bluuebunny/crossref_metadata_2025 huggingface dataset:
Influencing parameters and indicators assessment for aircraft external noise tonality perception
Authors: BOULLET Isabelle , PELLEGRIN Nathalie
Published: October 2024

Reducing the annoyance related to the noise generated by aircraft flyovers near airports is a major concern of the aeronautical industry. Noise source reduction is one of the pillars of the balanced approach, but further research is still needed to understand and reduce unpleasantness
and annoyance due to aircraft noise. From a psychoacoustics point of view, it is particularly important to understand and assess the effects related to perceived phenomena such as tonality which increases unpleasantness at similar noise levels. This article presents the results of a parametric
study looking at the influence on tonality of frequency, emergence level and number of harmonics and the assessment of tonality indicators. The particularity of this study is the non stationarity of the tonal noise due to the Doppler effect and the low frequency investigation.
Modelling of courtyard acoustics using the nodal discontinuous Galerkin finite element method to validate a newly developed PML
Authors: FERIANI Sophia Julia , ENGSIG-KARUP Allan P. , COSNEFROY Matthias , PIND Finnur , XIA Yuanxin , JEONG Cheol-Ho
Published: October 2024

Evaluating the acoustics of courtyards has gained increasing attention from a sustainable urban design perspective, which requires numerical predictions tools for estimation of noise pollution and assessment of the influence of acoustic conditions. Accurate modeling of the acoustics
of a courtyard is scarce because of the variety of factors to include: meteorological effects, building material properties, and geometry of the inner façades. We consider the nodal Discontinuous Galerkin finite element method framework in a 3D static and uniform medium and use it to
model the sound propagation in a courtyard. A new and efficient Perfectly Matched Layer formulation is implemented at the open boundary of the courtyard model to absorb outgoing acoustic waves and this way limiting the size of the computational domain. The numerical results are validated against
experimental measurements carried out in a scaled model of a courtyard with an elementary design to implement an accurate corresponding numerical model. The experiments were conducted in an anechoic chamber where the meteorological effects are controlled, and the courtyard facades are modelled
as flat surfaces with known material properties.
Beyond loudness: development of a holistic solar-powered urban soundscape sensor
Authors: CASSENS Lion , KROESEN Maarten , CALVERT Simeon , VAN CRANENBURGH Sander
Published: October 2024

Low-cost sensor networks have increasingly been used to monitor noise pollution as an alternative to certified sound level meters. Existing sensor networks monitor loudness and, in some cases, classify sound sources. Most sensors do not capture metrics that are more representative of
the human perception of sound, require a permanent power supply, or are relatively expensive. We develop an energy-efficient soundscape sensor with the goal of recording metrics complementary to loudness. We have implemented metrics from psychoacoustics and metrics inspired by biodiversity
research, such as sharpness, intermittency, and acoustic entropy. Furthermore, the sensor predicts the source of sound events. For privacy-preservation, all audio is processed directly on the sensor. The sensor is based on a low-power microcontroller (ESP32-S3), available for a fraction of
the cost of a Raspberry Pi, which is often used for sound source prediction. Finally, the sensor is solar-powered and therefore easy to install for research purposes at places without direct access to the power grid. A temporary deployment of several sensors in Amsterdam, the Netherlands,
is planned
Geometrically nonlinear vibrations of plate embedding a large circular acoustic black hole
Authors: DENIS Vivien
Published: October 2024

The concept of acoustic black hole (ABH) designates a decrease in bending stiffness and a localized added damping within a thin structure aiming to localize and efficiently dissipate vibrations. The small thickness results in large amplitude vibrations, which suggests to take into account
geometrical nonlinearities. The subject has been previously studied on a beam with a one dimensional ABH. Previous research studied a geometrically nonlinear plate embedding a one dimensional ABH. This study aims at solving the Von Karman equations for a variable thickness plate, via a modal
projection using the eigenmodes obtained with a finite element model. The use of a finite element model in this context allows to take into consideration more complex geometries. The methodology is then applied to a rectangular plate embedding a large circular ABH with added damping. The convergence
of the nonlinear coefficients is studied and time domain computations show the relative importance of the geometrical nonlinearity.
Herschel-Quincke filters adapted to bending waves in beams and plates
Authors: AVETISOV Stepan , PELAT Adrien , GAUTIER François , SOROKIN Sergey
Published: October 2024

A Herschel-Quincke (HQ) filter is a device for controlling the transmission of guided waves: by adding one or more auxiliary branches to a waveguide, it is possible to construct delay lines, which induce destructive interference effects and consequently zero-transmission phenomena at
targeted frequencies. We explore the use of this principle in the context of elastic waves in beams.The dispersive nature of bending waves and their coupling with longitudinal waves introduces complexity into the tuning of the zero transmission frequencies. A model, developed within the framework
of Timoshenko's beam theory, provides the scattering matrix of an HQ filter composed of several branches. The model is confirmed by FE and thus demonstrates the interest of the approach for the control of vibrations. The architecture of the HQ device and the modelling approach are extended
to a 3 branches configuration. The properties of the filter are analysed, leading to a discussion of the advantages and disadvantages of the HQ strategy.
And for a few more decibels
Authors: BODIN Jean-Baptiste , MERCIER Stéphane
Published: October 2024

Sound diffusion in cinemas is nowadays subject to a bidding war in the low-frequency range. Through various projects and recent experiences, we offer an overview of this evolution, its effects and the solutions found to reconcile often antagonistic uses. In particular, we will present
the integration of a city cinema, one room of which is equipped with a Dolby ATMOS system, into a housing program. We will also look at the specific features of the recent Dolby Cinema system in terms of low-frequency sound diffusion and its impact on the cinema itself and its surroundings,
through a recent installation of such a system.
Experimental study on heavy-weight floor impact sound control of vibration-proofed tatami mats constructed widely on a concrete slab and dry floating floors
Authors: TOMITA Ryuta , OKUYAMA Yuta , ABE Kyoko
Published: October 2024

This study investigates the structural properties of a 55-mm thick tatami mat floor, a flooring prevalent in Japan. Building on previous research that introduced a tatami mat floor designed for vibration isolation, this work extends the investigation to heavy-weight floor impact sound
mitigation on tatami mats measuring 900 × 1800 mm. The current study expands the tatami mat size to 2700 × 2700 mm and evaluates the sound insulation performance of vibration-isolated tatami mats placed on a concrete slab and dry floating floors. The experimental findings are summarized
as follows: (1) The deployment of vibration-proofed tatami mats atop dry floating floors yielded notable improvements under tire-induced vibrations, achieving reductions of 4-6 dB in the 63-Hz band, 3-7 dB in the 125 Hz band, 4-6 dB in the 250 Hz band, and 6-9 dB in the 500 Hz band. (2) Similarly,
with rubber ball-induced vibrations, installing vibration-proofed tatami mats on dry floating floors resulted in sound level reductions of 2-3 dB in the 63 Hz band, 4-5 dB in the 125 Hz band, 8 dB in the 250 Hz band, and 8-11 dB in the 500 Hz band.
Experimental validation of vibration similitude laws for stiffened panels excited by a turbulent boundary layer
Authors: PLOUSEAU-GUÉDÉ Xavier , BERRY Alain , MAXIT Laurent , MEYER Valentin , MOUGEY Anaïs , ROBIN Olivier
Published: October 2024

Stiffened structures excited by a turbulent boundary layer (TBL) occur in many engineering applications, particularly in the aerospace and naval sectors. The structures encountered in these applications are generally large and complex, and carrying out experiments in order to characterize
their vibration response can be costly, time-consuming and difficult. To overcome these constraints, the similitude theory can be used to estimate the response of a full scale structure from the response of a reduced scale structure. A simplifying step to determine these similitude laws for
stiffened panels consists in modeling the panel as an equivalent orthotropic panel. Then, using the governing equation of the orthotropic panel and considering the TBL excitation, the vibration similitude laws are derived implying similitude conditions to be respected on geometrical and material
properties of the structure as well as flow velocity. In this paper, we present the developments of these similitude laws and an experimental validation for panels in air. The similitude conditions are discussed to adequately choose the properties of scaled stiffened panels. Experimental results
are presented to show that the structural response of the reference panel can be recovered from the response of the reduced scale panel using the related scaling laws.
Deep learning methods for modeling infrasound transmission loss in the middle atmosphere
Authors: LE PICHON Alexis , JANELA CAMEIJO Alice , AKNINE Samir , YSKLAB Youcef , ARIB Souhila , BRISSAUD Quentin
Published: October 2024

Accurate modeling of infrasound transmission losses (TLs) is essential to assess the performance of the global International Monitoring System (IMS) infrasound network. Among existing propagation modeling tools, parabolic equation method (PE) enables TLs to be finely modeled, but its
computational cost does not allow exploration of a large parameter space for operational monitoring applications. To reduce computation times, Brissaud et al. (2022) explored the potential of convolutional neural networks (CNNs) trained on a large set of regionally simulated wavefields (>1000
km from the source) to predict TLs with negligible computation times compared to PE simulations. However, this new method shows difficulties in upwind conditions, especially at low frequencies, and causal issues with winds at large distances from the source affecting ground TLs close to the
source. In this study, we have developed an optimized CNN network designed to minimize prediction errors while predicting TLs from globally simulated combined temperature and wind fields spanning over propagation ranges of 4000 km. Our approach enhances the previously proposed one by implementing
key optimizations that improve the overall architecture performances. The implemented model predicts TLs with an average error of 20 dB in the whole frequency band (0.1-4 Hz) and explored realistic atmospheric scenarios.
Vibration behavior of a microperforated plate within an acoustic nonlinear framework
Authors: GALLERAND Lucie , LEGRAND Mathias , DUPONT Thomas , PANNETON Raymond , LECLAIRE Philippe
Published: October 2024

Microperforated plates (MPP) can add substantial damping in the low-frequency range. MPP are known to dissipate energy through thermo-viscous interactions between shearing adjacent fluid layers near the perforation solid walls. Under linear operating conditions, a previous work carried
out by the authors showed that the added damping reaches a maximum at a characteristic frequency which solely depends on the perforation parameters. However, MPP is also suitable in environments subject to high levels of mechanical excitation and, consequently, high fluid velocity within the
perforations. Two types of nonlinearities should then be considered: (1) an acoustic nonlinearity induced by high fluid velocity, and (2) a nonlinearity induced by large structural displacements. This work only explores the former. The acoustic nonlinearity is modelled by the Forchheimer resistivity
correction, a function of the fluid-solid relative velocity in the perforations, introduced into the equations subsequently solved numerically. Experimental measurements using a laser vibrometer on a perforated cantilever beam validate the proposed model. Results show that, under high excitation
levels and at the characteristic frequency, the maximum added damping can reach a maximum, depending on the MPP parameters, at a critical value of the relative fluid-solid velocity.
Sound of Democracy: Towards the democratisation of standards for soundscapes
Authors: KOPLJAR Sandra , GRIMSHAW-AAGAARD Mark , GUSTAFSSON Clara , GROTH Sanne Krogh , RONCHI Enrico , HöJLUND KOLDKJäR Marie , MATTISSON Kristoffer , MUKHTAR-LANDGREN Dalia , DODDS Phil
Published: October 2024

With this paper and the accompanying audio paper, our aim is to explore the juxtaposition of sound and democracy. Recognizing the multifaceted nature of this field, we approach it through the notion of care and an empirical analysis of democratic implications of trying to regulate sound
in public spaces. We examine standards as one example of the many attempts to control sound in both public and private spaces. Standards are used to categorize, govern, and control. They are also tools to assess and characterise. As policy tools they raise democratic questions relating to
who developed them, when and how they are used. Using the example of a shopping mall, we explore the democratic values reflected in the standards through their development and application through an inter-disciplinary perspective. We used the audio paper format to move from discussing the
process of developing the soundscape standards to applying them in a real-world setting, ultimately exploring the consequences of such standards from the perspective of democratic values. The present written paper is a longer elaboration on methodology and theory as a compliment to the audio
paper which develops the discussion and analysis.
A new method for the characterization of perforated facings using a wide frequency range Impedance Sensor
Authors: DALMONT Jean Pierre , POULAIN Nicolas , LE ROUX Jean Christophe
Published: October 2024

Perforated facings (like fabrics, micro-perforated screens, ...) are widely employed in noise reduction solutions. Following previous works, it has been shown that they can be described as a porous media with identical cylindrical perforations. Then, a classical five parameters JCA
model can be employed to predict the acoustical behaviour of perforated facings and, due to their small thicknesses, these five parameters can be obtained from only two independent quantities: the perforation average radius and the perforation rate. The CTTM and LAUM have recently developed
a new approach for the measurement of JCA porous model parameters. This approach relies on the properties of two innovative apparatuses: an Impedance Sensor which allows for accurate impedance measurements over a wide frequency range combined with a patented compact anechoic termination. These
devices are used to propose an improvement of an existing method for perforated facings characterisation. By using a non-resonant acoustic load and the Impedance Sensor, an accurate estimation of facing bulk magnitude can be done over a wide frequency range. Then the possible impact of the
facing vibrational mode and of the acoustic load resonances is reduced, allowing for a more accurate estimation of facing parameter. Results are presented and discussed for different samples.
Railway curve squeal detection and tonal analysis
Authors: TORATTI Leevi , ASPLUND Matthias , THIERY Florian , CHANDRAN Praneeth , JOHANSSON Örjan , RANTATALO Matti
Published: October 2024

Railway curve squeal is a loud tonal noise generated by instabilities in the wheel-rail contact of railway vehicles while negotiating tight curves. The emitted noise is perceived as highly disturbing and contributes to noise problems in urban environments. Traditional monitoring of
squeal occurrence involves analyzing train pass-by sound measurements. Such monitoring system is sensitive to high background noise which can pose a problem in urban environments with limited possibilities for suitable microphone placement. To overcome these issues, an alternative approach
to detect curve squeal from rail vibration measurements is investigated. This comprises a simple and practical monitoring solution virtually unaffected by sound disturbances from the surroundings. Furthermore, this method can identify whether squeal noise occurs on the low or high rail. Field
measurements involve a two-part analysis: 1) the development and validation of a method for detecting squealing events from rail vibrations, and 2) identifying tonal components from the measured signals. Results from the first part suggest that curve squeal can be detected from rail vibrations
and the specific rail where squeal is generated can be identified. In the second part, specific frequency regions where squeal tonal components tend to emerge are recognized.
Design optimization of phononic-fluidic resonator systems
Authors: BELAHURAU Yauheni , LUCKLUM Frieder
Published: October 2024

Phononic-fluidic resonators utilize an acoustic fluid domain as a defect inside a solid metamaterial lattice, which can be used used to precisely measure acoustic properties of liquids. The design goal is to offer ideal boundary conditions for the acoustic resonator by matching defect
resonance with phononic band gap. The design space of metamaterial or phononic crystal and fluidic resonator is nearly unlimited, especially when utilizing fully three-dimensional structures. In this work, we explore numerical shape and topology optimization to focus acoustic energy into the
fluid domain and maximize the quality factor of the defect resonance. This requires the use of complex multi-frequency objective functions, while taking into account practical limits such as finite size and losses in the fluid and solid domains. Results highlight notable but limited improvements
of quality factor with shape optimization starting from an initial design constrained by the maximum deformation possible. On the other hand, topology optimization results offer unique and unexpected ideas, and thus a deeper dive into the design space.
Experimental insights on sound characteristics and psychoacoustic parameters on axial fan performance in heat pump systems
Authors: SEN BULENT , BILGIN Eda
Published: October 2024

This study focuses on the computational fluid dynamics (CFD) simulations and experimental measurements of the sound power level of an axial fan used in heat pump systems. Calculations and experiments were systematically conducted for three different fan-evaporator distances. CFD results,
including kinetic energy and velocity vector values, were obtained and compared with experimental sound power results. The relationships obtained were thoroughly examined in terms of their impact on psychoacoustic parameters. This study was conducted to contribute to the understanding of fan
performance and sound characteristics in heat pump systems. The results provide crucial information for users aiming to reduce air-source noise and determine optimized fan-evaporator distances for acoustic comfort.
Psychoacoustic metrics and affective responses in indoor soundscapes: Implications for restorative soundscapes
Authors: ALGARGOOSH Alaa , ASTROM Hector , ALRASHEED Hend
Published: October 2024

This study investigates the links between psychoacoustic metrics and affective responses in indoor soundscapes, guided by the ISO/TS 12913 standard. Through the analysis of an indoor soundscapes dataset, we examine how various psychoacoustic metrics, namely sharpness (S), fluctuation
strength (FS), and roughness (R), influence affective responses such as pleasant and eventful. Our research reveals that eventful and annoying soundscapes show higher values of (S), (FS), and (R). Conversely, pleasant soundscapes tend to show lower values in these metrics. The findings suggest
that while these metrics can be effective in designing eventful soundscapes, they may be less useful for creating pleasant acoustic environments. This study contributes to the understanding of the applicability of current psychoacoustic metrics for the type of soundscape intervention and calls
for the development of new psychoacoustic metrics to design restorative soundscapes that enhance well-being.
Optimization of graded and partial metamaterial treatments for enhanced broadband sound insulation in partition panels
Authors: GIANNINI Daniele , SCHEVENELS Mattias , REYNDERS Edwin P.B.
Published: October 2024

Resonant metamaterials can achieve unprecedented vibroacoustic attenuation in lightweight partition panels through small resonators attached on a subwavelength scale. Conventional metamaterial treatments are effective only in a narrow band and typically cover the entire panel surface,
posing important challenges for industrialization due to manufacturing and cost constraints. To address these issues, in this study we propose graded and partial metamaterial treatments, which are selectively distributed where they are the most effective, avoiding unnecessary coverage, and
include a spatially varying resonance frequency for broadband effectiveness. The related design challenges are tackled by developing a numerical methodology that simultaneously optimizes the distribution and the grading of the treatment. The optimization objective is to maximize the broadband
diffuse sound transmission loss (STL) of the metamaterial panel, while constraining the maximum fraction of treated area. Leveraging effective medium modelling, the approach efficiently incorporates local changes in the effective mass density of the metamaterial panel to represent partial
treatments. Different design cases are considered for different target bands and panel dimensions. Results demonstrate that graded partial metamaterial treatments can achieve broadband improvements with a limited treated area, effectively suppressing the STL dips due to the modes of the host
panel and to coincidence effects.
Analysis of the Gaussian assumption of single sound source measured and processed through sound level meter
Authors: DE SALVIO Domenico , D'ORAZIO Dario , GARAI Massimo
Published: October 2024

Machine learning (ML) techniques are constantly growing in acoustics. Such methods exploit large databases to train algorithms and earn complex feature correlations. The primary goal is to obtain inferences and predictions. Thus, ML often exploits statistics, and understanding the data
distribution becomes fundamental when analyzing the available data. However, it is well-known that only some common methods can be used with large databases, e.g., normality tests are discouraged. The present work aims to explore the Gaussian assumption underlying a validated clustering technique
used in long-term monitoring of sound level meters. The Gaussianity of single sound sources is analyzed through normal tests, normal probability plots, cumulative distribution functions, and high-order moments. The analysis involves a real-world measurement carried out through a sound level
meter and speech recordings obtained from a common database used in machine learning. Results show that a single sound source can be deemed Gaussian in sound level meter long-term measurements, leading to important insights concerning the choice of algorithms.
Robot control architecture for autonomous sound source mapping
Authors: LEBLANC Camille , CHAZOT Jean-Daniel , CASTILLO Pedro , MARCHIANO Régis , GRAS Thibaut
Published: October 2024

Acoustic imaging for the monitoring of industrial infrastructures remains a common feature to address numerous issues, such as diagnosing faults in rotating machinery or detecting gas leaks. Simultaneously, autonomous vehicles have emerged as a strong tool to automate various maintenance
and diagnostic tasks, incorporating increasingly diverse sensors, including microphone arrays. The objective of this work is to present a new control strategy for an autonomous vehicle equipped with a microphone array, aimed at mapping its environment completely blindly. The system must be
robust to background noise and to a wide range of sound levels from sources, in order to be effective in an industrial setting. The control strategy proposed in this preliminary work meets these expectations and allows for mapping a large number of sources in a noisy environment, with a wide
range of sources sound levels. Its versatile approach allows adapting the localization algorithm used between MUSIC and constrained-MUSIC depending on the situation and acoustic environment, leveraging the information the robot will have collected during its measurement. Its performances are
evaluated in a simulation study.
On the optical efficiency of collecting scattered radiation or telescopically imaging the measurement area in airborne acoustic pressure evaluations
Authors: HODGES Timothy , KOUKOULAS Triantafillos , ST-GELAIS Raphael , WU Lixue , DOYON-D'AMOUR Francis , STEPHAN Michel
Published: October 2024

Photon correlation is an optical method for calculating acoustic pressures through particle velocity measurements, involving the intersection of two focused Gaussian beams forming an interference fringe pattern. Particles within this measurement region exhibit sinusoidal motion as a
result of a propagating acoustic pressure wave over the fringes, consequently scattering photons. This scattered radiation is then collected and processed to determine the particle velocity and then the acoustic pressure. In order to analyse the efficiency of the optical collection system,
decoupled optical delivery configurations were implemented. In this case, instead of relying on particles moving over static fringes, moving fringes can be made to pass over an apparently static particle. To simulate this effect, a single laser beam can be modulated with a 3-D printed pattern
simulating sinusoidal particle motion across fringes. Having established this alternative delivery system, suitable optical collection systems can be implemented, so that their efficiency can be analysed and assessed. This paper reports on the details of two such collection systems; analysing
spherically propagated radiation and telescopically capturing the measurement area respectively.
Structure-property relationships of polydisperse open-cell foams: Application to melamine foams
Authors: NGUYEN Cong Truc , LI Dengke , XIONG Ziming , HE Mu , GAUTRON Laurent , DUVAL Arnaud , PERROT Camille
Published: October 2024

The melamine foam presents a unique microstructure characterized by an interconnected network of solid struts, which form the edges and faces of high porosity open cells. This study investigates the influence of pore size distribution on acoustic properties for three commercially available
melamine foams. Based on the measured transport parameters, a top-down approach is employed to determine the equivalent Kelvin-cell size corresponding to each transport parameter. The differences found in these equivalent pore sizes indicate that the mono-size model is not suitable for these
materials, a difference from which a quantitative estimate of the level of polydispersity can be deduced (using macro-scale information). The polydispersity was confirmed from experimental evidence at micro-scale from the analysis of SEM images. Moreover, the measurements collected at micro-scale
(average pore size and its standard deviation) can be used as input data to determine the transport and sound absorbing behavior of melamine foam samples from structure-property relationships available for open cell microstructures. This work provides evidence that the polydispersity of melamine
foams should be taken into account to obtain an accurate and consistent picture of microstructure and transport properties of such open cell high porosity foams.
Evaluation of railway noise calculation models using CNOSSOS-EU considering the effect of rail roughness
Authors: WRóTNY Marcin , HALADIN Ivo , BURNAC Kresimir
Published: October 2024

Railway noise assessment is an important tool in decision-making for urban planning, investment in transportation infrastructure and implementation of noise reduction strategies. Currently, the procedure is based on CNOSSOS-EU (Common Noise Assessment Methods in Europe), which was developed
in accordance with European Directive 2002/49/EC. This method takes into account a variety of factors impacting rail noise levels, such as vehicle characteristics and track features. The purpose of this study was to investigate the influence of rail roughness on generated railway noise and
to evaluate the accuracy of calculation models using CNOSSOS-EU. The study involved in-situ railway noise measurements at three different locations near the city of Zagreb, Croatia, and measuring rail roughness at each location. In order to eliminate the influence of other factors, the rail
track structures at the measurement locations were similar, and an identical train configuration was used for the study. Finally, a comparison was made between calculation models based on default roughness values and models including values obtained from in-situ measurements. This approach
enabled an assessment of the variations in CNOSSOS-EU calculation models taking into account actual in-situ rail roughness measurements.
The impact of automobile warm-up noise characteristics on annoyance
Authors: SAKAKIBARA Mika , ISHIMITSU Shunsuke , KISHIKAWA Naoki , FUJIKAWA Satoshi , IWATA Kiyoaki , KIKUCHI Masakazu , MATSUMOTO Mitsunori
Published: October 2024

In the automotive industry, the sound of a vehicle plays a crucial role in its perceived value, highlighting the importance of understanding the relationship between subjective auditory perceptions and objective physical measures. This study investigates the psychoacoustic properties
of warm-up noise emitted by vehicles equipped with an accelerated warm-up system (AWS). Our main goal is to analyze the discomforting aspects of this noise and reveal that its cause is related to tonality. Through extensive auditory experiments, we aim to uncover the nuances of this relationship,
finding that both tonality and roughness significantly contribute to annoyance perception, particularly at higher frequencies. This investigation provides crucial insights for acoustic optimization in automotive systems, focusing on improving the user experience and product quality during
the AWS warm-up phase.
Investigation of sound field diffuseness in an irregularly-shaped room based on FMBEM incidence directivity analysis
Authors: HAGIWARA Ryo , MASUMOTO Takayuki , YASUDA Yosuke , SAKUMA Tetsuya
Published: October 2024

Several methods to evaluate sound field diffuseness have been proposed in terms of the isotropy of traveling sound waves. In a previous paper, we investigated the characteristics of two kinds of diffusion indices in a rectangular room, based on the incidence directivity analysis employing
the FMBEM. The present study applies the incidence directivity analysis to an irregularly-shaped reverberation room for measurement of sound absorption, and investigates the effects of room shapes and absorbing surfaces on the diffusion indices. The numerical results show that the indices
tend to be higher in an irregularly-shaped room than in a rectangular room, and those decline remarkably with increasing the absorption coefficient of the walls. Moreover, the tendencies are more clearly seen in the diffusion indices for the 1/3-octave bands than for single frequencies.
Experimental analysis of wheel and bogie frame transfer functions for on-board measurements of rail roughness
Authors: BURNAC Kresimir , HALADIN Ivo
Published: October 2024

Acceleration measurements on in-service rail vehicles give many valuable insights into track condition. These measurements are favourable in terms of measurement frequency, no need for additional track possession for measurements, operator safety, etc. The collected acceleration data
however needs to be further processed to extract more detailed information on rail surface defects. To derive rail roughness from bogie frame acceleration, a complex signal processing approach is required, as well as determining the dynamic parameters of the track, vehicle, and operational
conditions. In this paper, a method to evaluate the influence of resilient wheel and bogie frame on the acceleration data received from bogie frame-mounted accelerometers is described. The method is based on a standstill measurement of frequency response functions on wheel and bogie frame
positions using an impact hammer and accelerometers. Following the preliminary results of bogie acceleration measurements, in-situ wheel receptance measurements were carried out on the same tramway vehicle in a standstill position, to determine the transfer function between the wheel-rail
contact point and the position of the accelerometer mounted on the wheel frame. After the experimental study, a discussion of their potential application in the method for deriving rail roughness from vibration data is presented.
Preliminary investigation of nanofibrous membranes for sound absorption
Authors: PETTONI POSSENTI Vincenzo , MACCAFERRI Emanuele , FUSARO Gioia , BARBARESI Luca , MAZZOCCHETTI Laura
Published: October 2024

Nanofibrous membranes show interesting mechanical properties, low thickness and lightness, besides the possibility of using a great variety of polymers. The electrospinning technique makes possible the production of polymeric random nanofibres to form nonwoven membranes, which are currently
used in several application fields, such as filtration, biomedicine, biomechanics, electronics, and composite materials. Their application in the automotive and aerospace engineering field could bring significant benefits to the acoustic comfort design. However, their acoustics properties
still need to be further assessed. This study investigates the acoustic absorption of electrospinning-made nanofibrous membranes in Nylon 66 with different fibre diameters and mat thicknesses. Morphological and thermal characterisation of the electrospun membranes have been assessed via Scanning
Electron Microscope (SEM) and Differential Scanning Calorimetry (DSC), respectively. The acoustic absorption characteristics of various samples changing fibre diameter, membrane thickness and mounting conditions were tested in the impedance tube. The results showed more relevant acoustic absorption
properties in the nanofibrous membrane coupled with a polyester fibre. Further studies will clarify if filament direction and constituent material can be improved for a more durable and resistant membrane application.
Empirical method for predicting speech sound propagation in offices
Authors: MACHNER Rainer , KLEIN Achim , BROKMANN Holger , KRUMMHEUER Hannes , DANNER Gerd
Published: October 2024

The room acoustic parameters of ISO 3382-3 allow for an evaluation of sound propagation and speech intelligibility in open-plan offices and have increasingly been used in the planning process since their introduction in 2012. The input parameters are the speech sound pressure levels
and the speech transmission indices at the workstations along a measurement path including a sound source (imaginary speaker). ISO 3382-3 is a measurement standard - a calculation method is not defined. However, it is possible to calculate the necessary input data, namely the speech sound
pressure levels and the speech transmission indices, using room acoustic computer simulations. Although computing power is no longer a limiting factor today, the modeling and verification of computer models are still complex and correspondingly time and cost intensive. Hongisto and Keränen
(2013, 2015) describe a model for predicting the ISO 3382-3 parameters. In this study, this prediction model was tested using measurement data from several open-plan offices in Germany. Recommendations for the application of the model are derived from preliminary investigations, and the limitations
and boundaries of the method are further specified.
How porosity can reduce the sound radiation of electrical coils?
Authors: DAUCHEZ Nicolas , GARCIA Carlos , BENAMAR Amine , LANFRANCHI Vincent
Published: October 2024

High-power electrical coils used in the electricity transmission network can create a noise nuisance for local residents. These industrial coils are made up of a multi-strand cable winding, giving them a cylindrical shell shape. Electromagnetic excitation by Lorentz forces induces coil
vibration, creating an undesirable sound field. In this study, we investigate analytically and by numerical simulation the reduction of acoustic radiation using regularly spaced apertures. As the shell becomes porous (with a porosity of less than 10%), acoustic short-circuits appear. We show
a reduction in radiation efficiency and the impact of apertures on the structure vibration. Our results offer insights into the design and optimization of apertured electrical coils to mitigate noise generation.
Exploring perception and immersive experience of visually impaired people in 360° video and 3D ambisonic audio
Authors: BOUCHERIT Samiha , MASULLO Massimiliano , AUMOND Pierre , CAN Arnaud
Published: October 2024

For a long time, immersive experiences have been designed with primarily sighted users in mind. However, recent advancements open exciting possibilities for expanding this realm to include individuals with visual impairments such as Cataracts, Glaucoma, and Severe low visual. One promising
avenue lies in utilizing 360-degree videos with 3D Ambisonic audio recordings to create immersive experiences specifically tailored to their unique perceptual abilities. In this context, this preliminary study investigates audio-visual perception and presence of visually impaired people (VIP)
in immersive reality (IR) environments, by applying 360-degree video and 3D Ambisonic audio recordings in three different environments of a public park "Parking area, Green space, and Playground". The methodological approach of this study is based on a comparative study between sighted
(SIG) and visually impaired people (VIP), by conducting questionnaires such as the presence questionnaire and the emotional salience questionnaire. The findings show that both categories can experience the same presence within the IR environment with a difference in the evaluation of the acoustic
environment, where the visually impaired show a greater influence on mechanical sounds. By designing inclusive experiences for all, IR has the potential to be equally engaging and immersive for everyone, regardless of sight.
The measurement of tire-road noise: how does standardization contribute to the development of low noise pavements in Europe
Authors: ANFOSSO LEDEE Fabienne , KRIVANEK Vítězslav , STRYK Josef
Published: October 2024

Low-noise road pavements are among the most effective solutions for reducing road traffic noise emission at the source. There was a significant international effort over the past years for developing and standardizing methods for measuring tire-road noise emission, essentially Statistical
Pass-By (SPB) and Close ProXimity (CPX) methods. The dedicated Working Group of the European Committee for Standardization (CEN/TC227/WG5) recently investigated how these standards are used in practice and how they contribute to the implementation of low-noise pavements. For this, a survey
was launched and 14 European countries responded on their practices. The survey showed a large diversity of use, although all refer to the measurement methods SPB, CPX. Based on these methods, some countries have developed national regulations or reference guidelines to specify and assess
the acoustic performance of road surfaces. These procedures are, however, significantly different and lead to varying definitions of low-noise pavements, which prevents sharing knowledge, experience and data. This context justifies the ongoing development within CEN/TC227/WG5 of a standard
procedure for the acoustic characterization of road pavements based on existing measurement methods. The paper will present and analyze the results of the survey, then will present the ongoing work in CEN.
The right fountain for the right place? An in-situ co-creative soundscaping methodology
Authors: VAN RENTERGHEM Timothy
Published: October 2024

Road traffic noise-polluted parks pervade the urban landscape, hindering the enjoyment of the relaxing potential and cognitive benefits that urban parks offer. Soundscape augmentation with natural sounds has demonstrated its merits in this context before, and deliberately introducing
fountains can be an attractive solution since such installations can be easily controlled. This work describes a co-creative in-situ experiment where locals help select the most suited fountain at a predefined design spot during the planning phase, with a clear focus on sound. The simplified
auralization approach, with loudspeakers positioned at the pond's bank, allowed participants to evaluate various fountain scenarios in an ecologically valid context. To arrive at the optimal choice, sound pleasantness and the road traffic noise masking potential of the (combination of) fountain(s)
should be balanced.
Participative pilot study at the vicinity of airports for the construction of a noise point counter integrating instantaneous annoyance at overflight
Authors: MIETLICKI Fanny , MIETLICKI Christophe , SINEAU Matthieu , HELLOT Manuel
Published: October 2024

Current regulations on transport noise are based on energetic acoustic indicators that do not adequately reflect the intensity and repetitive nature of noise peaks, particularly for aircraft overflights or rail traffic. The public debate on these issues therefore often centres on the
questioning of these indicators, which are deemed to be inadequate to reflect the annoyance caused to local populations, particularly in a context of increasing traffic. Bruitparif suggests exploring a noise events counter, the Noise Point Counter (NPC), based on existing NAX indicators but
freeing itself from the threshold effect, which is a drawback to their use. The idea is to count the number of noise events, weighting each event according to the level of instantaneous annoyance it is likely to generate for local residents. To make progress on the feasibility of developing
such an indicator and to confirm its relevance, Bruitparif is proposing to carry out a pilot study on three selected overflown areas in the Île-de-France region, involving around thirty local residents on each occasion. The paper will present the principle behind the creation of this
new indicator as well as the pilot study protocol.
Railway psychoacoustic annoyance - an indicator for planning infrastructure projects
Authors: EGELER Jonas , HUTH Christine , SCHLESINGER Anton , ENDE Christoph , KOCH Thomas , BARTNITZEK Jens , HOEHLE Laura , SCHLUETER Benjamin
Published: October 2024

The joint project "Real-time Calculation, Auralization and Visualization of Sound Propagation and Noise Protection Measures for Infrastructure Projects" (EAV-Infra), funded by the German Federal Ministry for Economic Affairs, investigates the potentials of digital infrastructure
planning based on Building Information Modeling (BIM) in combination with state-of-the art Auralization and Visualization technology as well as Psychoacoustic Modelling. Currently, log-scaled sound pressure levels, which are only informative to experts, are used to communicate the topic of
noise exposure to the public. Auralization, in combination with a hearing-oriented noise index, will constitute a more intuitive and understandable evaluation basis for residents. One focal point of EAV-Infra is the development of a linearly-scaled metric for railway noise, which correlates
better with human perception than the LAeq. Binaural recordings of a wide spectrum of different railway pass-by scenarios were presented in listening experiments to obtain semantic-differential information about the sounds as well as global and continuous annoyance ratings for individual passings.
Currently, a railway psychoacoustic annoyance metric is being developed by comparing two fitting methods: a classical model based on common psychoacoustic quantities, as well as an AI model with a Mel-log-spectrogram-CRNN architecture. The approach and first results will be discussed in this
contribution.
The impact of visitor attributes on the spatial experience in exhibition halls with background music
Authors: JIANG Jiani , MENG Qi
Published: October 2024

The exhibition hall is public architectural space with diverse forms, which serves as an exceptional research environment for investigating spatial experience. As a potent auditory stimulus capable of evoking emotions effectively, music exerts influence on behavioral responses in different
contexts. However, the existing literature on interior space design rarely integrates soundscape considerations. Therefore, this study aims to explore the impact of tourist attributes-such as music learning experience, listening frequency, exhibition visiting motivation, personality traits,
and neuroticism-on spatial experiences based on music perception and interior layouts. The background music is categorized into five sound conditions based on mode and tempo: no music, medium tempo in major, medium tempo in minor, fast tempo in major, and slow tempo in major. Meanwhile, the
exhibition space is classified into four categories according to its interior layout: axis space, scale contrast space, shape contrast space, and flow space. The result shows that in different spatial environment with different music background, tourist attributes have different effects on
the subjective spatial perception.
Observation of the modal propagation of T waves using distributed acoustic sensing
Authors: LECOULANT Jean , PINSON Samuel , PERRON Jean-Michel
Published: October 2024

T waves are low-frequency acoustic-waves (< 100 Hz) generated by earthquakes and propagating in the watercolumn. It is largely accepted that T waves propagate as modes. However, the direct observations of this modal propagation in experimental data remain surprisingly rare. Observation
of T waves using distributed acoustic sensing (DAS) makes possible space-sampling with one sensor every few meters over tens of kilometers. Using a simple 2D Fourier transform, the time-space pressure-field can be turned into a frequency-wavenumber field where the propagating wave dispersion
curves are revealed. Using freely accessible data from a DAS experiment on the coast of Oregon (USA), we show that the dispersion curves of T waves are consistent with the presence of four propagating modes. The number of modes decreases as expected as T waves propagate shoreward with decreasing
depths. The T-wave mode dispersion curves can be fitted by using environmental parameters obtained through ambient noise Scholte wave inversion (also visible in the data).