bluuebunny/crossref_metadata_2025 huggingface dataset:
Evidence-Based Recommendations for Effective Enrichment to Improve the Welfare of Caged Hens Used for Research and Teaching Purposes
Authors: Moss Amy F. , Northey Rebel , Sukirno  , Nawab Aamir , Akter Nasima , Taylor Peta S. , Dao Hiep Thi
Published: October 2024

Currently, there are no guidelines on housing or recommendations for practical environmental enrichments for chickens used for research and teaching purposes. This study was conducted to identify optimal enrichment programs to improve the health and welfare of caged hens used for teaching and research purposes. The 24-week-old Hy-line Brown laying hens (n = 168) were allocated at random to six enrichment programs/treatments with 14 replicate cages of two birds per cage during a 5-week experiment. Hens had physical access to the following treatments: no enrichment provided (control); round, wooden perches provided (perch); scratch pads made of wood and covered with sandpaper provided (scratch pad); hanging CDs provided (hanging CD); all three enrichment forms provided (complex environment); and each enrichment form provided on a 2-week rotation (novelty). While the egg quality was consistent, the complex group had a significantly lower feed intake (p < 0.001) but similar egg mass; thus, they also had a lower feed conversion ratio (p < 0.001). Additionally, hens in the complex treatment group had the leanest average body weight at week 5 (p < 0.01). It should be noted that while some measures of welfare did show significant differences, the biological or practical difference may be negligible, as in the case of the body condition score in this study. The results show that providing three different forms of environmental enrichment had positive effects on the welfare, health condition, and laying performance of laying hens relative to no enrichment or only one enrichment item.
Sound insulation in different kinds of offices - what is needed for different situations
Authors: LARSEN Bernt Mikal
Published: October 2024

Some kind of working groups like doctors, priesthood and lawyers are dealing with confidential and personal information in their daily life. In general there is a need to hinder personal information to be spread more than necessary. With loud level of conversation in pressed situations,
R'w of minimum 48 dB is needed to hinder spreading of sensitive information to neighbor room. The paper will discuss different concepts for offices like office landscape, client-zone, and when and why proper sound insulation is necessary. There are also other buildings where proper sound insulation
is needed between offices, like offices and meeting rooms in schools, kindergarten, social welfare services, banking services, insurance companies and house for family counseling or health care. It is a big need to clarify sound insulation in office buildings or administration rooms based
on what kind of conversations are going on or what kind of information are being dealt with. The boundary between necessary sharing of information for proper internal discussion and unnecessary spreading is important issue to consider. Experience shows that duty of confidentiality for employees
is not sufficient to hinder spreading of sensitive information.
Selection of the averaging time for the interrupted noise method of measuring reverberation time
Authors: DAVY John
Published: October 2024

The author wrote the requirements for the selection of the averaging time for the interrupted noise method of measuring reverberation time in the international standard ISO 354:1985 "Acoustics-Measurement of sound absorption in a reverberation room". When this standard was
revised to become ISO 354:2003, the evaluation range used to measure the reverberation time was changed from 30 dB to 20 dB. Because the working group which revised the standard did not know the reasons for the averaging time requirements, they incorrectly changed them to supposedly take account
of the change to the evaluation range. The purpose of this paper is to give the reasons for the averaging time requirements so that they are corrected and not incorrectly changed again. It is necessary that the averaging time is not so large that information is discarded and so that, in the
case of exponential averaging devices, the measured decay rate is not biased by the decay rate of the exponential averaging device. On the other hand, it is desirable that the averaging time be as large as possible so that the ensemble standard deviation of the measured reverberation times
is as small as possible.
A robust force identification method based on L1+2-norm approximation theory
Authors: ZHANG Chao , MENG Hongli , WU Chengjun
Published: October 2024

Obtaining the real force of the structure is the basic condition for efficient vibration reduction design. However, the uneasiness and instability of the inverse problem make the force identification still challenging. On the basis of L2-norm regularization, we propose a new method
for force identification based on L1+2-norm approximation theory. By introducing the L1-norm penalty operator, a joint norm approximation optimization model is constructed to limit the non-zero force and punish the force value which approaching to zero, so that it can adapt to the identification
of various types of forces. Then the optimal force solution is obtained by using the Primal-dual interior point method. Finally, the effectiveness and accuracy of the proposed method are verified by numerical simulation and experiment of asymmetric plate and double-layer plate structures.
Different from previous studies, the L1+2-norm method in this work has high robustness, considers the characteristics of sparse regularization and L2-norm regularization, and can adapt to the identification of continuous forces and sparse forces at the same time, which has potential engineering
application value.
Inverse and direct impedance eduction of liners in the MAINE Flow facility
Authors: HUMBERT Thomas , RASHIDI Hamid , YANG Jinyue , GABARD Gwénaël , GOLLIARD Joachim
Published: October 2024

The assessment of acoustic liners typically involves conducting experiments with airflow in a duct under various incident sound pressure levels and flow velocities. Impedance, as the most intrinsic parameter characterizing an acoustic wall (due to its independence from the duct section),
is often the primary focus. Experimental techniques for its determination can be categorized into two classes: direct and inverse eduction methods. This paper contrasts these two methodological classes within the context of the MAINE Flow facility-a 150mm x 280mm rectangular duct capable of
generating flow Mach numbers up to 0.63 and multimodal sound fields of Sound Pressure Levels up to 150 dB. Direct impedance determination necessitates a substantial degree of attenuation along the liner. However, in the current implementation, inverse impedance determination is constrained
by the uniform flow hypothesis, which is invalid for large Mach numbers in such facilities. The findings illustrate that both methods can yield valuable impedance data, enabling the examination of the effects of flow and incident modal content on the measured impedance.
Laboratory measurement of the effect of exposure to ship noise on mussels
Authors: TORRES-GUIJARRO Soledad , ESTEVEZ-MARQUEZ Paula , BABARRO Jose MF , SILVA-CARIDE Elsa , SANTOS-DOMíNGUEZ David , COMEAU Luc A , GILCOTO Miguel
Published: October 2024

The mussel Mytilus galloprovincialis is a bivalve mollusc of high commercial interest, which frequently breeds in coastal areas with high levels of ship traffic noise. Studies on the effect of this stressor on mussels are scarce, which is why we set out to design a system to study the
effect of ship noise on mussel behaviour (valve opening-closure rhythms). The proposed experimental set-up uses a high frequency non-invasive valvometry system to detect shell closure reactions related to instantaneous increases in sound level. The main findings are that mussels reacted to
ship noise levels above 114 dB re 1μPa (63Hz-4kHz), that most reactions occurred within 13 s after a sudden increase in level, and that there does not appear to be a clear relationship between closure depth and noise level. Although mussels may not be sensitive to sound pressure but only
to the associated particle movement, the results of this work contribute to highlighting the sensitivity of this species to noise, and the need to carry out experiments with a larger number of specimens and in conditions that allow the acoustic field to be reproduced more realistically.
Results of a pilot study using experience sampling method to assess railway noise annoyance
Authors: ROUX Maël , LEMAITRE Guillaume , PHILIPPS-BERTIN Chrystèle , CHIELLO Olivier , AUMOND Pierre , LE BESCOND Valentin , CAN Arnaud
Published: October 2024

This article aims to report on the development of a method to study the acoustic factors driving the short-term annoyance experienced by neighbors of high-speed train lines (> 250 km/h). In fact, current indicators (e.g., LDEN) only partially explain annoyance caused by high-speed
trains noise. They could potentially be improved by considering some event-related aspects (e.g., the suddenness, spectral content, temporal fluctuations), whose role remains not fully understood. The development of a protocol dedicated to these issues is an essential prerequisite. A review
of the different methods used to study transportation noise annoyance highlights the benefits of the experience sampling method (ESM), not yet used for railway noise assessment. This method allows participants to report their annoyance right after a train pass-by with a remote device while
noise exposure is simultaneously recorded. We report on the results of a pilot study aiming to test an experimental protocol by proposing an adaptation of the experience sampling method to study annoyance caused by the passage of high-speed trains. Residents were recruited to take part in
the study and received two protocols in two different periods. The most efficient ESM parameters were determined, and further possibilities offered by this new methodology are discussed.
Effect of sound absorption on noise reduction in the automotive industry
Authors: YAMAN Muammer , KURTAY Cüneyt
Published: October 2024

Industrial noise is one of the most common physical factors that cause annoyance and damage workers' health in the long term. Precautions should be taken to reduce noise and improve acoustic performance in industrial working environments. This paper aims to analyze the acoustic performance
of the automotive industry and contribute to the global outcomes of sustainability and the development of strategies to improve the quality of the working environment through improvement scenarios. For this purpose, the automotive industry in Türkiye was examined as a case study. In-situ
acoustic measurements were made in the seat manufacturing unit of an automotive factory and the current situation was transferred to the simulation program. The effects of acoustic improvements on A-weighted sound pressure level and reverberation time at mid-frequencies (500, 1000, 2000 Hz)
were investigated through three different scenarios. In the investigations, noise distributions were carried out through noise mapping. The A-weighted sound pressure levels in the automotive industry were reduced by approximately 15 dB. As a result of the study, suggestions for noise control
precautions and their effects on the automotive industry seat manufacturing unit are presented.
Experimental validation of anomalous acoustic wave refraction using Double layered acoustic gratings
Authors: DU Liangfen , FAN Zheng
Published: October 2024

Acoustic metasurfaces (AMSs) have garnered increasing attention over the past decade due to their remarkable capability for wave manipulation. AMSs have been widely applied in diverse domains, including anomalous refraction and extraordinary sound absorption/isolation, among others.
However, typical AMS designs, such as Helmholtz resonator-like or labyrinthine structures, are often geometrically complex, limiting their practical usability. In this paper, we introduce an ultracompact Double Layered Acoustic Grating (DLAG) to achieve anomalous acoustic wave refraction.
The DLAG comprises double-layered rigid panels with multiple perforated subwavelength slits. By optimizing the positions of these slits on the rigid panels, the acoustic energy of an obliquely incident plane wave can be concentrated within a predetermined region in an arbitrary direction.
The paper will first review the theoretical background to predict the wave propagation controlled by DLAGs based on the surface coupling approach. Subsequently, the underlying principle to achieve anomalous refraction using DLAGs will be discussed. A 3D-printed DLAG with the optimized slit
positions is used for demonstration. In the experiment, the acoustic energy of a plane wave with an incident angle of 36 degrees was successfully collimated within a predetermined focusing region with a negative refracted angle of -36 degrees.
Design and evaluation of an acoustic liner applied to a UAV ducted rotor in hover
Authors: SIMON Frank
Published: October 2024

Unmanned aerial vehicles (UAVs) are currently being used for reconnaissance missions, tactical surveillance, and infrastructure inspection. These missions and operations could be performed near inhabited areas, possibly leading to noise complaints. For most UAVs, the rotor blades are
the dominant source of noise. While some UAV concepts are equipped with rotor ducts for aerodynamic and safety reasons, few studies focus on the acoustic benefit of rotor ducts with integrated acoustic liners, similar to implementations on turbofan aircraft. The liner concept used in this
study, called a Long Elastic Open Neck Acoustic Resonator (LEONAR), achieves good low frequency performance in a limited available space. The LEONAR concept extends the holes of the facesheet perforations into the resonator cavities with hollow tubes. As a result, the columns of air in the
facesheet holes are prolongated without increasing facesheet thickness, thereby shifting the resonant frequencies of the liner lower. The objectives of this paper are to describe the simulation of noise radiated from a rotor in a duct with a LEONAR liner, the design of a liner integrated along
the duct inner surface to mitigate radiated noise between 1000-5000 Hz, and impedance tube tests of liner samples to validate the predicted impedances.
Development and distribution of an in situ experimental wind turbine noise database
Authors: GUILLAUME Gwenaël , COTTé Benjamin , ECOTIèRE David , GAUVREAU Benoit , LEFèVRE Hubert , JUNKER Fabrice , SCHMICH-YAMANE Isabelle
Published: October 2024

The PIBE project is the first French collaborative research project on wind turbine noise. One of its objectives is to quantify the experimental dispersion observed in situ on acoustic quantities/metrics and influencing parameters, and to compare it with the numerical dispersion estimated
using acoustic propagation models. A long-term experimental campaign was carried out over consecutive 410 days around a wind farm comprising eight 80-metre-high and 90-metre diameter turbines. Acoustic sensors (five Class I sound level meters) were deployed on site, recording third-octave
spectra and overall A- and Z-weighted values of the Leq indicator and fractile indices (L10, L50 and L90), at distances from 325 m to 1400 m from the wind turbines row. In addition, three 3D ultrasonic anemometers and a Lidar system were used to measure meteorological variables influencing
long-range sound propagation (e.g. wind and temperature verical profiles). Besides, train and aircraft passing close to the site were inventoried to identify periods of high background noise. All experimental data have been processed into an ElasticSearch database. An interactive web application
has been developed in R Shiny to facilitate processing, visualization and analysis of the experimental database.
Acoustic characterization of the Municipal Museum Abade Pedrosa
Authors: GOMES BARBOSA Sofia , CARVALHO António , COSTA António E.
Published: October 2024

The 2016 interventions concerning the rehabilitation of the Municipal Museum Abade Pedrosa in Santo Tirso, Portugal were analyzed to verify in what way acoustics interferes in the museum enjoyment. In situ measurements were done in every exhibition room: Reverberation Time, RASTI and
the Equivalent Sound Level (LAeq). RT[500, 1k, 2k Hz] values were between 2.5 and 3.9 s. The RASTI mean values varied between 0.44 and 0.55 s. LAeq values of background noise reached a top value of 43 dB(A) in the 1000 Hz frequency band and a global value of 57 dB(A) in every room. A multicriteria
analysis was carried out to globally characterize the museum in a simple and perceptive way, with an algorithm that ranks all the different rooms, in which they were generally classified as "bad". A comparison of these values was done with similar studies in other museums: Soares
dos Reis (Porto), Serralves (Porto) and other international museums, being possible to verify that the Municipal Museum Abade Pedrosa has worse acoustic values compared to those other museums. It was also suggested possible improvements that could contribute for the acoustic correction of
the space, with a predictable cost of about 27000 €.
Swiss railway field laboratory: analysis of two years' data collection
Authors: SCHMID Marc , ZUMBRUNNEN Niki
Published: October 2024

Since May 2022, a 1 km long section of the regular train network of Switzerland between Lucerne and Olten has been equipped with a variety of sensors and microphones. The superstructure of this test track was renewed in December 2019 and consists of ballasted track with concrete sleepers,
in part with and without stiff under sleeper pads, respectively. Since June 2022 the sensors and microphones have continuously recorded pass-by data for sound, vibration and track dynamics for every passing train. This long-term measurement installation allows studying different environmental
influences on noise and vibration. The very large amount of data enables both statistical analysis and building statistical models. Furthermore, the railway field lab can be used determine the influence of different track components. In this paper, we report on our statistical analysis of
the data gathered since June 2022 including statistical models of the influence of the environment and of different rolling stock on sound and vibration. Furthermore, we present the results of a novel high damping rail pad tested at the railway field lab. Based on these results, we present
a proposal and discuss our thoughts on the best practice for measuring acoustic quantities.
The contribution of dynamic cues to externalization of virtual source in virtual auditory display
Authors: LIU Ding , XIE Bosun , ZHU Jun , DU Shanwen
Published: October 2024

It is well known that static virtual auditory display with headphone is inclined to create the auditory perception of in-head-localization, especially for target virtual sources in the median plane. By introducing the dynamic variation of binaural pressures caused by head turning, dynamic
virtual auditory display eliminates the in-head-localization effectively. The present work investigates the contributions of dynamic interaural time difference (ITD) and dynamic interaural level difference (ILD) in binaural pressures to the externalization of auditory perception. By modifying
the head-related transfer functions used in a dynamic virtual auditory display, binaural signals with dynamic ITD or dynamic ILD alone are created and presented by headphone. A psychoacoustic experiment is conducted to evaluate the extent of perceived externalization. The experiment results
prove that, for the target virtual source in the median plane, dynamic ITD and dynamic ILD contribute to the externalization of low and high frequency components of the stimuli respectively. For wideband stimulus with low and high frequency components, both dynamic ITD and dynamic ILD contribute
externalization but dynamic ITD contributes more than that of dynamic ILD.
Physiological responses to soundscape recordings in a laboratory experiment
Authors: LAUFS Christian , RAY Alokeparna , HERWEG Andreas
Published: October 2024

The evaluation of acoustic environments using the soundscape approach offers the possibility of a holistic analysis. Physiological measurements can complement this approach in order to provide continuous information on the listener's physiological response to the acoustic environment
and also record unconscious responses. However, it is essential to clarify which differences in the soundscape characteristics can induce significant changes in the physiological response of the listener. In addition to physiological measurements, listening tests in virtual reality can complement
the approach to include soundscape context in laboratory studies to a greater extent. The study conducted in this paper therefore represents a preliminary study for experiments in virtual reality and investigates the reaction of the participants' skin conductance to various soundscape recordings
in a laboratory setting. The analysis of the physiological data reveals aspects of soundscapes that are more likely to elicit a stress response or relaxation and shows how much soundscape recordings need to differentiate from each other such that physiological measurements can add value to
the holistic soundscape approach.
Railway-induced vibration combined with railway noise - a systematic review with exposure-effect curves
Authors: SEIDLER Andreas , SCHUBERT Melanie , MEHRJERDIAN Yasmin , KRAPF Klaus , POPP Christian , VAN KAMP Irene , ÖGREN Mikael , HEGEWALD Janice
Published: October 2024

The combined health impact of concurrent railway noise and railway vibration exposure is not yet well understood. This systematic review aimed to investigate the combined effects of vibration and concurrent noise. We converted the vibration metric to an equivalent noise level and calculated
an overall noise level by energetically summing the equivalent and railway noise level. The combined health effect was determined by using published evidence-based exposure-effect formulas. Studies included in this systematic review predominately investigated annoyance and self-reported sleep
disturbances; no studies on manifest diseases were identified. For the combined effects of vibration and noise on "total" annoyance, the results based on the pooled analysis of CargoVibes project are recommended as conservative approach. Our results based on epidemiological studies
are corroborated by findings of laboratory studies. Converting railway vibration into equivalent noise levels in dB may offer a pragmatic approach to assess the combined health effects of railway noise and railway vibration exposure. Future studies should include cardiovascular and mental
diseases in addition to vibration-induced annoyance and sleep disturbances. Furthermore, future studies should include in-depth investigations of the interaction between railway noise and railway vibration to allow for a more accurate assessment of the railway-induced burden of disease.
The Influence of bogie cavity bottom plate on the aerodynamic noise characteristics of high speed trains
Authors: LIRONG JIA , SHUANBAO YAO , DAWEI CHEN , JIALI LIU , SANSAN DING , YE ZHANG
Published: October 2024

The bogie area with a complex structure is an extremely important source of noise for trains. Based on the large-eddy simulation(LES) and Ffowcs Williams-Hawkings(FW-H) analogy, aero-acoustic simulation was conducted on a 3-car high-speed train of a certain type with a bogie cavity
bottom plate installed on the front and rear cars. The results show that bottom plate changes the flow field around the bogie, weakens the flow separation of airflow at the leading edge of the bogie cavity, mitigates the flow impact of airflow on various components of the bogie, suppresses
the formation and detachment of large-scale vortices in the bogie area, and reduces the formation of pressure pulsations on the geometric surface of the bogie area. The bogie cavity bottom plate scheme reduces the far-field aerodynamic noise of the train by 1.63dBA, and the noise reduction
effect is significant. The aerodynamic noise of the measurement point equipped with a bogie cavity bottom plate is lower than that of the conventional bogie cavity in all frequency bands, and the energy reduction is more significant at medium and low frequencies.
Mid-frequency propagation path analysis on vehicle body using structural intensity
Authors: UEHATA Shogo , ARAI Katsuhiko
Published: October 2024

With the penetration of electric vehicles, reduction of structure-borne road noise gets important issue to realize comfortable vehicles for customers.Sound generation mechanism of structure-borne road noise on vehicle body is analyzed basically by modal analysis in low-frequency range.
On the other hand, as frequency increases, modal analysis cannot clarify vibration mechanism because vibration wavelength gets shorter, mode density gets high and mode shape gets complicated. Therefore, it is difficult to identify efficient countermeasure parts and inefficient damping materials
are added to response panels in mid-frequency range. So alternative analytical methods in mid-frequency range are under research to understand vibration mechanism. In this paper, Structural intensity (SI) analysis is introduced to clarify sound propagation mechanism. This analysis method makes
it possible to clarify the main energy propagation path from input point to vibrating panels on vehicle body. The results show that SI analysis unveils the main energy propagation path and gives the opportunity to reduce the panel vibration efficiently by controlling the energy propagation
path in body frame structure without damping materials.
Experimental analysis of eigenmode frequency of an hydrofoil on trailing edge hydroelastic coupling generating tonal noise
Authors: FRANCOIS Paul
Published: October 2024

The majority of anthropogenic noise in the oceans is due to commercial, military or tourist motorized navigation. Lifting surfaces such as hydrofoils, propeller blades, rudders and stabilizers can be prone to flow induceed vibrations and, under certain conditions, to produce tonal noise.
Reducing vibration and noise generated by this type of structures, is therefore an important issue to limit noise pollution and to improve the acoustic discretion of ships. This study, carried out at the French Naval Academy Research Institute, highlights the hydroelastic coupling mechanism
responsible of trailing edge vibrations and of lifting surface tonal noise evolving in laminar to turbulent transition regime. This experimental research was carried out in a hydrodynamic tunnel with a NACA0015 hydrofoil, for angles of incidence ranging from 0° to 12° and Reynolds
numbers varying from 200,000 to 1,200,000. Laser vibrometry was used to specify the vibrational behavior of two identical hydrofoil made of aluminum and brass in order to estimate the influence of material and eigenfrequency on tonal noise generation. The results show that, contrary to the
same mechanism in air, tonal noise of hydrofoil was strongly dependent of the natural frequency of the profile.
Multimodal Hong Kong: a multisensory study of environmental perception of places through sight, sound, and smell
Authors: JIANG Qianxi , LINDBORG PerMagnus , WEI Lishan , XIAO Jieling , YUE Ran
Published: October 2024

Despite the importance of soundscape and smellscape in intangible cultural heritage, little is known about multisensory interactions. To explore the impact of multiple senses on environmental perception, the present study focused on six stalls at Shek Kip Mei wet market in Hong Kong.
In the first part of the study, an online survey collected perceptual ratings of whole, auditory, and visual environmental quality, as well as free-form responses of imaginations of smell. Participants (N = 36) were presented with 12 audiovisual captures where audio was either matched with
video or mismatched. ANOVA was used to examine the influence of three independent factors - scenes, modes, and a priori valence groups - on the ratings. The imagined smells were analysed through frequency counts of keywords. The results demonstrate participants' capacity to notice changes
in audio modes and to perceive the environment through the recognition of scene context and multisensory interactions. In the second part of the study, not discussed in the present paper, we will extend this experimental method to include smells in a laboratory setting. We discuss the importance
of understanding multisensory interactions between sight, sound, and smell for environmental perceptions and Hong Kong's intangible cultural heritage and urban studies.
Numerical investigation of simply supported periodic rectangular plates with acoustic black hole wedge
Authors: BAO Yue , LIU Xiandong , YU Yongning
Published: October 2024

In this paper, we propose the periodic rectangle plate with one-dimensional acoustic black hole (ABH) wedge under the simply supported condition. The vibration performances have been investigated by the semi-analytic method based on the levy solution method combined with WKB approximation,
which is also validated by finite element method (FEM) simulation. For the rectangle ABH wedge, we derive the flexural wave dispersive relationship in plate, which also revealed the cut-on frequency. It can also be found that with the increase of periodic number, the vibration of plate structure
can be reduced not only in the high frequency range where traditional ABH effect takes effect, but in low and middle frequency range the periodic ABH wedge can also show its advantage. Meanwhile, the damping coupling performance between the periodic ABH wedge and attached damping layers has
also been investigated to enhance the vibration reduction. This novel kind ABH structure shows its potential in engineering applications.
Infrasound sensing: toward new measurement methods and controlled sources
Authors: GARCIA Raphael , LORIDANT Polo , BERNAUER Félix , PILZ Marco , SOURNAC Anthony , WILHELM Arnaud , MIMOUN David
Published: October 2024

The infrasound waves have already demonstrated their potential to characterize natural and man-made sources and to image the structure of atmosphere. These scientific acheivements have been driven mainly infrasound sensing by pressure sensor arrays deployed on the ground, with a strong
contribution by permanent arrays developed in the framework of CTBT. However new infrasound sensing methods have been developed during the past two decades with very different concepts that allow to sense these waves at different altitudes in the atmosphere. We will recall a few key results
associated with these new sensing methods on satellite and balloon platforms, as well as the ones using ionospheric perturbations. Concerning the infrasound sensing at ground level, we will explain how the infrasound waves can be monitored through ground movements and illustrate this method
by the detection of infrasonic waves on Mars by SEIS seismometer of InSight NASA mission. Advantages and drawbacks of infrasound monitoring through ground movements will be presented, in particular the sensitivity to wind. Preliminary results comparing different infrasound sensing methods
on the Earth will be presented. Eventually, we will also discuss shortly controlled infrasound sources and illustrate this discussion with recent experiments using burners as an infrasound source.
Experimental and numerical investigation of soundproof panels using acoustic metamaterials with porous material
Authors: ARITA Shoko , TOMITA Sunao , NAKANO Sachito , SHIMANUKI Kento , UMEMOTO Kazuhiko
Published: October 2024

Acoustic panels are often used in buildings and automobiles. For sound absorption in panels, high sound absorption performance in a wide frequency band can be achieved by combining porous sound absorption, resonant sound absorption, vibration sound absorption, and acoustic metamaterials.
This study proposes a highly sound-absorbing panel structure by using an acoustic metamaterial that generates local resonance to a double-walled structure filled with porous material. In the soundproof panel of this study, local resonance is generated by a structure in which slits are made
in a porous material. By the through-holes of the slits, local resonance occurs, but sound leakage and thermal viscosity in the slits may affect the sound absorption effect. Therefore, in this study, sound transmission loss for various cases with differing factors such as the use of porous
materials, the presence of spiral slits, and layer configurations are compared through the acoustic analysis and experiments. The results substantiate that the proposed panel structure has high soundproofing performance in wide frequency ranges, each driven by distinct physical principles.
The use of ensembles trees machine learning method in estimating damping of granular materials
Authors: BADRI Yousif , HALL Andrew , DODD George , CATER John , SCHMID Gian , EMMS Grant , CALIUS Emilio
Published: October 2024

Granular Materials (GM) employed within the mechanism of particle dampers attenuate the vibration energy due to their interparticle and particle-wall interactions. Estimating their damping effect using the analytical equivalent single mass approach overlooked the particles' individual
losses that are built into the total damping. Alternatively, the numerical techniques (e.g., Discrete Element) are time-inefficient and computationally demanding. Therefore, this study explores the implementation of Machine learning (ML) algorithms to estimate the damping effect of GM. The
ML model in this study will rely on a Data-Driven Modeling approach (DDM) incorporating the ensemble tress nonlinear regressor method. The models' training and testing data were obtained from an experimental setup of an acrylic beam internally integrated with Stainless Steel (SS) and glass
spheres undergoing low excitation amplitude (RMS <1N). The main aim was to map between seven input features (e.g. filling ratio) and one targeted output: the beam's damped frequency response. Three ensemble trees' algorithms were used to create the DDM; Decision Tree, Random Forest, and
XGBoost. The hyperparameter combination based on the Gridsearch CV function increases the prediction accuracy of each model. The developed ML models provided high accuracy (86-93%) in predicting the damping effect of the granular materials spheres.
Comparison of active and passive vibration control techniques for electric drive power electronic subsystem: Experimental validation
Authors: PRASAD Braj Bhushan , LUFT Tommy , MICHAELSEN Christopher , ROTTENGRUBER Hermann
Published: October 2024

Reducing vibration and noise from power electronics components is vital for enhancing the performance and acceptance of electric vehicles, emphasizing the need for effective mitigation strategies in sustainable transportation. This paper compares passive and active vibration techniques,
with a specific focus on utilizing particle damping for passive vibration control. The method achieves vibration reduction through viscoelastic deformation and friction resulting from the movement and collisions of granular material within the cavity. This contribution outlines diverse design
strategies for integrating particle dampers into power electronic components. The active control approach, operating typically in the 50 Hz to 1200 Hz frequency range, can concurrently support passive noise treatments. Piezoelectric ceramics serve as both actuators and sensors in active noise
reduction. Following the identification of dominant mode shapes, appropriate actuator and sensor positions are chosen. The control problem of the smart system is then addressed, opting for a velocity feedback control algorithm in a real collocated design. This algorithm computes input signals
for actuators bonded to the outer surface, achieving significant active damping effects. Lab-tested techniques are validated in real-world conditions with a full-scale electric-drive toolkit, affirming their efficacy in reducing vibration and noise and underscoring their potential for implementation
in electric vehicles.
Feedback on the creation of a scientific show using immersive sound
Authors: GAZENGEL Bruno , AYRAULT Christophe , PAQUIER Mathieu , DAMIEN Arnault
Published: October 2024

This presentation is devoted to feedback on the creation of a scientific show produced in collaboration between two acoustic laboratories, musicians and a loudspeaker manufacturer. The aim of the show is to simply explain sound perception to a wide audience using an immersive sound
system. The presentation focuses on the creative process (including scenario writing, musical compositions, choice of technical solutions for the audio rendering) and the compromises made between scientific rigor and the artistic aspect. The various phases of the work carried out over almost
two years are explained in order to formalize the creative process and the need to find a specific method that is suitable for both artists and scientists.
Computation-efficient virtual sensing approach with multichannel adjoint least mean square algorithm
Authors: WANG Boxiang , JI Junwei , SHEN Xiaoyi , SHI Dongyuan , GAN Woon-Seng
Published: October 2024

Multichannel active noise control (ANC) systems are designed to create a large zone of quietness (ZoQ) around the error microphones, however, the placement of these microphones often presents challenges due to physical limitations. Virtual sensing technique that effectively suppresses
the noise far from the physical error microphones is one of the most promising solutions. Nevertheless, the conventional multichannel virtual sensing ANC (MVANC) system based on the multichannel filtered reference least mean square (MCFxLMS) algorithm often suffers from high computational
complexity. This paper proposes a feedforward MVANC system that incorporates the multichannel adjoint least mean square (MCALMS) algorithm to overcome these limitations effectively. Computational analysis demonstrates the improvement of computational efficiency and numerical simulations exhibit
comparable noise reduction performance at virtual locations compared to the conventional MCFxLMS algorithm. Additionally, the effects of varied tuning noises on system performance are also investigated, providing insightful findings on optimizing MVANC systems.
A dynamic stiffness method to estimate the sound insulation of an arbitrarily installed thick cross laminated timber (CLT) plate
Authors: CHURCHILL Claire , MEGGITT Joshua , WONG MCSWEENEY Daniel , COX Trevor , FILIPPOUPOLITIS Marios , WOODCOCK James
Published: October 2024

There is no generally accepted standard methodology to determine the dynamic constants of whole cross laminated timber (CLT) plates. Combined with the observation that CLT walls or floors are installed in situ under very different conditions to laboratory measurement conditions a methodology
is sought to determine the sound insulation of CLT plates installed under arbitrary conditions without accurate information concerning the dynamic constants (and boundary conditions). The methodology may have applications where a panel can be tested in situ e.g. in pre-completion testing.
In the laboratory measurement a CLT plate was mounted on the laboratory floor on two wooden joists placed at arbitrary positions to support the weight of the plate to represent a possible installation in situ.
Few-shot bioacoustic event detection utilizing spectro-temporal receptive field
Authors: MIN DEOKKI , NAM HYEONUK , PARK YONG-HWA
Published: October 2024

Bioacoustic event detection is a task of identifying specific animal sounds within a biological audio recordings. Specialists only can label temporal information of animal sounds since knowledge for biological sound is demanded for labeling and they can give only few annotations due
to high labor intensity caused by large duration of biological recordings. Therefore, the task is set to few-shot learning scheme and method called prototypical network effectively deal with the few-shot learning scheme by learning representation space which represent each class for given
few examples. In this work, we utilized spectro-temporal receptive field, which is inspired auditory cortex which responses actively to certain spectro-temporal modulation, as a convolutional layer kernel of prototypical network. Bioacoustic events retain plentiful spectro-temporal modulation
that STRF is expected to capture animal sounds effectively. Also, STRF kernels are constructed to fixed shape rather than trained that a model utilizing STRF kernels would learn representation space with less parameter. We built a model called Two Branch STRFNet (TB-STRFNet), in which STRF
branch captures spectro-temporal modulation by STRF kernels and the other branch captures detailed time-frequency information which can be smashed in STRF branch. TB-STRFNet outperformed other models showing that effectiveness of auditory system inspired method.
Evaluating the relationship between high-frequency hearing loss and front-back localization in the elderly
Authors: WANG Xiaoman , QINGLIN MENG , ZHIYUAN LIN , JIN YU , YEWEI WANG , ZHELIN LI , BOSUN XIE
Published: October 2024

Sound localization is an essential ability for normal hearing listeners, aiding in the localization of objects and the detection of potential dangers, as well as enabling the extraction of target speech information in a noisy environment. However, high-frequency hearing loss, commonly
observed in the elderly population, may lead to a decline in spatial localization ability. The present work evaluated the ability of horizontal localization of 60 elderly individuals in a psychoacoustic experiment and investigated the relationship between localization impairment and hearing
loss in different frequency ranges. Results indicate that high-frequency hearing loss above 2 kHz has a minor impact on left-right localization, but significantly impairs front-back localization. The physical and psychoacoustic explanations are provided for the experimental observations.
NCPAProp: an open-source, modular infrasound propagation modeling package
Authors: HETZER Claus , WAXLER Roger , ASSINK Jelle , VELEA Doru
Published: October 2024

NCPAProp is a command-line-driven, fully open-source software package first released in 2016 and under continuous development since then. It aims to provide a comprehensive set of tested and validated full-wave numerical models to simulate long-range propagation of infrasound through
realistic atmospheres, at frequencies nominally in the range of 0.1-10 Hz. The package currently includes two normal-mode models of varying complexity, and a parabolic equation model with the option to include a range-dependent atmosphere and orography. This presentation will focus on a description
of the models, a discussion of their use, and a summary of the short-term and long-term ongoing development goals for the overall package.
Trainable signal encoders that are robust against noise
Authors: BALAZS Peter , HAIDER Daniel , LOSTANLEN Vincent , PERFLER Felix
Published: October 2024

Within the deep learning paradigm, finite impulse response (FIR) filters are often used to encode audio signals, yielding flexible and adaptive feature representations. We show that a stabilization of FIR filterbanks with fixed filter lengths (convolutional layers with 1-D filters)
by means of their condition number leads to encoders that are optimally robust against noise and can be inverted with perfect reconstruction by their transposes. To maintain their flexibility as regular neural network layers we implement the stabilization via a computationally efficient regularizing
term in the objective function of the learning problem. In this way, the encoder keeps its expressive power and is optimally stable and noise-robust throughout the whole learning procedure. We show in a denoising task where noise is additionally present in the encoder representation of the
signals, that the proposed stabilization of the trainable filterbank encodings is decisive for increasing the signal-to-noise ratio of the denoised signals significantly compared to a model with a naively trained encoder.
Design and analysis of Conceptual acoustic metamaterials applied to mitigating cooling fan noise for heavy-duty vehicles
Authors: NA Wei , JI Chenya , REDDY Prajwal Sunil , KEULEMANS WESTLIN Christina , LUVö Sofia , YAO Hua-Dong
Published: October 2024

The noise generated from cooling fans in heavy-duty vehicles like trucks poses challenges regarding environmental pollution and overall user comfort. To solve this problem, this study develops an acoustic metamaterial (AMM) that is constructed with small Helmholtz resonators in two
layers. This concept can attenuate the noise in a broad frequency range. Furthermore, the particle swarm optimization (PSO) algorithm based on artificial intelligence (AI) is used to optimize the AMM structure. The key design parameters are discussed and analyzed. The installation strategies
are put forth to examine the performance of the AMM. The proposed metamaterials, combined with the installation strategies, are numerically simulated using the finite element method. The results show that the current AMM is effective in reducing both tonal and broadband noise of interest.
The findings shed light on the development of acoustic metamaterials for cooling-fan noise reduction in heavy-duty vehicles.
Noise in a UK intensive care unit: a retrospective cohort study
Authors: HAMPTON Thomas , WAITE Alicia , TAHVILI Ava
Published: October 2024

Excessive noise in hospital Intensive care units (ICU) has been associated with adverse health effects and human factor impacts acknowledged to negatively affect both patients and healthcare providers. Aims: Evaluation of the acoustic environment of the Royal Liverpool University Hospital
(RLUH) ICU versus WHO and UK guidelines. Methods: Noise measurements were taken from a six-bedded bay within the RLUH ICU between 15th June and 1st July 2022. This audit focussed on noise data > 87dBA, in accordance with the national exposure limit established by UK Noise Regulations. A
retrospective review of relevant patients' records was conducted to identify potential noisy events during the audit period. Results: The highest and lowest LAeq value was 77.9 and 63.5dBA, respectively. All LAeq and LAmax noise measurements recorded exceeded recommended guidelines. Noise
fell below recommended daytime guidelines less than 1% of the time. The top potential causes of noise were patient repositioning/personal care, medication administration and suctioning. Conclusion: Noise levels in the RLUH ICU considerably exceed national and international guidelines. These
findings highlight the need to address noise pollution in the ICU setting. Hospital staff and policy makers should consider implementing strategies and interventions for noise reduction in ICUs.
Directional excitation of structural vibrations due to correlated sources
Authors: TANNER Gregor , FINN Joshua , RICHTER Martin , AIMAKOV Nurkanat
Published: October 2024

Dynamical Energy Analysis (DEA) is an approach used to compute the vibro-acoustic response of complex structures to externally applied high-frequency excitation. DEA tracks the global energy flow in a structure in terms of a local ray tracing approach implemented on meshes. Due to its
in-built directional set-up, the approach is ideally suited for modelling the response of structures to directional excitation. Examples thereof are dipole sources or - more generally - correlated and distributed source excitation such as due to a Turbulent Boundary Layer (TBL) excitation
across an aircraft wing during flight. We will demonstrate here how such directional sources are implemented in a DEA setting. TBL induced sources or general correlated sources can be described in terms of appropriate force or wave correlation functions (CF). Using Wigner-transformation, these
CFs can be associated with a directional energy flow source. Vibrational energy field results are presented for a pair of phase-locked point forces. Results are also presented for 9 point-sources, which demonstrate the ability to channel the energy flow away from the sources by carefully choosing
their relative phases. An implementation of this approach within DEA is also presented, with results demonstrating strong agreement with direct calculations.