bluuebunny/crossref_metadata_2025 huggingface dataset:
An open-source time-domain wave-based room acoustic software in Python based on the nodal discontinuous Galerkin method
Authors: WANG Huiqing , PALHA Artur , HORNIKX Maarten
Published: October 2024

In this work, we introduce an open-source implementation of a time-domain wave-based room acoustic modeling software package, named DG_RoomAcoustics. In this software, the linear acoustic equations are spatially discretized by the nodal discontinuous Galerkin method, and are integrated
in time by either the explicit Runge-Kutta or the arbitrary high-order derivatives (ADER) integration schemes. Following the principles of object-oriented programming paradigm, the software is structured to ensure generic applicability and to facilitate future extensions with additional functionalities
(e.g., different time integration schemes, boundary conditions). A comprehensive presentation of the physical and numerical aspects of the problem is provided. A detailed exposition of the code structure and components is presented, all of which are released under an open-source license, fostering
community feedback and collaborative contributions for ongoing improvements. A brief overview of the current capabilities of the software is introduced. Future work regarding possible functionality extensions and performance optimizing are discussed.
Effect of reverberation chamber volume on result of qualification procedure for loudspeaker and loudspeaker positions for airborne sound insulation measurements
Authors: BARTNIK Wojciech , CHMIELEWSKI Bartosz
Published: October 2024

Measurement of sound insulation from airborne sound is carried out by determining the level of sound power radiated by the test item. In laboratory practice, this translates into measuring the sound level in the transmitting and receiving chambers and measuring the reverberation time
in the receiving chamber. When performing these measurements, significant fluctuations in the sound level for low frequencies can be observed, which is related to the occurrence of standing waves inside the chambers. To ensure proper level averaging, as well as repeatability and reproducibility
of measurements ISO 10140-5 describes a qualification procedure for sources and source positions. This article presents the effect of increasing the volume of the source chamber on the results of the qualification procedure for sources and source positions for floor airborne sound insulation
measurements.
Influence of the fundamental frequency and number of harmonics on preference judgements for fan sounds
Authors: CLAAßEN Eike , TöPKEN Stephan , VAN DE PAR Steven
Published: October 2024

Fan sounds are often heard in everyday life. Besides broadband noise, the sounds often contain one single or multiple tonal components, which can render the sound rather unpleasant and annoying. In this study, level adjustments for equal preference were measured in listening experiments
for synthetic fan sounds compared to a fixed reference sound. The stimuli were based on two different background noises with one embedded single tone, or a multitone with eight partials. The tonal components had fundamental frequencies of either 80 or 240 Hz. All sounds containing tones needed
level reduction to become equally preferred as the reference sound. The tonal configuration, as well as its fundamental frequency, did typically influence the effect. Additional level reductions for signals containing higher harmonics were necessary to reach equal preference compared to signals
that contained only a single tone. For a fundamental frequency of 80 Hz, the additional level reductions were only 1.5 dB on average, for a fundamental frequency of 240 Hz up to 9.7 dB were necessary. The level reductions for equal preference were larger for sounds using a background averaged
across real fan sounds compared to using bandlimited synthetic noise.
Industrial plant noise mitigation starting from the plant first runs
Authors: RIZZI Lorenzo , COLOMBO Mauro , COLOMBO Fabrizio , NASTASI Francesco
Published: October 2024

The article summarizes a noise impact mitigation study that was carried out in the Liguria region in Northern Italy, between July 2020 and March 2022 on a large industrial plant that produces zinc oxide. The authors were summoned at the plant first run tests, so this study started without
a participation in the industry planning and design phases. We followed the main machine installations and perfected the mitigation project accordingly: priorities were updated after each assessment and new modelization. This approach was carried out with different SPL measurement campaigns
and the use of sound-intensimetry and a beam-forming SEVENBEL antenna. A SoundPLAN 3d model was updated step by step, defining a designing ad hoc noise control strategies and solutions, in order to respect the Italian administrative noise regulations. The mitigation works were directed by
one of the authors and included different approaches: such as some large cylindrical silencers on the smoke stacks, sound barriers and insulating coatings, as well as fan velocity optimization.
Numerical study of the vibration control performance of Kelvin foam
Authors: CAI Zenong , HENRIQUEZ Vicente Cutanda , LUCKLUM Frieder
Published: October 2024

Vibration control in microsystems is an important challenge. Because of the space limitation, structures that consume minimal space but provide effective performance need to be identified. In this research, we evaluate the vibration damping performance of various Kelvin-cell structures
in microsystems using the Finite Element Method. Nine types of unit cells are designed based on the tetrakaidecahedron with different geometric parameters. The lattices are composed of the aforementioned unit cells, and two types of boundary condition are set according to the actual application
scenarios. The results of the simulation include dissipated energy , isolation efficiency, etc. The results are compared with each other and two types of non-Kelvin-cell structures. This comparative analysis aims to inform the development of space-efficient vibration absorbers for microsystems.
Estimation of bridge noise during the passage of trains with worn wheel treads from rail vibration in a different section
Authors: SUEKI Takeshi , SEKINE Kenji
Published: October 2024

Bridge noise may increase when a train with worn wheel treads passes. This study attempted to estimate bridge noise when a train with worn wheels passed based on rail vibration in a different section, i.e., using accelerometers on the rail near a station and a vehicle maintenance depot.
The rail vibration in a different section was converted into that in a section where bridge noise was required to be estimated. In the estimation, the vibration properties of the wheel, track, and contact spring in both sections were considered, and it was assumed that wheel roughness exceeded
rail roughness at spatial frequencies where the influence of the wear was observed. The bridge noise generated by one wheel was estimated from the bridge vibration and converted from the rail vibration with transfer functions by considering the radiation area of the viaduct. The overall bridge
noise was obtained by summing the noise generated by all the wheels in a train. The estimated results were consistent with the measured values at frequencies where the wear had a strong influence.
Blocked force characterization and transposition at secondary connections of a compressor
Authors: GARDIN Thomas , GRAS Thibaut , MACQUART Alexandre , ZERGOUNE Zakaria , IKEN Mohamed , LABED Malek
Published: October 2024

Applications in sustainable energy systems, like heat pumps, are encountering emerging challenges, among which acoustic comfort stands out as a critical factor in shaping the end-user experience. Early integration of vibroacoustic into each industrial design phase ensures the prevention
and prediction of potential noise issues, thus avoid costly design modification loops. BDR Thermea and CETIM, in a collaborative project, have implemented new methodologies for designing acoustically optimized products, highlighting the importance of considering vibroacoustic design at each
design stage of new products developments. In this study, structure-borne noise characterization methods are applied to a heat pump compressor using the ISO 21955 and ISO 20270 standards. The forces transmitted at its suction and discharge ports were studied through component based TPA for
the intrinsic characterization of the compressor. Once obtained, these forces were transposed to a new receiving structure. The results allowed a comparison of the outcomes from both approaches and highlighted the importance of considering the influence of the stiffness of the connections
at the compressor ports.
A method for studying the effect of diegetic vs. non-diegetic rating interfaces on the assessment of virtual acoustic environments
Authors: MEIER Niklas , FONTAINE Konstantin , FIEBIG André
Published: October 2024

Auditory perception experiments conducted in VR come along with a high degree of ecological validity while maintaining a controlled laboratory setting. However, since the participant's vision is occupied during simulation, conventional evaluation instruments like rating scales need
to be relocated to the virtual environment to allow for immediate stimulus rating. This can be achieved either by the use of diegetic interfaces, which are implied to be a part of the simulation (e.g., a screen held by the participant's avatar) or non-diegetic interfaces, which do not claim
to originate from the simulated reality (e.g., sliders and text elements laid on top of the participant's view). It is unknown whether the choice of interface does affect the participant's perception of the virtual environment - including its acoustic components. To address this shortcoming,
a methodological study is presented. Participants are exposed to a virtual scenario simulating an urban green area with nearby ambience sound sources. In this setting, they are provided with diegetic and non-diegetic rating interfaces to assess the acoustic environment. Subsequently, perceived
presence and involvement in the virtual environment are surveyed as well. This way, the study provides useful guidelines for future VR experiments assessing soundscape-related aspects of perception.
Experimental study on sound propagation caused by disturbance of wake flow on water surface boat
Authors: GUO Kaihui , ZHAO Kaiqi , WU Yan , FAN Jun , WANG Bin
Published: October 2024

The research on underwater sound propagation generally assumes that the water is static. However, when a boat passes on the water surface, its wake can cause disturbance to the stable sound field. The main reason is that the wake changes the temperature and salinity distributions of
seawater in the just field, thereby affecting propagation loss. This article conducts a time-frequency analysis of the sound signal propagated by the boat wake. Results show that the wake not only affects the propagation loss but also causes obvious fluctuations in the envelope of the received
signal. This fluctuation indicates the frequency modulation of sound by the boat wake. These changes in sound propagation are not only related to the boat speed but also to the signal frequency.
Construction site noise management
Authors: ACQUATI MARCO , XHIXHA ELONA
Published: October 2024

In recent years, the number of noise nuisance complaints has increased dramatically. Prominent among these are complaints about noise nuisance from construction sites. Most construction sites are the source of high, repetitive and annoying noise levels. The need for acoustic comfort,
on the part of those who live or work in buildings near a construction site, requires that all strategies be implemented within the construction site to ensure that the noise generated is as low as possible. The article describes the approach followed by a recent Italian standard regarding
the actions to be taken, by both the client and the contractor, to ensure that the construction site of the work commissioned by the client and realised by the contractor is as quiet as possible. The standard requires that the design of the construction site must include the use of both electrical
machines and shielding of proven effectiveness for these applications. The best results can only be seen with a preventive approach. It can be achieved if the Contractor not only understands that the site where he is working requires him to take special care to reduce noise, but also if he
demonstrates how he will put everything into good practice.
Investigation of effects of time of day and season on soundscapes in a wind farm
Authors: ROKITA Dagmar , UEBERLE Friedrich , KöPER Sebastian
Published: October 2024

Wind farms are often built in rural areas, on industrial sites or on the outskirts of urban areas. Therefore, wind farms often become part of soundscapes previously characterised by bio- and geophonic sounds. While the sound characteristics of wind turbines do not change much and only
depend on a few environmental parameters, biophonic and anthrophonic sounds vary greatly depending on the time of day or season. A series of soundwalks from December 2021 to October 2022 was used to investigate whether these fluctuations in the proportionate noise sources can be registered
via soundwalks and how this may affect the evaluation of the soundscapes in the wind farm. A total of 95 participants took part in 13 soundwalks, distributed over the four seasons and two different times of day. As expected, the main sounds observed in the wind farm were noise from the wind
turbines, natural noise, and traffic noise from a nearby motorway. Depending on the time of day and season, different dominance of noise types can be observed in the different soundscapes.
Fish feeding behavior quantification and automatic acoustic event detection: algorithmic optimization with deep learning
Authors: MYSORE GURUPRASAD Shreyas , BIES Laura , INGALE Mrudula , WERTH Dirk
Published: October 2024

In recent years, the integration of sensor processing technologies with intelligent feeding control systems has become crucial for enhancing recirculating aquaculture systems (RAS). Intelligent feeding control significantly improves profitability and animal welfare in aquaculture by
accurately monitoring feed intake and reducing waste. Acoustic methods have proven effective in automating feed monitoring, particularly in assessing feeding intensity. Automatic Audio Event Detection (AED) holds promise for identifying sound events associated with feeding activities, enabling
precise monitoring of feeding behavior and estimation of feed consumption through frequency-based feeding signatures. Advancements in sensor technologies and computational capabilities enable real-time collection, processing, and analysis of acoustic data. However, handling high volumes of
data with minimal latency and high accuracy poses challenges. To address these challenges, we propose a systematic approach: (1) Data preprocessing using wavelet transforms enhances efficiency and reduces computational overhead. (2) Data pruning focuses on informative features and reduces
input data dimensionality, improving classification accuracy. (3) We adopt a weakly-labeled semi-supervised learning model with Convolutional Neural Networks (CNNs) to detect feeding events, improving classification performance. (4) Ensemble learning combines multiple classifiers to mitigate
overfitting and enhance model generalization. Our methodology shows promise in accurately quantifying fish feeding behavior using acoustic signals.
Modal identification as a tool to increase the accuracy of acoustic absorption measurements in reverberation rooms
Authors: D'ORAZIO Dario , ZACCARINI Andrea , FALCIANO Fiorella
Published: October 2024

Measuring the acoustic properties of materials may be very challenging. At low frequencies, the sample may interfere with the room's modal behavior. When it occurs, the longest modal decays are influenced. Differences in reverberation time - empty Vs with-specimen conditions - are often
emphasized by these modal effects, and, as a matter of fact, the absorption coefficient may be overestimated. The present work aims to increase the accuracy through data augmentation at low frequencies. Modal identification was performed on measured impulse responses of porous specimens, allowing
the determination of modal-decay times within the third-octave bands of 80-160 Hz. A statistical analysis of natural modes highlights the modes whose decay exceeds the density function as outliers. This preliminary study ultimately provides some statistical considerations on the modal distribution
of decay times and their relationship with the reverberation time measured through the Schroeder integral.
Latency-free real-time auralisation in hemi-anechoic chambers
Authors: EDVALDSSON Garðar , XYDIS Achilleas
Published: October 2024

Real-time auralisation allows users to interact with a simulated acoustical room, providing a more responsive way of evaluating acoustical performance than pre- recorded auralisation. Nevertheless, real-time auralisation is computationally intensive and, therefore, susceptible to latency.
This paper presents a novel latency-free real-time auralisation method that enables users to auralise a simulated acoustical event with self-excitation more accurately than current methods. The method uses a loudspeaker system inside a hemi-anechoic chamber. By exploiting the inherent floor
reflection of the hemi-anechoic chamber, the impulse response can be trimmed to compensate for the total latency of the loudspeaker system. The method's validity is demonstrated with measurements presenting virtual wall reflections arriving at the correct time at the listening position. The
influence of the speaker placement regarding latency is discussed. This method enables users to evaluate a given response more accurately than conventionally possible.
Denoising by neural network for muzzle blast detection
Authors: PUJOL Hadrien , BEVILACQUA Matteo , THIRARD Christophe , MAZOYER Thierry
Published: October 2024

Acoem develops gunshot detection systems, consisting of a microphone array and software that detects and locates shooters on the battlefield. The performance of such systems is obviously affected by the acoustic environment in which they are operating: in particular, when mounted on
a moving military vehicle, the presence of noise reduces the detection performance of the software. To limit the influence of the acoustic environment, a neural network has been developed. Instead of using a heavy convolutional neural network, a lightweight neural network architecture was
chosen to limit the computational resources required to embed the algorithm on as many hardware platforms as possible. Thanks to the combination of a two hidden layer perceptron and appropriate signal processing techniques, the detection rate of impulsive muzzle blast waveforms (the wave coming
from the detonation and indicating the position of the shooter) is significantly increased. With a rms value of noise of the same order as the muzzle blast peak amplitude, the detect rate is more than doubled with this denoising processing.
Perceptual assessment of urban park audio-visual stimuli a comparison between Italian and Chinese groups
Authors: Lì Jian , CIOFFI Federico , MASULLO Massimiliano , MAFFEI Luigi , RUOTOLO Francesco , RUGGIERO Gennaro , RAPUANO Mariachiara , IACHINI Santa
Published: October 2024

Previous research demonstrated a preference for natural auditory stimuli over human-made sounds in urban park environments. However, little attention has been given to the perceived dimensions of these sounds and their consistency across diverse cultural groups. The present study aimed
at revealing possible culture differences among visual (Green, Square, Color) and auditory (Nature, Music, Anthropic) elements in urban parks. Eighty participants from both Chinese and Italian groups were administered a questionnaire to emotionally assess the stimuli. The differences in emotional
salience were found across both sensory inputs. For the visual inputs, Green parks were perceived as more pleasant than Colorful parks, and the latter were more pleasant than Square parks, indicating the more natural the setting, the more restorative the effects. An important finding refers
to the cross-culture consistency of the preferences. For the auditory inputs in urban parks, although both components of emotional salience were cross-culture consistent, some specific differences emerged.
Pedestrians' street-crossing decisions compared between conventional and electric vehicles
Authors: OBERFELD-TWISTEL Daniel , HUISMAN Thirsa
Published: October 2024

To safely cross a road before an approaching vehicle, pedestrians need to accurately judge the vehicle's motion. Recent studies from our lab demonstrated that the noise emitted by a vehicle conveys important information about its motion, particularly in the case of accelerating approaches.
Here, we compared street-crossing decisions between conventional (ICEVs) and electric vehicles (EVs) with or without AVAS sounds. The experiment presented high-fidelity audiovisual VR simulations of approaching vehicles, based on recordings of real ICEVs and EVs. The presented velocity profiles
included a large variation in acceleration rates, a = 0 to 4.4 m/s^2, and two velocities at the moment of the crossing decision (28 km/h versus 50 km/h). To investigate whether the lower sound level of EVs compared to ICEVs contributes to differences in crossing decisions, we additionally
presented a condition in which the sound levels were matched between vehicle types. All experimental conditions were presented in two modality conditions (auditory-only and audiovisual). We compare the crossing decisions between vehicle types, velocity profiles and level profiles in terms
of collision probabilities estimated from the measured psychometric functions. Preliminary results confirm differences between crossing decisions made in interaction with EVs compared to ICEVs, reduced in the level-matched conditions.
Prediction of vibro-acoustic sound emissions based on mapped structural dynamics
Authors: WURZINGER Andreas , HEIDEGGER Patrick , KRAXBERGER Florian , MAYR-MITTERMüLLER Bernhard , SIMA Harald , KALTENBACHER Manfred , SCHODER Stefan
Published: October 2024

In the product design of shell-like housing structures for vibrating bodies, acoustic emission plays a significant role in usability and customer comfort. Consequently, the prediction of the emitted sound, e.g., in the form of the radiated sound power, is desired in the earliest possible
stage of the development cycle. In industry, performing extensive acoustic testing using microphone arrays or laser scanning vibrometry is often time-consuming or infeasible, as it requires an acoustically treated measurement chamber and specific measurement equipment. On the other hand, accelerometer
data is more straightforward to obtain due to the lower cost of the sensors and relaxed constraints on the measurement chamber compared to acoustic measurements. Hence, this contribution utilizes available surface velocity data in an acoustic simulation of the free-field Helmholtz problem.
In doing so, it compares a conventional element-based and a mesh-less data-driven mapping technique to investigate the reduction of the number of provided sensor positions for the radiation problem. The open-source boundary element framework NiHu is used to give accurate predictions of acoustic
emissions over a wide frequency range. The approach is applied to an industrial problem and validated against microphone measurements.
Development of a conceptual framework for a new international standard on non-acoustic factors
Authors: WOODLAND Lisa , CHIENG Julia , FENECH Benjamin , LAVIA Lisa , ALETTA Francesco , KANG Jian , MITCHELL Andrew
Published: October 2024

The human response to a sound environment is influenced by factors that interlink the person, activity, and place. These factors are often referenced as discrete elements of the "context" in soundscapes, and as "non-acoustic factors" within the noise and health community.
Despite their importance, researchers and practitioners tend to use different terminology and methods for investigating them, which complicates evidence synthesis and recommendations for designing healthier sound environments. Since 2022, Working Group 68 within ISO TC 43/SC 1 has been developing
a new Technical Specification to standardise the definition and use of such non acoustic factors. Part 1, due for publication in 2025, will include a definition and a conceptual framework. As part of this work, we conducted a rapid scoping literature search to assist in the development of
the conceptual framework. Fourteen articles were shortlisted, which were used to draft a framework that reflects the definition of non-acoustic factors, including its main categories (personal, psychosocial, tangible/environmental, and situational) and the moderating and mediating role of
non-acoustic factors on the human perceptual and affective response (emotional and behavioural) and associated health outcomes.
Can we be confident about ship noise measurements?
Authors: PERRIER DE LA BATHIE Cécile , CAUCHY Pierre , ST-ONGE Guillaume , MERCURE-BOISSONNAULT Pierre , LAFRANCE Sylvain
Published: October 2024

Increased maritime traffic is leading to more underwater noise. Despite the use of a standardized protocol (ANSI/ASA S12/64-2009), measuring ship noise is complex, as it is difficult to follow the protocol in real-life conditions. The Marine Acoustic Research Station (MARS) project
(www.projet-mars.ca/en) designed a recording station and a measurement protocol that follows closely the international standard. The station operated during summer/fall in 2021, 2022 and 2023 in the Laurentian Channel in the St. Lawrence Estuary (eastern Canada). Four dedicated missions were
organized, during which the R/V Coriolis II was measured repeatedly, generating a database of 239 measurements. In this study, we assess the measurement repeatability of the MARS station, comparing simultaneous measurements from identical systems, as well as repeated measurements at varying
speeds and distances. We quantify the measurement uncertainties associated to the hydrophone configuration and the measurement protocol. Our results illustrate how array redundancy allows to identify and mitigate hardware-related issues and to reduce the duration of the measurement, a costly
parameter. We quantify the repeatability of single measurements within the MARS station, we discuss the implications regarding our ability to validate noise reduction actions from ~3 dB and we propose a measurement protocol to further reduce this limit.
Evaluation of the effect of respiratory airflow on captured speech quality: application to pop filters
Authors: JOUBAUD Thomas , ZIMPFER Véronique
Published: October 2024

Recording speech is often a matter of proper experimental design to obtain the best signal quality. This notably includes appropriate microphone positioning and gain adjustment. However, some radio communication devices require that the microphone be placed in a very close proximity
to the mouth, therefore capturing the respiratory airflow, as well as the air bursts from plosive consonants. In this paper, we assess an objective evaluation method for the quality of speech signals captured in such adverse conditions. It employs an artificial mouth coupled with a steady
airflow to compute the Speech Transmission Index (STI). We apply this method to the evaluation of four commercially available pop filters. The addition of a 30~L/min airflow reduces the STI with the microphone alone from excellent to fair. With soft fabric filters, we gain back the original
STI, while it remains very slightly degraded with a metal mesh filter. The objective metric is finally confronted with a listening test. The perceived quality of simulated samples with the added airflow is similar to the STI results. However, no significant difference between the filters is
found with real speech samples containing plosive consonants and no respiration noise.
Sound quality evaluation of small fan noise by tonal components
Authors: MINORIKAWA Gaku , NAKANO Takefumi
Published: October 2024

As Covod-19 has made online meetings from home offices the norm, the noise from small fans installed in information devices has increasingly become a factor disrupting a comfortable environment. In addition, as global warming accelerates, the use of new small fans called wearable fans
has expanded, and the distance between small fans and humans has become even closer. In this study, we investigated whether T-TNR and T-PR, which are two methods for evaluating the tone characteristics of small fans, can be applied to the noise of projectors and wearable fans. We investigated
a method for selecting dominant components and searched for a method for determining the harshness threshold using T-TNR and T-TPR.
Far-field directivity estimation with a cube-shaped array of 256 MEMS microphones
Authors: HARTENSTEIN Matthieu , LUIZARD Paul , SILVA Fabrice , OLLIVIER Francois , OLLIVON Christian , MOINGEON Hélène , PACHEBAT Marc , PINHèDE Cédric , SOKPOLI Augustin , MEINNEL Marco
Published: October 2024

The far-field directivity function (FFDF) of a sound source characterises the angular dependence of the acoustic fields far away from this source. This function can be estimated by performing a spherical wave expansion (SWE) of the sound field from pressure measurements distributed
around the source. The truncation order of the SWE is a critical parameter that depends on the number of measurement points and on the spatial sampling scheme used for the measurements. Unfortunately, for irregular sampling schemes, no theoretical result allows to determine a truncation order.
In this work, a surrounding cuboid microphone array composed of 256 MEMS microphones is deployed. A cross-validation framework is used in order to determine an optimal truncation order for the SWE of the field radiated by a test source. The quality of the reconstructed field is assessed on
the frequency range 100-5000 Hz. Finally, the estimated SWEs and far-field directivities are compared to an analytical model of the test source.
Ultrabroadband sound control of 3D spaces using plasmacoustic metalayers
Authors: SERGEEV Stanislav , DONALDSON Mark , LISSEK Hervé
Published: October 2024

Controlling sound in three-dimensional spaces is a complex task, challenged by the intricacies of acoustic modal structures, the variety of noise sources, and the propagation of waves. This research analyzes the influence of local impedance control on the global sound field within a
parallelepipedal volume characterized by high reverberation. The employed electroacoustic transducer is based on a corona discharge mechanism and utilizes the Plasmacoustic Metalayer concept. The sound field is regulated directly by the interaction between the air particles and the ionized
air produced in the discharge area. The inertia-free plasmacoustic Metalayer contributes to an increased control bandwidth. Experimental tests conducted with several actively controlled transducers distributed throughout the volume demonstrate the dampening of multiple modes. This leads to
a more consistent frequency response and a broadband reduction in sound pressure levels across the entire space, demonstrated here up to 700 Hz. Numerical simulations suggest that such a systemcan also be potentially efficient in a more realistic space such as a vehicle cabin.
Low frequency, broadband and thin acoustic metamaterials for acoustic insulation
Authors: AYYASH Nadeen , LECOQ Damien , LAGARRIGUE Clément , PELAT Adrien , GAUTIER Francois
Published: October 2024

Elastic and locally resonant metamaterials can be used to improve the acoustic insulation properties of panels, particularly at low frequencies. Among the possible architectures, we are interested in the case of a very soft panel consisting of a porous material in which a periodic distribution
of cylindrical inclusions is inserted. It has recently been established (JSV 571 (2024) 118005) that this configuration gives rise to a large and low-frequency transmission dip, explained by the coexistence of an elastic band gap and the destructive interference resulting from the interaction
between an elastic resonance mode of the skeleton and a rigid body mode of the inclusions. The paper aims to describe the essential physical mechanisms involved in using a minimal lumped element model, the characteristics of which are extracted from the cell modes. The relevance of the minimal
model is validated utilizing a comparison with reference results obtained using the finite element method. This approach focuses on the mechanisms involved and is not constrained by the choice of a particular geometric configuration (exact shape and size of the inclusion), allowing it to evolve.
Vibro-acoustic behavior of a permanent magnet synchronous electrical machine: Influence of rotor displacement on Maxwell's pressures
Authors: POUPON Thomas , ABDELNOUR Nicolas , GIVOIS Arthur , LANFRANCHI Vincent , CHAZOT Jean-Daniel , HAMITI Tahar
Published: October 2024

Electric machines are often perceived as silent, yet the noise they produce has become a significant issue. This paper presents a focused approach to understanding the source of this noise, aiming to enhance machine design. Our study centers on the vibratory model of a permanent magnet
synchronous electric machine. The stator and rotor components (shaft, laminations, magnets, and flexible bearings) are modeled using finite element analysis. We calculate the magnetic forces from Maxwell's pressures, which are analytically determined using the subdomain method. A key aspect
of our study is the consideration of dynamic eccentricity. The paper explores how the vibratory responses of the rotor affect theses stress and how to address the complexity of magneto-mechanical coupling. Our findings reveal that the magneto-mechanical coupling of the rotor directly and significantly
impacts Maxwell's pressures, and has to be taken into account to characterize the dynamics of rotor and stator.
Understanding human responses to air source heat pump noise: examining tonal changes and operating cycles
Authors: ACUN Volkan , BARTON Lucy , COX Trevor , GRAETZER Simone , HARGREAVES Jonathan , TORIJA MARTINEZ Antonio , RADIVAN Max , WADDINGTON David , WONG-MCSWEENEY Daniel
Published: October 2024

Air Source Heat Pumps are pivotal in the Government of the United Kingdom's target of achieving net zero carbon emissions by 2050. However, their widespread adoption faces challenges, with noise being among the main barriers to entry and a restricting factor at the planning stages.
This study addresses concerns regarding noise propagation from outdoor units to indoor environments through a two-part experiment, aiming to capture human responses to Air Source Heat Pump noise based on the changes in the characteristics of noise emissions at various operating conditions,
background noise levels, and source distances. The first part evaluates peoples' responses under static operating conditions to 20-second recordings, using the Self-Assessment Manikin scale and an annoyance scale. Following each recording, they used the Self-Assessment Manikin pictorial scale
and an annoyance scale to report their response. In the second part, responses to transient Air Source Heat Pump operation cycles are assessed using 60-second recordings. Participants evaluated each recording at two points: after a transition in the operating cycle and at the end of the recording.
The findings of the study provide insights into the human response to heat pump noise, essential for developing strategies to facilitate wider Air Source Heat Pump adoption.
Exploring the effects of phase delay on propeller noise: an experimental study in tandem configuration
Authors: PAGLIAROLI Tiziano , CANDELORO Paolo , DEL DUCHETTO Fabio , ROSSIGNOL Karl-Stéphane , YIN Jianping
Published: October 2024

Noise cancellation is a revolutionary control strategy, so effective that it has been integrated into high-end headphones. Implementing this approach on drones may seem challenging, but at the same time, it is highly appealing. The idea is to use some rotors, which constitute the main
noise source, as a secondary pressure wave to eliminate the noise emitted by the entire propulsion system by inducing destructive interference among the individual sources. Implementing this kind of technology requires a significant understanding of the interaction mechanism of pressure waves
emitted by the blades. The associated signature is not sinusoidal and exhibits strong directivity. This article will clearly demonstrate the potential of this approach by focusing attention not only on the effects but also on the nature of the interference mechanism. This finding is pivotal
for the design of an active noise control system.
Numerical study of thermo-viscous effects in acoustic materials using linearized Navier-Stokes equations
Authors: EL HAJJ Elissa , RASTEGAR Niloofar , SALINAS Manuel Flores , FOTSING Edith Roland , ROSS Annie , VIDAL David
Published: October 2024

Acoustic materials, characterized by small-scale structures, require a detailed understanding of dissipation effects within the viscous and thermal boundary layers where most of the dissipation takes place. Despite the prevalent assumption of lossless or isentropic conditions in many
applications, a comprehensive study of regions where thermal and viscous losses occur is crucial, particularly in scenarios where wall-induced losses are significant. Bridging this gap, the study aims to investigate these losses in various structures to guide the development of innovative
acoustic materials. To achieve this objective, the Linearized Navier-Stokes Equations (LNSE) solver from the finite element software COMSOL is employed to determine the absorption coefficients and to identify predominant regions of thermal and viscous losses. The model is validated using experimental
and published data. The study effectively reveals specific regions where these losses significantly dominate, highlighting their critical influence on acoustic material performance. Although the structures are simplified to 2D models to balance physical details with computational feasibility,
the ability to identify dominant loss regions marks a significant contribution to the field and paves the way to refine the design of acoustic materials.
Thermal-biomechanical manikin applied in turbulent airflow and vibration systems in transient conditions
Authors: CONCEIçãO Eusébio , CONCEIÇÃO Margarida , CONCEIÇÃO Mª Inês , LÚCIO Mª Manuela , AWBI Hazim
Published: October 2024

This paper applied a thermal-biomechanical manikin in turbulent airflow and vibration systems in transient conditions. This numerical model evaluated the thermal and biomechanical components to which the human body is subjected. The first one considers the first-order equations systems
based on the thermal numerical model, while the second one considers the second-order equations systems based on the vibration numerical model. This second-order equations system is converted into a first-order equation system. The resolution of the thermal and biomechanical numerical models
is made through the Runge-Kutta-Fehlberg method with error control. The thermal numerical model is used in the study of the steady-state and transient conditions when the skin is subjected to mean and turbulent airflow. The biomechanical numerical model is used in the study of the human body
vibrations applied to the feet, that a standing person is subjected, using periodical and random vibration signals of the floor. The thermal analysis shows that with an air fluctuation velocity, the skin temperature reduces slightly. The amplitude of the vibration in the lower body section
is higher than in the upper body section. The introduction of the randomised vibration, in the periodical vibration, the human body vibration increases the fluctuation level.
Research on the regulation of emotions in elderly people through bedroom audio-visual environments
Authors: MU Jingyi , LI Peiyu , FENG Yimeng , ZHANG Cheng
Published: October 2024

The indoor environment of buildings has a long-term impact on the psychological and physiological state of people, and a good indoor environment can help the physical and mental health of the elderly. As the mobility of the elderly weakens, the indoor visual and auditory environments
are important channels for them to acquire external perceptions. In order to investigate the effects of visual and auditory environments on the psychological (positive and negative emotions) and physiological (heart rate) states of older adults in their bedrooms, the study designed an audio-visual
interaction experiment, selecting three common sounds preferred by older adults and six visual scenes that included two types of visual factors , to measure the emotions and heart rate changes under different sound and visual interaction conditions. The study revealed that natural sounds were
more effective in positively modulating mood in warm-toned rooms, while artificial sounds were more appropriate for cool-toned rooms. Regardless of the type of therapeutic sound environment, the addition of greenery significantly contributes to mood regulation in older adults. Combining sound
environments with visual factors can be an effective design strategy to promote the physical and mental health of occupants.
Characterization, modeling and prediction of foam-formed softwood fiber sound absorption
Authors: HELDMANN Janis , CUCHARERO MOYA Jose , LOKKI Tapio
Published: October 2024

The transition towards building materials with low or negative carbon-dioxide footprint is a pressing topic in nowadays society. Materials for thermal and acoustic insulation are among those attracting a growing number of research publications. Commonly used materials in the building
sector are mostly mineral wools which demand huge amounts of energy during production by melting sand or stone. Cellulose-based materials are a promising substitute for the current market leaders. These materials are able to reach negative carbon footprints due to low embodied energy and their
ability to store carbon dioxide in buildings for decades. Predicting the sound absorption behavior prior to manufacturing can further improve their usability. This study delves into the prediction and characterization of wood-based pulp fiber foams and their acoustic properties. By comparing
analytical models, semi-phenomenological models and experimental measurements the prediction of sound absorption based on fiber diameter and bulk density is evaluated. The findings reveal that refining a recent analytical model for natural fibers through parameter fitting to non-acoustic parameters
yields improved accuracy in predicting sound absorption curves. While the accuracy declines towards higher densities, this work lays the groundwork to create environmentally sustainable sound absorbers with carefully tailored sound absorption properties.
Noise-conscious driving behaviour in road traffic and the potential influence of visual cues
Authors: CZUKA Martin , CONTER Marco , FIEBIG André , MOSHONA Cleopatra , CHUDALLA Michael , STRIGARI Fabio
Published: October 2024

Careful driving in road traffic improves safety as well as potentially promotes ecological and economical driving behaviour. However, associated aspects such as anticipatory driving, consistent driving speed, and early upshifts when switching gears also influence individual noise emissions.
While noise impact assessment often focuses on those affected, little research has been conducted on noise-conscious behaviour. In this work we present a driving experiment conducted in conventional road traffic which investigates potential strengthening of active self-regulation due to visual
cues. Participants of the intervention group were provided with continuous visual feedback about their car's noise emission based on their driving behaviour, and were confronted with two static information signs placed along the driving route. This paper comprises the methodological approaches
as well as results of the experiment. This work contains parts of the commissioned research project FE-Nr. 69.0013/2022, which is funded by the German Federal Ministry for Digital and Transport represented by the German Federal Highway Research Institute. The responsibility for the content
lies solely with the authors.
Towards multisensory control of physical modeling synthesis
Authors: JANKOWIAK Loïc , HAN Han , LOSTANLEN Vincent , LAGRANGE Mathieu
Published: October 2024

Physical models of musical instruments offer an interesting tradeoff between computational efficiency and perceptual fidelity. Yet, they depend on a multidimensional space of user-defined parameters whose exploration by trial and error is impractical. Our article addresses this issue
by combining two ideas: query by example and gestural control. Prior publications have presented these ideas separately but never in conjunction. On one hand, we train a deep neural network to identify the resonator parameters of a percussion synthesizer from a single audio example via an
original method named perceptual-neural-physical sound matching (PNP). On the other hand, we map these parameters to knobs in a digital controller and configure a musical touchpad with MIDI polyphonic expression. Hence, we propose a multisensory interface between human and machine: it integrates
haptic and sonic information and produces new sounds in real time as well as visual feedback on the percussive touchpad. We demonstrate the interest of this new kind of multisensory control via a musical game in which participants collaborate with the machine in order to imitate the sound
of an unknown percussive instrument as quickly as possible. Our findings show the challenge and promise of future research in musical "Human-AI parternships".
Experimental verification of the variability of amplitude modulation (AM) from wind turbines in relation to its assessment for annoyance
Authors: CZAPLA Marcjanna , WSZOłEK Tadeusz , CZAPLA Marcjanna , WSZOłEK Tadeusz
Published: October 2024

The analysis of the influence of amplitude modulation (AM) on the annoyance of noise generated by wind turbines (WT) is still the subject of numerous studies. However, there is still a lack of widely accepted quantitative methods that would determine the degree of influence of modulation
phenomena on noise perception. The study analyzed the variability of the depth of AM over time within different frequency-ranges. The research was based on long-term measurements at selected measurement locations. Long-term measurement ensured consideration of diverse propagation conditions.
The collected data were segmented into time intervals, which included basic AM parameters - depth, modulation frequency, and frequency band in which the AM was observed, as well as wind speed and direction. Statistical analysis of the gathered dataset was used to assess the regularity of distinguished
AM parameters in correlation with WT noise energy values and recorded non-acoustic parameters. A significant variability of AM depth was observed depending on the frequency band, masking level, and position relative to the wind direction. By adopting a criterion for assessing the annoyance
of WT noise (according to AMWG) with a threshold depth of AM not less than 2 dB, it was noticed in over 30% of the analyzed intervals.