bluuebunny/crossref_metadata_2025 huggingface dataset:
Opportunities and challenges of a community-based bull breeding programme: a case of the regional pastoral livelihood resilience project in Uganda
Authors: Ssekibaala Gonzaga , Ilukor John , Walusimbi Sadhat
Published: October 2024

The Regional Pastoral Livelihood Resilience Project Community-Based Breeding Programme (CBBP) was designed with the objective of increasing production and productivity of local Zebu cattle by introducing Sahiwal bulls among sedentary and agro-pastoral livestock farmers. This study mapped out actors, their roles and level of influence in the CBBP as well as the opportunities and challenges encountered during its implementation using the Process Net-Map tool. The results revealed that there were differences in number and type of influential actors between sedentary and agro-pastoral livestock farmers. The bull host and subcounty veterinary officer were the most influential actors among the sedentary livestock farmers whereas it was the herdsman, bull host, and Community Animal Health Workers (CAHWs) among the agro-pastoral farmers. The CBBP was associated with benefits such as increased market value for cattle, reduced chances for cattle rustling, increased cattle productivity in terms of milk and beef production volumes and ease of access to veterinary services. In contrast, the challenges encountered were related to both governance (limited availability of veterinarians, cattle rustling, exclusion of farmers in the planning phase of the CBBP, political interference and failure of collective action) and bull management (high costs of keeping and maintaining the bulls in terms of feeding, housing, watering and veterinary care, heavy bulls injuring or breaking the small cows, sexually transmitted reproductive diseases among others). Lastly, this paper recommends adoption of a combination of well-organized and facilitated Artificial Insemination (AI) programmes alongside the improved bull service scheme as each has capacity to address the challenges of another.
This Is the Sacrifice: Language, Ideology and Religious Identity Performance in Erei Personal Names
Authors: Uwen God’sgift Ogban , Ukam Edadi Ilem
Published: October 2024

This paper examines personal names derived from traditional religious beliefs and practices among the Erei people in Biase Local Government Area of Cross River State in South-South, Nigeria while utilising insights from the multidisciplinary inferences of socio-onomastic theory to account for the cultural, social and situational contexts that create the religious content of the names. Data were obtained by means of participant observation and semi-structured interviews during six months of fieldwork involving 40 participants who were the name-givers, name-bearers and name-users. Our findings highlight the socio-onomastic tradition of Erei people in which personal names are bestowed through a conscious application of symbolic linguistic resources to express and perform ideologies and identities that are rooted in the traditional religion’s foundations and sociocultural practices that represent Erei people’s indigenous beliefs system and spiritual worldview. Focused on the ideals of African traditional religion, religious identities are constructed through the use of personal names related to idol worship, the mysteries of death, reincarnation and commemoration, cultural festivals and performances, symbolic objects, familial rankings and other aspects derived from their environment that also bear traditional religious significance. And because this set of personal names is now predominant among the ageing population and is losing contemporaneity due to an increasing subpopulation with a new (Christian) beliefs system, this study serves to preserve a transiting and endangered Erei socio-onomastic practice that represents the people’s traditional cosmology.
Coeliac Disease in Children—A Clinical Review Including Novel Treatment Agents
Authors: Corlett Chloe , Rodrigues Astor , Ravikumara Madhur
Published: October 2024

Coeliac disease (CD) affects almost of 1% of the population, yet remains undiagnosed in the majority. Though the demonstration of enteropathy in duodenal biopsy was traditionally the essential criterion for the diagnosis of coeliac disease, the guidelines published by the European Society of Paediatric Gastroenterology and Nutrition (ESPGHAN) in 2012, and revised in 2020, paved the way to a no-biopsy approach to diagnosis. In a select group of children meeting certain criteria, a definitive diagnosis of CD can now be made without the need for duodenal biopsies. This is being increasingly applied in clinical practice. It is well established that untreated coeliac disease is associated with several chronic adverse health conditions. At present, a strict gluten-free diet remains the only effective treatment for CD. The advances in our understanding of the pathogenesis of CD have led to a search for alternative treatment agents. Several investigational agents are in various phases of clinical trials at present. In this review, we outline the clinical aspects of coeliac disease and summarise various investigational treatment agents.
The Antecedents of the Experience of Light in Dreams
Authors: Sparrow Gregory S. , Hurd Ryan
Published: October 2024

The experience of inner light and ecstasy is widely accepted as a universal mystical experience, regardless of cultural or religious context. While one can read first-hand accounts in the historical record, the direct experience of light remains elusive for most people. This study analyzes a series of dream-based experiences of light provided by a single subject. In our analysis of 19 dreams, we pursue a process-oriented, relational analysis based on co-creative dream theory, which views the dream as an interactive experience in real time rather than a fixed product of the unconscious mind. By analyzing dreams as relational events, in which the metaphoric content emerges alongside the dreamer’s responses, we see how the dream ego influences the outcome through feelings, choices, and reactions. Through this analysis, we identify an array of subjective antecedents to the experience of light and provide a potential avenue of access to the core mystical experience.
Perception of audified acoustic emissions from compression of microscopic samples
Authors: DUVAL Florian , XU Clement , LAVANDIER Catherine , PATé Arthur , UGI Dávid , ISPáNOVITY Péter Dusán , KALACSKA Szilvia
Published: October 2024

Recording of acoustic emissions (elastic waves emitted by dislocation motion) during compression of microscopic samples is a novel emerging tool for the investigation of mechanical properties of materials. Yet the resulting signals can be so noisy and complex that they don't easily
allow for identifying the deformation mode or the material involved. This study aims at testing if the human auditory system can pick patterns in the audified recordings (i.e. transposed from the ultrasonic to the audible range) that match the physical characteristics of the samples. In a
Free Sorting Task, participants sorted sounds into groups according to perceived similarity. The sounds originated in recordings varying according to material, deformation mode, and size of the sample. During clustering and multidimensional analysis, sounds were found to be first grouped according
to spectral features: Zinc and Magnesium recordings respectively produced high-pitched and low-pitched sounds. Sounds were further discriminated according to perceived sound level (soft vs. loud for slipping vs. twinning) and number of perceived sound events (no clearly associated physical
parameter). Correlations were found between subjective groupings and audio descriptors, so that audio-inspired mechanical investigations can now be envisioned.
Broadband low-frequency noise attenuation with parallel U-shaped membrane resonators
Authors: KATIYAR Nitish , SARMA CHOUDHURY Sagnik , SAHA Ranamay , BHATTACHARYA Shantanu
Published: October 2024

The attenuation of noise at low frequencies has been the subject of extensive research in the last two decades. Employing membrane-type acoustic metamaterials (MAMs) is one of the most promising solutions due to their lightweight structure and ease of fabrication. This study fabricated
a metamaterial with four U-shaped cavities supporting a thin elastic nitrile rubber membrane. We print the U-shaped cavities using fused deposition modeling (3D printing). The sound absorption coefficient (SAC) is calculated using numerical simulations. For SAC computation, an electro-acoustic
model is developed that constructs an equivalent electrical circuit based on an impedance analogy. Furthermore, the findings of the numerical and analytical analyses are supported by the actual data acquired from the experiments. We have determined that the average sound transmission loss
(STL) is 29.84 dB, and the average SAC exceeds 82% within the frequency range of 500 Hz to 1000 Hz. Due to its lightweight, subwavelength thickness, ability to attenuate broadband noise, and very simple fabrication, this metamaterial is suitable for use in aircraft, automotive industries,
and room/building acoustics.
A review of the application of continuous real-time monitoring in noise risk management
Authors: RAMOSHABA Khanani
Published: October 2024

Background: In the year 2020, the Mineral's Council Chief Executive Officer (CEO) Zero Harm Forum (CEOZHF) reviewed the slow progress towards achieving the 2024 Occupational Health Milestones and agreed that there was a need to improve the current measures in place to reduce occupational
diseases. Following discussions with Group Environmental Engineers, it was proposed to adopt key occupational health indicators for tracking progress through Continuous Real-Time Monitoring (CRTM) to reduce workplace exposures. Methods: A systematic review methodology was employed to gather
data from reputable academic databases. Results: CRTM in Noise Risk Management enables an encompassing practical and intuitive analysis of building noise pollution with prompt alerts for poor acoustic comfort. Real-time graphical display of noise measurements, utilizing a warning signal framework,
facilitated area-specific alerts and responses. Additionally, CRTM enabled the visualization of noise levels and sources through frequency analysis, contributing to noise pollution analysis for zoning and strategic planning in smart cities. Conclusions: While CRTM has been extensively applied
in noise monitoring globally, its utilization in the mining industry, especially in South Africa, remains limited. This study underscores the feasibility of implementing CRTM in Noise Risk Management, emphasizing the need for further research within the mining industry.
Assessment of transparent alternative listening devices' effects on localization cues using head-related transfer function measurements
Authors: PINSONNAULT-SKVARENINA Alexis , BONNET Fabien , NéLISSE Hugues , VOIX Jérémie
Published: October 2024

The past few years have seen a meteoric rise in technological advancements in the hearing health industry. New alternative listening devices, often referred to as "hearables", aim to become real "bionic ears" offering hearing protection, amplification, monitoring
and even biosensing functionalities. With the recent approval of the "Over-the-Counter Hearing Aid Act" in the United States and the introduction of so-called "OTC" hearing aids, these alternative listening devices now have the potential to revolutionize the world of traditional
auditory amplification. Since these devices may be used by individuals with hearing loss, it is important to consider how they might influence spatial auditory awareness. Therefore, this paper studies the effect of alternative listening devices on localization cues using the Head Related Transfer
Function (HRTF). In this purpose, we measured the HRTFs on a Head and Torso Simulator (HATS) with and without digital listening devices. To evaluate the acoustic performance of these devices, the devices were set into their "acoustically transparent" mode. These measures enable a
preliminary characterization of the effect of hearables and OTC devices on localization cues.
Measuring audible acoustic frequencies parameters of rigid porous media via an innovative impedance tube method - Solving the inverse problem
Authors: SADOUKI Mustapha , BENGHERBIA Radhia , MAHIOU Abdelmadjid
Published: October 2024

This study introduces an experimental approach to measuring audible acoustic frequency parameters of a rigid porous medium using an impedance tube. Grounded in the equivalent fluid model, a derivative of Biot's theory, our investigation delves into the propagation of waves within porous
media, emphasizing the importance of effective density and dynamic compressibility of the saturated fluid. Our primary focus is on resolving the inverse problem by minimizing both experimental and theoretical absorption coefficient expressions within the audible frequency range. Concurrently,
we determine four pivotal parameters: viscous and thermal permeability, the inertia factor introduced by Norris, and the thermal tortuosity introduced by Lafarge. The outcomes include a comparative analysis between experimental and simulated absorption coefficients, leveraging optimized parameters,
across two distinct polyurethane foam samples.
Optimisation strategies for indoor acoustic environment in Elderly apartments from a multi-sensory perspective
Authors: MU Jingyi , LI Xuewen
Published: October 2024

As ageing intensifies, the perceptual evaluation of the elderly is increasingly valued. Research has shown that appropriate soundscape can have a positive effect on environmental perception, but current soundscape design in elderly apartments pays more attention to auditory perception
and often neglects the comprehensive impact of multi-sensory. This study was conducted in two elderly apartments in Wuxi and Jinan through physical environment measurements, comparative experiments and questionnaires. The study tested the indoor physical environment and collected the elderly's
perceptual evaluation of each physical environment index. Combined with acoustic and olfactory environment comparative experiments, the study proposed strategies for optimising indoor acoustic and olfactory environment to meet the comfort level of the Chinese elderly. The participants were
aged 70-90 years old and about 100 questionnaires were obtained. The results of the study found that the acoustic environment of elderly apartments, which is mainly based on natural sound, better enhances elderly's perceptual evaluation of the indoor environment; there are differences in the
physical environment needs of older people for different functional rooms.; comfortable odours significantly enhance elderly's overall evaluation of the environment; and different physical environment indexes interact with elderly's perception.
From simulation to reality: tackling data mismatches in speech enhancement with unsupervised pre-training
Authors: CUI JIANQIAO , BLEECK Stefan
Published: October 2024

In this study, we introduce an innovative speech enhancement methodology that ingeniously combines unsupervised pre-training with supervised fine-tuning. This hybrid approach directly addresses the prevalent data mismatch challenge inherent in traditional supervised speech enhancement
methods. Our technique distinctly utilizes unpaired noisy and clean speech data and incorporates varied noises during the pre-training phase. This strategy effectively simulates the benefits of supervised learning, eliminating the need for paired data. Inspired by contrastive learning techniques
prevalent in computer vision, our model is adept at preserving essential speech features amidst noise interference. At the heart of our method lies a sophisticated Generative Adversarial Network (GAN) architecture. This includes a generator that proficiently processes both magnitude and complex-domain
features, alongside a discriminator meticulously designed to optimize specific evaluation metrics. Through rigorous experimental evaluations, we validate the robustness and versatility of our approach. It consistently delivers superior speech quality, demonstrating remarkable efficacy in real-world
scenarios, which are often characterized by complex and unpredictable noise environments.
Sound source characteristics of heat exchanger under flow conditions
Authors: CHEN Wenhua , SUN Yudong , HUANG Weixi , LIANG Yun , LIU Xueguang
Published: October 2024

Heat exchangers are the most important equipment in ship cooling system, which generate vibration and noise due to flow excitation during operation, affecting structural safety and having a significant impact on acoustic stealth performance. Mastering the characteristics of sound source
has guiding significance for noise reduction design. The acoustic signal directly obtained from the hydrophone inside the pipe including reflected sound wave, which cannot accurately characterize the sound radiation energy from heat exchanger into pipe. In order to accurately evaluate the
sound source characteristics of heat exchanger under flow conditions, experimental method was used to test the sound source characteristics of heat exchanger which are not affected by connected pipelines based on the two-port sound source theory. The main factors affecting the sound source
characteristics of heat exchanger were analyzed, such as flow rate, background pressure, and temperature. The research can provide reference for the vibration and noise reduction design of heat exchangers.
Investigating the robustness of interface topological modes in rods
Authors: M. S. RIBEIRO Luiz H. , CLAUS Claus , DANILO Beli , CHRONOPOULOS Dimitrios , ARRUDA J. Roberto F.
Published: October 2024

Topological phononic crystals and metamaterials are structures that can present waveguiding and energy concentration phenomena, which can be of interest in structural dynamics for energy harvesting and passive vibration and noise control. The periodicity of the typical phononic crystals
and metamaterials is broken for these structures, which need to present at least two crystal lattices with different topological characteristics. Thus, the topological invariant, such as the Zak phase, which defines the topological characteristic, must be computed. A rod metastructure exhibiting
two low-frequency band gaps, each with a topological interface mode, was designed. It has bolt sets whose weights generate variability, which was modeled and inferred. In order to increase variability along the rod metastructure, washers were included or removed. Experiments were performed
to validate the simulations. It was observed that the variability of the topological mode in the first band gap is more robust considering its mode shape, natural frequency, and energy concentration at the interface than the second interface mode, at higher frequency. As variability increases,
the robustness of the energy concentration at the interface and of the mode shape of both topological modes decreases. The same behavior was observed for the natural frequencies of the topological modes.
Towards enhanced metamaterials via shape memory alloy-embedded nonlinear resonators
Authors: LOPES Kayc Wayhs , SANTO Douglas Roca , DE OLIVEIRA Leopoldo
Published: October 2024

Standard acoustic metamaterials create an attenuation around specific frequency bands. Finite structures, with distinct boundary conditions and a limited number of unit cells, present less attenuation and narrower bands than those predicted by idealized infinite systems. A critical
engineering goal is enhancing performance to motivate practical applications. To that aim, this work incorporates shape memory alloys into a quasi-zero stiffness resonator design, allowing the tuning of each cell's internal resonance. Such a feature enables the system reconfiguration to achieve
different purposes, from following a disturbance frequency fluctuation to realizing graded nonlinear metamaterials. While the former can work under an adaptive framework, the latter can result in time-invariant locally resonant metamaterials with wideband vibration attenuation. The proposed
design combines a frame that axially compresses an SMA beam in the vicinity of its buckling. The critical buckling force changes by thermally activating the SMA, affecting the residual stiffness, hence the unit cell resonant frequency. The unit cell concept is developed analytically and via
finite elements, then built and validated experimentally. The promising results indicate the viability of the proposed concept. Preliminary numerical simulations and experiments show the advantages of the proposed smart resonator over a linear time-invariant counterpart.
Wind turbine tower dynamic behavior investigation
Authors: TU TSUNG , TU Tsung-Hsien , LO Fang-Chun , KUO Shu-Fen
Published: October 2024

The vibration characteristics of wind turbine may affect the stability, performance and life-time of the system. This research used the theoretical and experimental approaches to predict and investigate the wind turbine dynamic behavior. Three finite element models which were wind turbine
with flow, wind turbine structure only, tower only model and tower and base model, were used to calculated the wind turbine's natural frequencies. The actual measurements were used to validation the model correctness. It is expected used the deformation mode under different external forces,
base conditions for further identify the critical factors for the structural health conditioning of the wind turbine tower.
Applying acoustical criteria to architectural projects
Authors: KARABULUT Seda
Published: October 2024

The requirements for building acoustics should be integrated into the architectural project as early as the preliminary design phase.The materials, densities and thicknesses used in the manufacture of building elements vary from country to country. Therefore, in each country there are
building products with different sound insulation properties resulting from the different characteristics of the building elements. We are developing a local building element database addin for a BIM programme that the architect can easily insert into the project by classifying the sound insulation
properties of the building elements used in Turkey according to their thickness, density and layer properties, which are determined by calculation or measurement. In the future, we plan to integrate additional properties of the building elements, such as fire resistance, sustainability and
cost information, which will facilitate the design of the building.
Conscious walk: integrating soundscape, biodiversity, and air quality metrics for holistic urban environmental assessment
Authors: ALSINA-PAGèS Rosa Ma , PARéS Eulàlia , FREIXES Marc , ARNELA Marc , VIDAñA-VILA Ester , GARCIA Danielly , SERRA Oriol , FERRANDIZ Mariona
Published: October 2024

The impact of environmental noise, poor biodiversity, and air pollution on urban populations poses a significant challenge to public health. Addressing these concerns requires a comprehensive approach that considers the perceptual experiences of citizens and objective environmental
data. The Conscious Walks introduce a hybrid methodology designed to address the perceptive impact of citizens on their environment. Conscious Walks are citizen-science participative projects that combine the active involvement of citizens with scientific data collection. Implemented and tested
in Barcelona, Conscious Walks provide a unique opportunity to assess urban soundscapes, and this contribution specifically evaluates the soundscapes of the Ciutadella Park in Barcelona for three consecutive years. The gathered data is carefully cross-referenced with information on air quality
and biodiversity obtained during the walks. The novelty of this research lies in the development of integrated indicators that comprehensively capture the interplay between biodiversity, noise pollution, and air pollution. These indicators provide an understanding of urban environmental quality,
offering valuable insights for sustainable urban planning and policy-making. The results presented in this contribution underscore the significance of adopting holistic methodologies to address the complex challenges posed by urban environments, emphasizing the need for integrated indicators
in assessing the multifaceted aspects of urban sustainability.
Double-foci acoustic metamaterial Luneburg lens
Authors: ZHAO Liuxian , SUN Zhaoyong
Published: October 2024

In this study, an acoustic Luneburg lens is proposed to achieve double foci. High energy density between the two foci can be obtained, which enables the realization of an ultra long acoustic jet between the two foci. The acoustic Luneburg lens is designed based on the gradient index
acoustic metamaterial with lattice unit cells. Analytical and numerical analyses were performed to investigate the performance of double foci Luneburg lens. Results show that the double foci can be realized with acoustic jet length goes up to 30 times compared with the wavelength, which has
multiple potential applications in medical imaging and energy harvesting.
The use of sound phonons in the development of NVH treatments for light commercial electric vehicles
Authors: HARRY Evan , MORRIS-KIRBY Rod
Published: October 2024

Light Commercial Electric vehicles (LCEV) are becoming increasingly popular due to their environmental benefits and lower operating costs, making them a sustainable choice for businesses looking to reduce their carbon footprint and save fuel expenses. However, unlike Saloon and SUV
electric vehicles LCEV's have to be potentially configured for a wide variety of operating roles including parcel delivery, mini-buses, retail wagons, ambulances and mobile workshops to name just a few. Consequently, when considering their refinement aspects during their development it has
become economically restrictive to base this on actual physical prototypes. Acoustic modelling provides a suitable alternative, but any software package must be highly flexible so that multiple configurations can be examined without requiring time consuming re-modelling. This paper describes
the use of sound phonons in an interactive GUI for the successful development process of an LCEV from target setting through to final optimised NVH package creation. The project involved full vehicle model creation via donor CAD, of a current ICE LCV, which was morphed into an EV to include
an under-floor battery and rear drive system. Sub-system models of areas such as the interior bulkhead, battery pack insulation and EV encapsulation were also integrated during the optimisation process.
Isogeometric vibration analysis of functionally graded material pre-twisted blades with three-dimensional theory
Authors: MINGFEI CHEN Mingfei , ZHOU Jialiang , ZHANG Junxu
Published: October 2024

In this paper, the free vibration characteristics of a rotating functionally graded material (FGM) pre-twisted blades are investigated by the isogeometric method based on the three-dimensional (3D) theory. The effects of Coriolis force, centrifugal softening, and centrifugal rigidity
of the FGM pre-twisted blades are considered in this vibration analysis model. The material properties of the FGM pre-twisted blades are assumed to change continuously along thickness direction. It is easy to satisfy the weak form requirements of the vibration control equation of the FGM pre-twisted
blades by using the NURBS functions. Then, the dynamic equation of the pre-twisted rotating blades can be derived by using the Hamilton's variational principle. Finally, a standard eigenvalue equation is obtained through discretizing equations and expanding dimensions. Numerical examples showed
that the current formulation has fast convergency and good accuracy. Additionally, the influence of installation angle, pre-twisted angle, variable cross-section, material properties and rotating speed on the vibration characteristics of the FGM pre-twisted blades under rotating conditions
is explored in detail. The work can also shed some new lights on the vibration behaviors of pre-twisted blades composite materials.
An investigation of soundscape perception in oncology polyclinics' waiting area based on biophilia hypothesis paradigm: a field and laboratory survey study
Authors: ALIMADHI Enkela , YILMAZER SEMIHA
Published: October 2024

The present study employed an in-between investigation to examine changes in soundscape perception in two waiting areas of Ankara City Oncology assessing both audio-visual environments. For the investigation, a questionnaire survey procedure was employed based on a Biophilia Hypothesis
Paradigm in the field and laboratory. While it is important to establish a baseline from a soundscape perspective within the paradigm, the latter establishes an investigation procedure that claims a positive affective outcome. Important measures for this study are Biophilic Quality using the
Biophilic Interior Design Index (BIDI), Affective Attributes, Sound Overall Quality, Appropriateness, and Sound Source Dominance following ISO/TS 12913-2:2018., Method A. For the visual environment, Visual Appropriateness and Overall Quality were assessed. For the laboratory setting, audio
and visual environments are digitally reproduced using still images and binaural recordings accordingly. Overall, 112 subjects completed the survey considered for further analysis. Significant differences were tested separately with the t-test and Mann-Whitney U test. The biophilic quality
between waiting areas in the field varies from low to moderate biophilic, while the sound descriptors identify an eventful, annoying, monotonous, and chaotic sound environment for both waiting areas and settings based on mean scores.
Are single number ratings for sound insulation requirements still up-to-date?
Authors: NEUBAUER Reinhard O.
Published: October 2024

In general, soundproofing requirements are given in form of a single number rating. Individual values are therefore singular, i.e. precise, so that no uncertainties are taken into account when checking the quality by measurement or calculation. A better description of the quality of
sound insulation would be the formation of classes. In Europe requirements are mainly expressed as a weighted apparent sound reduction index R'w, or by specifying a certain weighted standard sound level difference DnT,w. Both quantities describe a quality that is not necessarily equivalent.
The numerical comparison of the requirements is therefore not or only approximately possible. In light of this consideration requirements should be given therefore by classes. In this paper, the difference between a single number rating and a class rating is discussed.
Numerical validation of a simplified source-receiver mobility approach for estimating building floor velocity responses to railway vibration
Authors: VILLOT Michel , GUIGOU-CARTER Catherine , JEAN Philippe
Published: October 2024

Prediction methods are required for designing buildings to protect inhabitants against ground-borne (structure-borne) sound from railway lines or other outdoor ground vibration sources. There is no European standard for such predictions yet, but a European task group (CEN/TC126/WG2/TG1)
is now doing preliminary work on this subject. A promising approach, based on the source-receiver vibration system methodology (the building foundations being the source and the building upper-structure the receiver) and using a mobility approach, has been identified and presented at Forum
Acusticum in 2023. In the present paper, the approach is numerically validated in a simple 2.5 D configuration (3D but infinite in one direction) of a building along a railway line. The floor velocity responses are estimated first using a numerical BEM model taken as reference model and then
using a simplified mobility approach, where railway excitation is expressed as a line of uncorrelated forces applied to ground and the source-receiver mobility system expressed using effective mobilities (velocity response to a line of uncorrelated forces). The two floor velocity responses
obtained are compared and the assumptions required for easily solving the systems discussed.
Virtual acoustic black holes as a means to achieve low-frequency vibration reduction
Authors: QUAEGEBEUR Samuel , RAZE Ghislain , CHENG Li , KERSCHEN Gaëtan
Published: October 2024

Acoustic black holes (ABH) offer exceptional broadband vibration capabilities but have the inherent drawback of being only effective beyond a specific cut-off frequency. The most straightforward approach to set this threshold to a low value is to increase the ABH length. However, such
a strategy leads to a very thin tip of the ABH, making it very complicated if not impossible to manufacture. Improving this ABH property has been for the past decade an active field of research. Recently, the concept of a virtual acoustic black (VABH) has been proposed by the authors. The
key idea of this approach is to implement digitally the mechanical impedance of the ABH. The virtual feature of this strategy enables the implementation of any kind of ABH (any dimensions, material). Setting the cut-off frequency to low values thus becomes possible. The VABH is implemented
through the use of piezoelectric patches, making it very compact and autonomous. Experimental demonstration shows that the proposed idea is able to mitigate vibration below 100 Hz.
A gateway for access to solutions for underwater radiated noise
Authors: DíAZ José Antonio , DELORY Eric , SUTTON Gerry
Published: October 2024

The SATURN (Solutions AT Underwater Radiated Noise) Virtual Research Environment (VRE) is a gateway for access to products generated by the SATURN project. The SATURN consortium aims to work in harmony with the purpose to identify: a. The sounds that are most detrimental to aquatic
species and how they are produced and propagated. b. The short-term and cumulative long-term negative impacts of noise from shipping and boats on three representative groups of aquatic species in rivers and the sea (invertebrates, fish and marine mammals). c. The most promising options for
measuring and reducing the negative impacts of ship noise that can be applied to current and future vessels. The objective of the present work is to outline some of the products, tools and methodologies of the SATURN Virtual Research Environment which intend to provide solutions and recommendations
for underwater noise mitigation, while integrating the needs expressed by the user community. The SATURN VRE will foster use of data and data products, standardized methods, impact of URN on aquatic life, and solutions to decrease ship noise for usability beyond the project. The environment
will be deployed and hosted by PLOCAN.
Has the German vehicle fleet become quieter? - Results of a measurement campaign using SPB and CPX measurements
Authors: GEBHARDT Jan , KIRCHHOFF Nikolas , MäNNEL Manuel
Published: October 2024

In the past, the German Environment Agency has carried out several measurement campaigns to determine the noise behavior of the German vehicle fleet. The aim of the current project was to identify any trends in comparison to previous campaigns. Autonomous pass-by measurements were carried
out at 30 locations throughout Germany in accordance with DIN EN ISO 11819-1 (SPB) with the aim of recording at least 1000 vehicles per location. As the road surface influences the pass-by noise, near-field measurements according to DIN EN ISO 11819-2 (CPX) were carried out to determine the
homogeneity of the road surface at each measurement location. In parallel to the CPX measurements, texture measurements according to DIN EN ISO 13473 were carried out to quantify the relevant geometric parameters of the road surface. The presentation describes the methodology of these measurements
and presents the final results including a comparison with data from the 2012 and 2002 measurement campaigns.
A sound recognition algorithm to filter non construction site noise
Authors: BIGOT Alexis
Published: October 2024

Sixense Engineering have developed a new algorithm to correct the noise levels measured around construction sites, by identifying and filtering out sounds that are generated by activities outside the site (emergency services sirens, traffic horns, etc.). The idea is to go beyond the
simple classification of audio files by applying the classification algorithm to all the noise events that contribute to the noise dose LAeq,T. In this innovative process, the noise dose is calculated from elementary LAeq,1min,. When noise events are detected (in terms of LAeq,1min), the corresponding
audio recording (.wav file) are analysed by the sound recognition algorithm. When the algorithm identifies that the noise source is not construction related, with a high degree of confidence, the corresponding LAeq,1min is excluded from the noise dose calculation. In other words, the measured
noise dose can be filtered by removing non construction related noise events produced by external sources like sirens, horns, motorbikes, birds, music, etc.
Advanced directional beam control via holographic acoustic metasurfaces for multibeam scanning
Authors: AKRAM Md Tausif , SONG Kyungjun
Published: October 2024

Acoustic multi-beam leaky-wave antennas, designed with holographic metasurfaces, have great potential for beamforming by achieving directional beam control. We propose a planar holographic metasurface for beam steering using multi-beam acoustic radiation serving as high-gain acoustic
leaky wave antennas. Based on the principle of holography, we designed a metasurface that adjusts its admittance in a sinusoidal pattern. This surface consists of periodic cylindrical holes with varying depth profiles. A monopole point source is positioned in the middle of the patterned surface,
which generates surface waves on the modulated surface and emits acoustic leaky-wave radiation in the desired directions. The holographic admittance surface is designed to radiate an acoustic beam at a frequency of 20 kHz. Additionally, the concept was extended to generate multi-beam scanning
for forward leaky-wave radiation in the holographic process. In this research, we employed 3D additive manufacturing to create acoustic holograms, manipulating surface admittance variation at a resolution smaller than the wavelength. The experimental measurements aligned well with both the
theoretical and numerical analysis findings, affirming the effectiveness of the proposed technique. The methodology exhibits broad applicability across various domains, including sonar, ultrasound imaging, waveform manipulation, and acoustic communication.
Exploring the potential of non-traditional sound absorbers to improve acoustic quality in open-plan offices
Authors: OLIVEIRA Marco Aurélio , ANTóNIO Julieta , LEE Pyoung-Jik
Published: October 2024

Open-plan offices are designed to promote collaboration and communication between workers, but they can be noisy and distracting, where irrelevant speech is one of the main causes of dissatisfaction and annoyance. To address the problem, synthetic sound absorbers are often used as one
of the possible acoustic measures. However, these materials are typically derived from petrochemicals, demanding considerable energy for production, which conflicts with global agenda for decarbonization and circularity. Alternatively, non-traditional sound absorbers can replace synthetic
ones, aiming to enhance acoustic quality in open-plan offices. In the present study, a real open-plan office was measured according to ISO 3382-3:2022, and the data was used to calibrate a room model in ODEON. Computer simulations were conducted to evaluate the room with different synthetic
and non-traditional sound absorbers. It was observed that the non-traditional sound absorbers can attenuate office noise as effectively as synthetic sound absorbers, and improve acoustic quality criteria recommended by ISO 22955:2021. Auralizations were then conducted to assess the participants'
auditory perception through a listening test with both types of sound absorbers. The ongoing listening test aims to determine whether the sustainable nature of non-traditional sound absorbers positively influences subjective experiences compared to their synthetic counterparts.
Experiments on sound propagation in forests
Authors: ASTOUL Lucile , SALMON Lola , GLé Philippe , GUILLAUME Gwenaël , PIEGAY Clément
Published: October 2024

Sound propagation in forests poses challenges due to complex factors like ground effects and tree reflections. Limited data on forest sound propagation and bark impedance limit the development of accurate acoustic models. This research addresses this issue by characterizing bark absorption
through laboratory measurements and by studying in-situ sound propagation in a well-documented forest. Objectives include understanding the acoustic behaviours of forest soils and barks, exploring the relevance of existing impedance models, and characterizing sound propagation in wooded areas.
The methodology is based on Kundt's tube measurements for bark absorption and on a defined protocol for forest sound propagation, including in-situ soil impedance measurements. Results will finally enrich reference databases dedicated to, eco-acoustic and soundscape research and will more
generally contribute to a better comprehension of sound propagation in forests.
Acoustic Black Holes ceiling for noise control on board cruise ships
Authors: KYAW OO D'AMORE Giada , BROCCO Emanuele , BIOT Marco , KASPAR Jan
Published: October 2024

Entertainment is one of the principal noise sources on board cruise ships. To ensure high comfort standards in cabins located above public areas, ceilings made by rockwool and honeycomb panels are used as acoustic insulation. Engineers are searching for new solutions to substitute the
traditional system, as the rockwool presents health concerns. Acoustic metamaterials are among the candidates for new products in this field. This paper aims to verify the feasibility of an innovative ceiling design with enhanced Acoustic Black Holes (ABH). The proposed solution is compared
with the traditional ones, using the Sound Reduction (R) as Key Performance Index (KPI). Traditional solutions are experimentally tested, and the data are used to assess an acoustic Finite Element Method (FEM) model, which is then used to simulate the acoustic properties of the proposed ceiling.
Acoustic Black Hole silencers for broadband dissipation in ducted geometries
Authors: BRAVO Teresa , MAURY Cedric , MAZZONI Daniel , AMIELH Muriel
Published: October 2024

The design of novel absorbers avoiding the use of porous or fibrous materials for ventilation and air-conditioning systems constitutes a challenging issue. Recently, the development of metamaterials has provided new noise control perspectives for this problem. Traditional Acoustic Black
Holes (ABHs) have been derived with close-ended configurations to achieve broadband absorption. These solutions are suitable as anechoic termination but they cannot be used as silencer as they require a mean flow going through the axis of the acoustic treatment. In this study different configurations
of opened ABHs will be considered. Nominal ABHs build on straight cavities of increasing depth along the axial direction. To extend the bandwidth of acoustic performance towards the low frequencies, two different types of ABH silencers will be studied. Cavities with coiled geometries will
be considered as a first instance, while the entrance of these cavities will be covered by micro-perforated consequently. The transfer matrix formulation will be adapted to these configurations and used to provide the ABH acoustical performance in terms of reflection and transmission of the
silencer to find out the best configuration. These results will be validated against a Finite Element method and experiments will be carried out for the nominal configuration.
Vibration analysis of piping system coupled with conical-cylindrical combined shells
Authors: WU Jianghai , ZHU Zhen-hui , SUN Yudong
Published: October 2024

Fluid-filled piping system are widely used in power cooling, fuel transportation and underwater vessel, which not only produce vibration along the system, but also transmit to the connecting structure to generate noise in ambient environment. Most investigations have concentrated on
either the vibration characteristics of piping systems or of combined shells separately. In this work, an analytical impedance synthesis method (ISM) is proposed to analyze the vibration characteristics of a pipe-hull coupled system, in which the hull can be simplified to a combined conical-stiffened
cylindrical-hemisphere shell. The piping system is modeled by fluid-filled beams in three-dimensional configuration. Wave function and power series solution are used to describe the displacements of cylindrical and conical shell respectively. Based on exact analytical solutions, the impedance
matrix of each segment is established separately and assembled in the global coordinate by displacement continuity and force balance boundary conditions. Forced responses are compared with the experimental results to verify the correctness of the method.
Estimation of the surface impedance based on the discrete complex image source method and array processing
Authors: BRANDãO Eric , RESENDE Carlos , MAREZE Paulo , FONSECA William , AZZUZ Gabriel , PONTALTI João , FERNANDEZ-GRANDE Efren
Published: October 2024

This paper introduces a method for estimating the sound absorption coefficient of a large panel of absorbing material from measurements using a microphone array. The method relies upon describing the pressure field as the set of monopoles obtained when the reflection coefficient is
represented as the Laplace Transform of an image source distribution. This formulation results in a well-behaved integral equation, which is discretized using Gaussian quadrature to yield an inverse problem. It is possible to determine the regularized solution to the inverse problem and reconstruct
the surface impedance of the sample by conducting measurements of the sound pressure at multiple points of observation. This sound field representation is adequate for sound sources in the close range of the material and the array. The paper presents simulated and experimental investigations
to delineate the efficacy of the proposed measurement technique against the well-known image source method, thereby highlighting its significant potential to advance acoustic characterization methodologies.
Flanking transmission from structure-borne sound sources in heavyweight buildings over multiple junctions
Authors: HOPKINS Carl
Published: October 2024

In many buildings, rooms that contain vibrationally-active machinery are not always adjacent to habitable rooms; hence it is useful to be able to predict vibration transmission over multiple junctions to non-adjacent rooms. In the first version of the European Standard EN 12354 Part
5 (2009) the equivalent vibration reduction index was introduced to account for transmission across multiple junctions. This was removed in the 2023 version but there remains a need for these estimates at the design stage of a building. This paper compares predictions of vibration transmission
from a wall to different receiving rooms in a large heavyweight building. The SEA matrix solution is compared with SEA path analysis using different numbers of paths to assess whether path analysis is feasible, and if so, what errors can be expected when using a limited number of paths. An
alternative approach to path analysis is to use transmission functions for heavyweight buildings, and an initial assessment is made to see whether these are expected to vary significantly depending on the position in the building.