based on a representative design. A sound model could be developed that is capable of describing the sound behavior for a wide range of operating conditions. This methodology allows for increased transparency in sound behavior. Different sound behaviors of heat pumps can be demonstrated on the basis of the model, and discussions on the definition of maximum sound specifications can be held on the basis of data. Sound emissions should not only be linked to heat output, as this increases the uncertainty of comparability. A transparent representation of the speeds is strongly recommended.

Yu Ogura, Keita Taniya, Takafumi Horie et al.

This study synthesized UiO-66, a typical Zr-Metal Organic Framework (MOF), by using an ultrasound-assisted synthesis method to reduce the synthesis time. This method was short-time ultrasound irradiation at the initial stage of the reaction. As compared with average particle size of conventional solvothermal method (=192 nm), averaged particle size by the ultrasound-assisted synthesis method showed particle sizes that were smaller on average, ranging from 56 to 155 nm. In order to compare the relative reaction rates of the solvothermal method and the ultrasound-assisted synthesis method, the cloudiness of the reaction solution in the reactor was observed with a video camera, and the luminance was calculated from the images obtained by the video camera. It was found that the ultrasound-assisted synthesis method showed a faster increase in luminance and shorter induction time than the solvothermal method. The slope of the luminance increase during the transient period was also found to become increase with the addition of ultrasound, which also affects the growth of particles. Observation of the aliquoted reaction solution confirmed that particle growth was faster in the ultrasound-assisted synthesis method than in the solvothermal method. Numerical simulations were also performed using MATLAB ver. 5.5 to analyze the unique reaction field generated by ultrasound. Bubble radius and temperature inside a cavitation bubble was obtained using the Keller-Miksis equation, which reproduces the motion of a single bubble. The bubble radius expanded and contracted repeatedly according to the ultrasound sound pressure, and eventually collapsed. The temperature at the time of collapse was extremely high, exceeding 17,000 K. It was confirmed that the high-temperature reaction field generated by ultrasound irradiation promoted nucleation, leading to a reduction in particle size and induction time.

Dui Qin, Qingqin Zou, Xianhua Zhong et al.

Due to its physical and/or chemical effects, acoustic cavitation plays a crucial role in various emerging applications ranging from advanced materials to biomedicine. The cavitation bubbles usually undergo oscillatory dynamics and violent collapse within a viscoelastic medium, which are closely related to the cavitation-associated effects. However, the role of medium viscoelasticity on the cavitation dynamics has received little attention, especially for the bubble collapse strength during multi-bubble cavitation with the complex interactions between size polydisperse bubbles. In this study, modified Gilmore equations accounting for inter-bubble interactions were coupled with the Zener viscoelastic model to simulate the dynamics of multi-bubble cavitation in viscoelastic media. Results showed that the cavitation dynamics (e.g., acoustic resonant response, nonlinear oscillation behavior and bubble collapse strength) of differently-sized bubbles depend differently on the medium viscoelasticity and each bubble is affected by its neighboring bubbles to a different degree. More specifically, increasing medium viscosity drastically dampens the bubble dynamics and weakens the bubble collapse strength, while medium elasticity mainly affects the bubble resonance at which the bubble collapse strength is maximum. Differently-sized bubbles can achieve resonances and even subharmonic resonances at high driving acoustic pressures as the elasticity changes to certain values, and the resonance frequency of each bubble increases with the elasticity increasing. For the interactions between the size polydisperse bubbles, it indicated that the largest bubble generally has a dominant effect on the dynamics of smaller ones while in turn it is almost unaffected, exhibiting a pattern of destructive and constructive interactions. This study provides a valuable insight into the acoustic cavitation dynamics of multiple interacting polydisperse bubbles in viscoelastic media, which may offer a potential of controlling the medium viscoelasticity to appropriately manipulate the dynamics of multi-bubble cavitation for achieving proper cavitation effects according to the desired application.

P. Bottalico, J. Codino, L. C. Cantor-Cutiva et al.

INTRODUCTION Computer analysis of voice recordings is an integral part of the evaluation and management of voice disorders. In many practices, voice samples are taken in rooms that are not sound attenuated and/or sound-proofed; further, the technology used is rarely consistent. This will likely affect the recordings, and therefore, their analyses. OBJECTIVES The objective of this study is to compare various acoustic outcome measures taken from samples recorded in a sound-proofed booth to those recorded in more common clinic environments. Further, the effects from six different commonly used microphones will be compared. METHODS Thirty-six speakers were recorded while reading a text and producing sustained vowels in a controlled acoustic environment. The collected samples were reproduced by a Head and Torso Simulator and recorded in three clinical rooms and in a sound booth using six different microphones. Newer measures (eg, Pitch Strength, cepstral peak prominence, Acoustic Voice Quality Index), as well as more traditional measures (eg Jitter, Shimmer, harmonics-to-noise ratio and Spectrum Tilt), were calculated from the samples collected with each microphone and within each room. RESULTS The measures which are more robust to room acoustic differences, background noise, and microphone quality include Jitter and smooth cepstral peak prominence, followed by Shimmer, Acoustic Voice Quality Index, harmonics-to-noise ratio, Pitch Strength, and Spectrum Tilt. CONCLUSIONS The effect of room acoustics and background noise on voice parameters appears to be stronger than the type of microphone used for the recording. Consequently, an appropriate acoustical clinical space may be more important than the quality of the microphone.

Xiaolan Li, Zhi-Hong Zhang, Jiaqi Qiao et al.

Natural betalains can be potential food additives because of their antioxidant activities, but they have poor thermal stability. In this study, betalains were extracted from red dragon fruit peel, and then encapsulated with maltodextrin by ultrasound method to increase the physicochemical properties of betalains microcapsules. The encapsulation efficiency of the betalains was above 79%, and the particle size and Zeta potential values were 275.46 nm and −29.01 mV, respectively. Compared to the control sample, onset temperature and DPPH free radical scavenging of betalains microcapsules under the modest ultrasound treatment (200 W, 5 min) was increased by 1.6 °C and 12.24%, respectively. This increase could be due to the ability of ultrasonification to create interactions between maltodextrin and betalains (as evidenced by FT-IR). Therefore, modest ultrasound treatment can be used for microcapsulation to improve the stability of betalains, and then expand the application of betalains in heat processed food field.

Sanjay Kumar, H. Lee

In the past two decades, acoustic metamaterials have garnered much attention owing to their unique functional characteristics, which are difficult to find in naturally available materials. The acoustic metamaterials have demonstrated excellent acoustical characteristics that paved a new pathway for researchers to develop effective solutions for a wide variety of multifunctional applications, such as low-frequency sound attenuation, sound wave manipulation, energy harvesting, acoustic focusing, acoustic cloaking, biomedical acoustics, and topological acoustics. This review provides an update on the acoustic metamaterials’ recent progress for simultaneous sound attenuation and air ventilation performances. Several variants of acoustic metamaterials, such as locally resonant structures, space-coiling, holey and labyrinthine metamaterials, and Fano resonant materials, are discussed briefly. Finally, the current challenges and future outlook in this emerging field are discussed as well.

J. Trusler

FLUID PROPERTIES FROM THE SPEED AND ABSORPTION OF SOUND Introduction Thermodynamic properties from the speed of sound Kinetic information from the speed and absorption of sound Transport properties from sound absorption at a surface FUNDAMENTAL THEORY Introduction Propagation in an idealized fluid Propagation in a dissipative fluid Boundary conditions CAVITIES Introduction The normal modes of an acoustic cavity Forced oscillations Boundary conditions The parallelepiped The cylindrical cavity The spherical enclosure The high frequency interferometer RELAXATION PHENOMENA Introduction Translational relaxation Molecular thermal relaxation Chemical and structural relaxation GENERATION AND DETECTION OF SOUND Introduction Radiation from point and piston sources Vibrating elements The piezoelectric effect Capacitance transducers Moving-coil transducers Photoacoustic excitation Waveguides EXPERIMENTAL METHODS 1: STEADY-STATE TECHNIQUES Introduction The single-transducer interferometer The double-transducer interferometer Spherical resonators Cylindrical resonators Numerical methods Choice of methods EXPERIMENTAL METHODS 2: TRANSIENT TECHNIQUES Introduction Pulse methods Reverberation methods APPENDICES

Shoichi Koyama, G. Chardon, L. Daudet

In order to control an acoustic field inside a target region, it is important to choose suitable positions of secondary sources (loudspeakers) and sensors (control points/microphones). This article provides an overview of state-of-the-art source and sensor placement methods in sound field control. Although the placement of both sources and sensors greatly affects control accuracy and filter stability, their joint optimization has not been thoroughly investigated in the acoustics literature. In this context, we reformulate five general source and/or sensor placement methods that can be applied for sound field control. We compare the performance of these methods through extensive numerical simulations in both narrowband and broadband scenarios.

A. Can, Alain L'Hostis, P. Aumond et al.

Abstract The degradation of the sound environment contributes significantly to the external costs of mobility and is an obstacle to the development of cities. Action plans aiming at fighting traffic noise often take a long time to reach mature implementation. Therefore, it is advantageous to envisage how societal and urban changes and associated changes in mobility practices will modify the urban sound environment of tomorrow. In this article, an interdisciplinary team of seven researchers, whose work focuses on different fields of acoustics and mobility, reviews the potential impact of ongoing mobility and society changes on sound environments. First, the team identified the trends dealing with urban renewal, societal changes and new mobility drivers that have the greatest influence on sound environments, and analyzed in detail. From this analysis, insights emerged for urban noise impact and innovative noise mitigation solutions in the light of improved assessment of the links between mobility and urban sound environments.

Elena Desiderà, P. Guidetti, P. Panzalis et al.

Assessing fish biodiversity patterns is a major concern in aquatic science and conservation. To be effectively used, fish diversity assessments benefit from the use of integrated complementary approaches. Passive acoustics has received increasing attention as a non-invasive, long-term monitoring tool, as it uses biological sounds produced incidentally or intentionally as natural tags to identify and estimate animal diversity. In the marine environment, there is little evidence about the link between taxonomic diversity (different species) and acoustic diversity (different sound types). Here we used underwater visual census fish data collected over multiple years from 3 sites within a Mediterranean Marine Protected Area as comprehensive information on local fish assemblages to be compared with acoustic recordings obtained in September 2015. Richness, diversity and community similarity indices as well as abundance analyses revealed a strong relationship between taxonomic diversity and acoustic diversity. Overall, acoustic communities showed pronounced differences between the study sites that were not

Randall P. Wagner, Richard A. Allen, Qian Dong

A precision laser-based comparison calibration method for laboratory standard microphones is described that uses reference microphones calibrated by the pressure reciprocity method. Electrical drive current and diaphragm velocity are measured while the microphones are driven as transmitters/sources of sound; the diaphragm velocity is measured using scanning laser Doppler vibrometry. Sensitivities determined using this method display very good agreement with those determined directly by reciprocity for seven such test microphones at 250 and 1000 Hz. At these frequencies, the expanded (coverage factor k = 2) uncertainties of this comparison calibration method for these microphones are ±0.05 dB.

Hanyang Gao, Kunkun Pei, Dong Lei et al.

Due to the tunability in mass transfer, solvation and solubility, gas-expanded liquids show advantages over traditional organic solvents in many characteristics. Ultrasonication is a commonly used method to promote heat and mass transfer. The introduction of ultrasonic technology into the gas-expanded liquid system can promote the polymerization of polymer monomers, enhance extraction efficiency, and control the growth size of nanocrystals, etc. Although acoustic cavitation has been extensively explored in aqueous solutions, there are still few studies on cavitation in organic liquids, especially in gas-expanded liquid systems. In this article, the development of cavitation bubble cloud structure in CO2-expanded N, N-dimethylformamide (DMF) was observed by a high-speed camera, and the cavitation intensity was recorded using a spherical hydrophone. It was found that the magnitude of the transient cavitation energy was not only related to input power, but also closely related to CO2 content. The combination of ultrasound (causing a rapid alternation of gas solubility) and gas-expanded liquid system (causing a decrease in viscosity and surface tension of liquids) is expected to provide a perfect platform for high-speed mass transfer.

Jessica L. Gaines, Kwang S. Kim, Benjamin Parrell et al.

The Maeda model was used to generate a large set of vocoid-producing vocal tract configurations. The resulting dataset (a) produced a comprehensive range of formant frequencies and (b) displayed discrete tongue body constriction locations (palatal, velar/uvular, and lower pharyngeal). The discrete parameterization of constriction location across the vowel space suggests this is likely a fundamental characteristic of the human vocal tract, and not limited to any specific set of vowel contrasts. These findings suggest that in addition to established articulatory-acoustic constraints, fundamental biomechanical constraints of the vocal tract may also explain such discreteness.

Li Wang, F. Tian

Abstract The fluid–structure–acoustics interaction of flexible flapping wings is numerically studied by using an immersed boundary method at a Mach number of 0.1. In this study, a wing flapping in a uniform flow with prescribed leading edge motion is considered. Apart from rigid wings, flexible wings of various bending rigidities and mass ratios are also examined. By using a direct numerical simulation technique, the sound generation mechanism is identified. The numerical results show that the wing with combined translational and rotational motion generates smaller sounds than the translating wing, and larger rotational angles transform the dipole sound to a monopole one. Similar sound fields are observed among all these wings, except that the direction of the sound shifts to the downstream for large flexible wings. Frequency analysis shows that the sound is dominated by the flapping frequency and two times of the flapping frequency in the vertical and horizontal directions, respectively. The results also show that the thrust increases first then decreases with bending rigidity for all three mass ratios considered, and the lighter wing suffers more decrease. However, the fluctuating pressure for the three mass ratios varies significantly. Specifically, it increases significantly with the decreasing bending rigidity when the structural inertia is dominating at m ∗ = 5 . 0 ; but it experiences a reduction contrarily when the aerodynamics becomes dominant at m ∗ = 0 . 5 ; for the medium mass ratio at m ∗ = 1 . 0 , no significant effects are observed. The comparisons indicate that the flexible wing with a lower mass ratio (e.g. m ∗ = 0 . 5 ) and a medium flexibility (e.g. ω ∗ = 0 . 3 ) achieves lower sound generation without significant thrust decrease. In addition, the sound on the windward side is pronounced significantly when the wing is flapping with a stroke plane angle less than 9 0 o . The present results can expand the currently limited database of fluid–structure–acoustics interaction, and also provide an insight for the optimization of flight vehicle using flapping wing.

Audiovideo Interiors

ore than three-quarters of the teachers in a recent poll gave the acoustics in their classrooms a failing grade. The problem is most commonly a "signal to noise" ratio issue, which results in poor speech intelligibility. In lay terms, the room is too noisy and it takes a long time for sound to decay within the room. Studies by Maxwell and Evans (1997) .... '" ~ .... ~~........I have shown that students in schools with high background J: u "'. noise levels tested lower than students in schools with lower '" Q. ::> a background noise levels. '" '" Recently, the American National Standards Institute (ANSI) '" e'i ell approved a new set of recommended acoustical specifica­ Z .... '" '" tions for schools (ANSI 512.60-2002). "The criteria, require­ '" :I: .... ments, and guidelines of this Standard are keyed to the >­ ell a acoustical qualities needed to achieve a high degree of .... a :I: speech intelligibility in learning spaces," according to Paul Q.

Özay Önal

In this research, the concept of sound in Turkish has been considered in terms of its occurrences in the fields of music and speech and analyzed in the related metalanguage and daily language. As it is the case for most conceptual field, we have a body of structured knowledge regarding the sound. It is understood from the image schematic, conceptual metaphorical and metonymic patterns found in music and phonology texts that the components of the sound like pitch, amplitude and timbre; and the formations of it like melody, motion, path, interval, chord and scale are understood as abstract concepts that must be embodied as concrete entities by the human mind. Drawing on this, the roles of these patterns in structuring the conceptual content of the sound in Turkish frame the focus of this research. To that end, typical examples have been collected from the metalinguistic usages found in the books of music theory, linguistics, acoustics and music encyclopedias. On the other hand, naïve knowledge models of sound have been observed in daily formulaic language containing idioms and proverbs and also in the web news. Findings show that image schemas, conceptual metaphor and metonymy are highly prevalent in both models of knowledge. In addition, it has been observed that the specific terms found in the metalanguage of music and linguistics actually belong to the vernacular and they have been transferred into the metalanguage through metaphorical mapping. Scientific/expert models, which contain metalanguage rich in field terms and naïve/folk models, which are owned by ordinary people