bluuebunny/crossref_metadata_2025 huggingface dataset:
Multispecies soundscapes: a more-than-human approach
Authors: RUIZ ARANA Usue
Published: October 2024

Sound and listening are integral to how communities engage with environments. Accordingly, many soundscape research projects are currently carried out to improve environments, with methods rapidly developing in a variety of human and non-human-centred fields. Although developments are
taking place in parallel, approaches are yet to be fully integrated for the design and planning of multispecies soundscapes for the health and well-being of all communities. Human and non-human approaches to soundscape research differ not only in the methods used to assess the soundscape (subjective
versus objective) but also in the conceptualisation of soundscapes and the aims of their research. This paper is an exploratory proposition towards the alignment of human and non-human soundscape approaches and aims to instigate questions and further research towards the expansion of soundscape
practices. The paper argues that the planning and design of multispecies soundscapes requires the understanding of different conceptualisations and aims before attempting to integrate methods, and critically reviews incipient approaches and practices that are seeking to bridge subjective and
objective, human and non-human, soundscape research.
Flyover auralization of a blended wing body aircraft considering atmospheric turbulence effects
Authors: PIEREN Reto , LINCKE Dorothea , HEUSSER Axel , LE GRIFFON Ingrid , BERTSCH Lothar , CENTRACCHIO Francesco , WEINTRAUB Daniel , LAVANDIER Catherine , SCHäFFER Beat
Published: October 2024

In the ARTEM project a novel blended wing body (BWB) long-range aircraft was designed and optimized for low-noise operation. Virtual flyovers of different BWB vehicle variants were synthesized and auralized in the AuraLab using a loudspeaker array. Prior to auralizing the novel aircraft,
the applied methods were hierarchically validated by comparison with field recordings of existing jet aircraft, assessing acoustical indices, time-frequency features, perceived plausibility, and induced noise annoyance. To achieve convincing syntheses, the focus was on developing new auralization
models for a realistic representation of atmospheric turbulence effects. The syntheses of the BWB obtained with the successfully validated methods were then used in psychoacoustic laboratory experiments for perception-based evaluation regarding (minimized) noise annoyance. The evaluation revealed
that, while the BWB may initially be perceived as somewhat more unfamiliar, it is substantially less annoying than current tube-and-wing long-range aircraft of similar range and mission for take-offs as well as for landings.
Anthropogenic noise and impact on marine species : Acoustic metamaterials as a reduction solution
Authors: KESSLER Juliette , CROËNNE Charles , POUILLE-FAVRE Monique , DROUET Céline , HLADKY-HENNION Anne-Christine
Published: October 2024

Anthropogenic underwater noise generated by offshore maritime activities poses a significant threat to nearby ecosystems due to elevated sound levels. Efforts have to be undertaken on noise reduction solutions, depending both on the offshore activities and on the marine species. In
this context, leveraging the recent advances in underwater acoustic metamaterials seems crucial, due to their special properties in terms of scattering and absorption. This endeavor aligns with advancing Marine Renewable Energies while minimizing environmental impact. In this communication,
a synthetic review is first proposed to define the various maritime works targeted, as well as their associated sound levels and frequency ranges of emission. In a second part, a cartography is outlined by classifying different marine species according to their hearing type, depth of immersion
and auditory threshold. Then, in relation with the two previous analyses, solutions based on metamaterials for deep sea immersions are proposed. In particular, a multi-periodic arrangement of bars is proposed that exhibits several band gaps (i.e. frequency ranges in which propagation is forbidden),
in order to limit the transmission of sound waves in a large frequency range. The concept can be easily extended depending on the targeted offshore activities and marine species.
Coupling deflectometry measurements on membranes to the force analysis technique: opportunities and challenges
Authors: MOUGEY Anaïs , FOUCARD Félix , MELON Manuel , ROBIN Olivier
Published: October 2024

This work is grounded on the force analysis technique, an identification method that directly uses a structure's equation of motion to formulate an inverse problem, explicitly identifying the force causing the system's motion. This technique has mainly been applied on heavy objects
since contact vibration measurements using accelerometers on light and thin structures are biased by the added mass and are complex to setup. Using non-contact and full-field vibration measurements (here, deflectometry), opens the possibility of applying the force analysis technique to such
structures. This research aims to investigate the opportunities offered by the identification of space-time varying loadings of various types (acoustical, mechanical, and turbulent boundary layer) all these loadings being applied on a membrane. Through this study, we also strive to highlight
the challenges and opportunities brought by of coupling non-contact and full-field measurements on membranes to the force analysis technique.
Development of vibration isolation system for halls and report on sound insulation and vibration experiment
Authors: NAKAKITA Tao , FUJITA Etsushi , ENOMOTO Yuji , KANETA Keita
Published: October 2024

Rubber and polyurethane have been widely used as vibration isolation materials in halls and studios. In this project, we have developed a floor-mounted coil spring vibration isolator with improved vibration isolation and sound insulation characteristics, while keeping the installation
height equivalent or lower than rubber and polyurethane. In this paper, we evaluate the vibration isolation performance of the developed device by measuring vibration transmission loss, and confirm that the device can suppress surging, which is a weak point of metal springs, while achieving
a low natural frequency. The sound transmission loss measurement also confirmed that the floating slab incorporating the device has sufficient sound insulation performance, and these results indicate that the device can be applied to acoustic spaces such as concert halls, where quietness is
required.
Indiscernible noise determination of a military system equipped with an internal combustion engine
Authors: BILICAN DOĞUKAN , SEN OSMAN TAHA
Published: October 2024

The main objective of this paper is to explore the non-detectability criteria of military systems and to determine the indiscernible noise of military systems equipped with internal combustion engines. Non-detectability is one of the critical requirements evaluated for military defense
systems and it is defined strictly in MIL-STD-1474E standard. Furthermore, this standard specifies the limits of sound pressure levels conservatively for 1/3 octave bands. Though, the standard does not define indiscernible or inaudible noise levels for events in the presence of background
noise. It is also not explicitly well-defined in the existing literature. This study presents a comparison of non-detectability distance defined in MIL-STD-1474E standard and indiscernible noise of a military system extracted from the measured octave band sound levels, which are processed
based on sound propagation theory. In this study, several parameters such as atmospheric absorption, geometric spreading, ground effect, terrain type, obstacle existence are included to determine the indiscernible noise level of the military system of interest. The results are compared with
the non-detectability distance limits given in the MIL-STD-1474E standard, and it is observed that the proposed method of indiscernible noise, which is defined as extracted sound level should be lower than the background noise, is well-correlated.
Characterization of adhesion within structural materials by means of guided elastic waves
Authors: GIRARDOT Loïc , BENTAHAR Mourad , MONTRéSOR Silvio , TERRIEN Nicolas
Published: October 2024

Assembly methods in industry have improved considerably during last decades and mechanical fastening is increasingly abandoned in favor of structural bonding and/or welding methods. The need for improved nondestructive testing and evaluation (NDT&E) methods becomes therefore important
particularly for thermoplastic composites welding. Indeed, the latter welding process generates subtle defects (Kissing Bonds) that can hardly be detected, hence the need to develop specific well-calibrated techniques. In addition to bonding testing which is based on the existing contrast
between high and weak bonded areas, it remains necessary to determine the adhesion quality, particularly in the case of multi-layered materials. In this contribution a nondestructive quantification method of the adhesion strength corresponding to welded assemblies is presented. The work is
based on the use of an ultrasonic contactless experimental device based on air-coupled ultrasound propagating within welded composites. The work takes advantage of the existing interaction between the generated guided waves and the composite structure along the propagating distance in order
to locate defects and evaluate the adhesion of the tested thermoplastic welded assemblies. This rely on the basis of an inverse method based on the dispersion curves of Lamb waves, which revealed to be sensitive to the deterioration in adhesion quality.
Acoustic evaluation: microphone array measurements on a multi-megawatt individual pitch control wind turbine
Authors: SHARMA Ashutosh , KRAASCH Corinna , WEGNER Anna
Published: October 2024

As rotor diameters of wind turbines approach 200 m, aerodynamic noise becomes a significant issue, especially for onshore turbines. The rapid expansion of wind energy has led to increased concerns regarding the noise generated by wind turbines particularly in proximity to residential
areas. This study investigates the noise emissions from a full-scale multi-megawatt individual pitch control (IPC) onshore wind turbine, with rotor diameter of 158 m and a hub height of 120 m, across 12 scenarios-six upstream and six downstream. The wind turbine under investigation operates
under both IPC and non-IPC modes. Utilizing a microphone array and beamforming algorithm techniques, we conducted comprehensive acoustic measurements to analyses the noise sources and their characteristics. Our findings indicate that turbine operating in IPC mode produces higher sound pressure
levels dB (A-weighted) as compared to the turbine under non-IPC modes. This observation emphasizes the need for a balanced approach in wind turbine operations, considering both load reduction and noise mitigation.
Creative use of soundscape/smellscape protocols for integrated spatial understandings
Authors: XIAO Jieling , ALETTA Francesco , LINDBORG Per Magnus
Published: October 2024

This paper reviews an experimental workshop exploring creative ways to use soundscape and smellscape protocols for better spatial understandings. It aims to find out how visual methods such as drawing and making could contribute to the recall process. The reflections of the experimental
work address the challenge of gaining integrated spatial information of the sonic and olfactory environments through the current approach based on protocols (e.g. psychoacoustic parameters such as eventful-monotonous, vibrant-chaotic, etc.) and interviews. The protocol is found useful to get
an abstract impression of the overall soundscape and smellscape with sound and smell marks. Sound memories are found less object-related whilst smell memories are expressed less in sketches. The discussion suggests a more structured narrative approach will be useful when integrating such artistic
methods for spatial details. The sketching and objects making task stimulates crossmodal recall of auditory and olfactory memories.
A deep learning approach to predicting UAV sound affect
Authors: GREEN Marc , TORIJA MARTINEZ Antonio
Published: October 2024

The most prevalent method by which the impact of an acoustic environment upon people is assessed is the `environmental noise' approach, in which the sounds are quantified based entirely on their recorded weighted sound pressure levels. This does not account, however, for the character
of sounds outside of their loudness. Objective metrics such as psychoacoustic annoyance have been developed to attempt to rectify this, however this is still heavily weighted towards loudness as the most important factor and may not provide a good estimate for subjective perceived annoyance
for all sound sources, including unconventional aircraft such as unmanned aerial vehicles (UAVs). Here we present a novel method using a convolutional neural network (CNN) to predict perceived annoyance directly from mel-spectrograms derived from recorded audio featuring both traditional and
unconventional aircraft sources. The network is trained and tested using data collated from five separate listening tests, and is shown to outperform conventional regression models based on psychoacoustic annoyance as a predictor of perceived annoyance. The time-frequency resolution of the
calculated mel-spectrograms is shown to be a key factor in performance.
Exposure of employees to very high frequencies: laboratory measurements
Authors: TERROIR Jonathan
Published: October 2024

Many occupational sectors are subject to noise exposure to very high audible frequencies (VHF) or low frequency ultrasound (LFUS): welding, food cutting, cleaning, etc. Although studies on employee exposure to these sound sources have been carried out since the 1960s, the question of
the location of the measuring microphone and the representativeness of the measurement remains. As part of a study focusing on the risks associated with exposure to VHF/LFUS, the INRS conducted laboratory experiments on a mannequin to assess the variability of exposure measurements under controlled
conditions as a function of microphone location (shoulder, ear entrance, etc.), source frequency and source position in azimuth. Of particular interest was the appropriateness of positioning the microphone at temple level via a dedicated mounting system suitable for use in the field. The findings
of this preliminary work will be used to develop a protocol for measuring VHF/LFUS exposure in situ.
An innovative approach for enclosure design of power generators to meet noise regulation targets
Authors: MISKIN Atul , REDDY Veda Vamsi , HIMAKUNTLA Uma Mahes
Published: October 2024

The use of diesel-powered engine generators as a power source is very common for various industrial and residential applications. There are strict regulatory requirements and legislations to limit the noise levels from these generators below statutory limits. The purpose of the paper
is to present an approach using statistical energy analysis (SEA) augmented by experimental inputs for the prediction of noise levels for the generators and propose strategies for optimized enclosure design that effectively mitigate noise to achieve regulatory requirements. The study begins
by developing an SEA model that represents the acoustic behavior of the generator and enclosure. The airborne sources such as engine, alternator, radiator fan and exhaust are modelled explicitly using experimental noise source characterization. Based on the established SEA model and excitation
sources, noise levels are predicted through the calculation of energy flow between subsystems. The predicted sound levels for an existing Diesel Generator with enclosure were validated with its test data to ensure correctness of SEA model. Parametric studies were carried out using simulations
on key variables, including critical noise paths, panel thickness, and noise control treatments. These investigations helped identify optimal process parameters that reduce noise levels emitted by genset in adherence to noise regulations.
Vibration analysis of functionally graded saturated porous beams using radiative energy transfer method
Authors: XING Yitao
Published: October 2024

An energy flow model based on the radiative energy transfer method (RETM) is established for the high-frequency response prediction of finite functionally graded saturated porous beams. The Timoshenko beam theory and the Biot thoery are applied to derive the motion governing equations
of the beam. The response of the beam loaded by a high-frequency point force is described by vibrational energy density and intensity. The energy response of the beam is contributed by the rays emitted from the actual source set at load point and then reflected through the fictitious sources
at the boundaries. Fictitious sources are determined by the energy balance equations at the boundaries. Numerical examples show that the energy distributions of the saturated porous beams are well predicted by the proposed approach.
An efficient predicting approach for blade frequency line-spectrum noise of marine centrifugal pumps
Authors: LIU Chen , ZHONG Jize , HAN Wang , WANG Yaji , CAO Yipeng , ZHU Longhao
Published: October 2024

The paper introduces an innovative and efficient calculation method for the spectral flow noise of the pump system based on the spatial distribution dipole, which predicts the blade frequency radiation noise at the pipe flange of the pump system under different operating conditions.
First, the unsteady flow simulation of the centrifugal pump is calculated using computational fluid dynamics (CFD). Then, the pressure on each segmented blade surface is decomposed into lift and drag forces. After that, each segment is decomposed into several dipole point sources based on
the blade noise theory. Finally, the simplified dipole point sources are considered sound sources, and the blade frequency line spectrum noise at the pipe flange of the pump system is predicted using acoustic-structure coupling. The results indicate that the simplified method provides high
prediction accuracy while significantly improving the computational efficiency of blade frequency line spectrum noise calculation for centrifugal pumps.
Impact of traffic simulation parameters on the estimation of noise exposure in an urban environment
Authors: MONTENEGRO Alexandra Lyselott , MATTEO Bolognese , PANCI Andrea , PALAZZUOLI Diego , CERCHIAI Mauro , LICITRA Gaetano
Published: October 2024

Since road traffic is the most impactful noise source in the European cities, the evaluation of citizens' exposure is crucial. Although the noise map accuracy is affected by uncertainties in traffic volume, to perform extensive traffic monitoring is not practical and expensive, even
in small cities. Traffic simulation software uses routing algorithms to suggest the fastest path to distribute vehicles from an origin through a network to a desired destination which interacts within the urban environment. Therefore, it could represent an important tool for noise mapping
in the critical task to fill the data gaps in traffic volumes, also for implementing action plans using a suitable traffic management approach. However, there is a lack of evidence on how the choice of traffic simulation parameters influences noise estimation. In this work, we design a simulation
framework to evaluate the impact of routing algorithms on the estimation of population noise exposure in an urban area. Using an open-source pipeline based on public databases and open-source software SUMO and NoiseModelling, we evaluated the implication on the traffic distribution and resulting
noise exposure for a set of traffic model key parameters.
Feedback from acoustic and vibration mitigation measures on buildings along railways
Authors: GUIGOU CARTER Catherine , MAILLARD Julien , DUCRUET Pascal , ROPARS Pierre
Published: October 2024

Designing buildings very close to existing railway track with heavy commuting traffic requires special attention regarding noise and vibration. The situation reported in this paper is that of an existing embanked railway line 20 km East of Paris, where buildings have been constructed
right above the embankment and not too far from a station. Consequently, as the tracks cannot be modified, the mitigation measures have been taken on the receiver side, i.e. the buildings. The noise and vibration mitigation measures implemented in buildings in order to limit occupant annoyance
are first described. Then, acoustic and vibration measurements inside and outside of the considered buildings are discussed and results examined with respect to the implemented mitigation solutions. Finally, measured vibration and sound levels are compared to target values under discussion
for new regulation on ground borne-noise and vibration levels in buildings along railways.
Simplified modeling of elastic guided waves in a pre-stressed cable
Authors: KONDYLIDIS Konstantinos , IRIE Bi djaha Roméo , TREYSSèDE Fabien , LAGUERRE Laurent , MORA Pierric
Published: October 2024

Elastic waves can be employed to probe the mechanical state of pre-stressed cables and look for defects in critical areas. Contacts between wires have been shown to play a major role in wave propagation by giving rise to tension-dependent phenomena such as anomalous transmission at
certain frequencies (the "notch frequency effect"). Here, we present a simplified way of modeling the free propagation of waves at low frequencies by analytically accounting for contacts. Wires are described within beam theory and connected with tension-dependent springs derived
from Hertz law. In contrast to point-wise contacts, these line-wise contacts also induce second-neighbor coupling, i.e. they connect wires that are not in direct contact one another. The simplified model is compared with a reference model based on a finite elements representation of the cross
section ("SAFE" method). The range of validity in frequency is discussed. The results provide a new interpretation for the first higher order modes in and their dependence with tension in terms of contact resonances. The drastic reduction of numerical costs suggests the method could
be applicable to more complex civil engineering cables, composed of many wires.
The effect of combined exposure to noise and vibrations from rail traffic on sleep: results from the follow-up study "Living in the vicinity of the railway"
Authors: VAN KEMPEN Elise , HOEKSTRA Jurriaan , SIMON Sendrick , VAN WIJNEN Harm , KOK Arnaud , VAN KAMP Irene
Published: October 2024

As a result of policy aims to improve accessibility and achieve climate targets, an increase in rail traffic is foreseen for a while. It is therefore expected that in the future more problems will arise due to the vibrations and noise that trains produce. It is demonstrated that most
problems are caused by freight trains, predominantly tracking during the night, hence affecting sleep. Research has shown that both noise and vibrations from rail traffic can affect sleep; evidence on the impact of combined exposures is scarce. To investigate the effect of combined exposure
to noise and vibrations from rail traffic on self-reported sleep disturbance, we used data from a survey aimed to investigate people's reactions on railway vibrations. In 2021, 17,189 people of 16 years and older, living within 300 meters of a railway track in The Netherlands were invited
to fill in a questionnaire. Exposure to vibration and noise levels from rail traffic during the night were modelled and linked to the addresses of the 5,611 (33%) participants. We used logistic regression models to test the associations between rail traffic vibration or noise exposure and
sleep disturbance for different noise and vibration exposure groups. This paper presents preliminary results.
Computation of Green's functions for the acoustic scattering by an elastic structure excited by a turbulent flow in water
Authors: PACAUT Louise , MERCIER Jean-François , CHAILLAT Stéphanie , SERRE Gilles , COTTé Benjamin
Published: October 2024

To model the hydrodynamic noise produced by an elastic ship hull or propeller excited by a turbulent boundary layer, we need an efficient method to compute the acoustic scattering by an elastic body surrounded by a fluid. In 3D, Boundary Element Methods (BEM) are used to reduce the
computational costs, for both the fluid and the elastic body. A natural way to compute the boundary integral representation (BIR) of the sound pressure is to use formulations based on the free space acoustic and elastic Green's functions. However, since the turbulent flow along the elastic
body is known only statistically, the use of these Green's functions would be too expensive. A remedy is to compute a Green's function adapted to the physical problem, thus satisfying the transmission conditions of the fluid-structure problem. This so-called "tailored Green's function"
is determined by solving a coupled acoustic-elastic problem with the BEM, and leads to a simplified BIR of the sound pressure compatible with a stochastic source term. We first validate the computation of the tailored Green's function over a classic spherical geometry. Then we compare the
scattering of multiple quadrupoles by elastic or rigid NACA0012 profiles.
Noise and inflow velocity measurements of fixed pitch rotors in edgewise flight
Authors: UKEILEY Lawrence , GOLDSCHMIDT James
Published: October 2024

A common design of many of the proposed generation of electric Vertical Takeoff and Landing (eVTOL) vehicles involves fixed pitch rotors in edgewise flight. These applications typically have significantly lower tip Mach numbers than conventional rotor-craft and involve distributed smaller
rotors making them operate at lower Reynolds numbers and hence likely having a greater sensitivity to gusts and environmental turbulence. This work will present results of studies with fixed pitch rotors conducted in the UF Anechoic Wind Tunnel Facility. The studies involve radiated noise,
thrust and stereoscopic Particle Image Velocimetry to measure the inflow velocity to the rotor plane. The measurements were taken for un-altered free stream conditions as well as ones subjected to three different turbulence generation grids. The results provided show that there can be effects
at moderate levels of free stream to turbulence to the rotor efficiency and radiated noise.
Cross-comparison of the optical and acoustical calibration methods for microphones based on microelectromechanical system technologies
Authors: KOUKOULAS Triantafillos , CHO Wan-Ho , SABA Fabio , PAESANTE Davide , SCHIAVI Alessandro , DURANDO Giovanni , PRATO Andrea , WU Lixue
Published: October 2024

Calibration methods and associated international standards in airborne acoustics have enabled national metrology institutes to establish and maintain a fully defined traceability chain for designated laboratories and end users of microphones. However, such microphones need to be reciprocal,
of condenser type and of specific dimensions; this, in effect, does not allow for the calibration of alternative existing sensor technologies and creates a further obstacle for the calibration of emerging technologies. An example relates to microphones based on microelectromechanical systems
which are an integral part of a wide range of electronic devices; yet, there is no established calibration traceability chain other than methods employed by manufacturers. From a metrological perspective, new calibration methods that can accommodate microphones regardless of their size, reciprocal
nature and utilised technology must be developed and subsequently standardised and adopted. This paper discusses the optical calibration method based on free field photon correlation and the acoustical calibration methods based on pressure comparison and free field substitution. These approaches
can provide traceability to the international measurement standard system for novel types of microphones, and the measurement results showed themselves to be consistent. Based on this study, the possibility of expanding the new standard system was investigated.
How does visual context of urban open spaces drive soundscape pleasantness and eventfulness: a laboratory experiment using a higher order Ambisonics speaker system and immersive virtual reality
Authors: TIN Oberman , MITCHELL Andrew , ALETTA Francesco , KANG Jian
Published: October 2024

Perception of sound environments is influenced by the context we experience them in. A big portion of the contextual information comes from the visual domain, including our understanding of what a place is but also from its visual features. A laboratory study combining questionnaire
responses and eye-tracking tools was designed to investigate if the soundscape outcomes and participants' behaviour inside the simulation can be explained by the perceptual outcomes defined by visual information. 360 degree videos and First Order Ambisonics audio recordings of 27 different
urban open spaces taken from the International Soundscape Database were used as the stimuli delivered via a Virtual Reality Head-Mounted Display and a Higher Order Ambisonics speaker array, while a neutral grey environment without sounds being reproduced represented the baseline scenario.
A questionnaire tool was deployed within the IVR simulation to collect participants' responses describing their perception of the reproduced environments corresponding to the circumplex model featured in the Method A of the ISO/TS 12913-2. The results revealed a good coverage of the two-dimensional
perceptual circumplex space and significant differences between perceptual outcomes driven by sound and those driven by visual stimuli.
HRTF individualization using ear images from 3D meshes
Authors: ALVAREZ-MARTíNEZ Ariel , LóPEZ MONFORT José Javier
Published: October 2024

The head-related transfer function (HRTF) describes how a human receives sound from different directions in space. It is unique to each listener. The best way to obtain an individualized HRTF is through direct measurement, but it requires sophisticated laboratory equipment and long
measurement times. This work proposes an approach for HRTF individualization employing ear images from 3D meshes using a deep neural network and spherical harmonics transform (SHT). The method relies on the HUTUBS dataset, including 3D meshes and HRTFs. The model uses ear images to predict
a low-dimensional representation of the HRTF. Initially, ten images of the right ear of each 3D mesh are taken in different positions. The model consists of two main parts. The first is a convolutional neural network (CNN), which is used to extract features from the ear images. The second
part learns from the feature map obtained and predict the spherical harmonic coefficients. Finally, the individualized HRTF is obtained through inverse SHT. The performance of the method is evaluated by computing the log-spectral distortion (LSD) between the measured HRTF and the predicted
one. The results show favorable LSD values compared to other models addressing the same problem.
Increasing measurement accuracy by estimating multiple dissipations for the impedance tube calibration
Authors: CHEN Ziqi , XIANG Ning
Published: October 2024

Impedance tube measurements, employing transfer function/matrix methods, are commonly used by acousticians to characterize the acoustic properties of materials in normal incident conditions. Sound dissipation in impedance tubes can impact the accuracy of measurement results. Various
effects contributing to sound dissipation in tubes are studied and analyzed. This research investigates different dissipative effects and dissipation models. This paper uses model-based Bayesian inference to estimate critical parameters in multiple dissipations. The experiments involve using
an empty impedance tube terminated with a rigid metal block. A hypothetical air layer in front of the metal block is assumed for establishing a prediction model in contrasting estimation results with theoretical values. The results incorporating dissipation models demonstrate a good match
with the theoretical calculation of the air layer. Applying the estimated dissipations to actual resonator materials demonstrates a significantly improves measurement accuracy.
The consideration of a simplified method for predicting aircraft noise
Authors: HANAKA Kazuyuki , SHINOHARA Naoaki , NAKAZAWA Toshiyasu , TAKAHASHI Kouji
Published: October 2024

The Japanese segment model focuses on understanding noise impacts in the surrounding areas relatively close to the airport. The basic data to be prepared for predicting are usually the results of measurements and analysis in the area near the airport. In areas farther away from airports,
the altitude of aircraft is higher, there is an issue that prediction results based on the basic data collected near airports accurately reflect the reality. Often, areas far from airports get complaints even if noise exposure was not high. There is a desire for a model that can predict with
relatively high accuracy and ease even in locations far from airports like this. Based on this background, we have developed a simple prediction model based on actual observation results of noise and flight paths, which can be used as basic data for aircraft noise prediction. In this approach,
a database is created using noise measurements obtained from unattended noise monitoring and short-term survey results and aircraft position information from the ADSB. In noise propagation calculations, predictions are made considering factors such as lateral attenuation of ground surfaces,
air absorption, and variability in flight paths by a simple method.
Road traffic noise assessment method for Hong Kong and associated GIS-based assessment tools
Authors: LEE Chee Kwan , KWOK Kwun Ting Chris , MAK Ho Kun Vince , LEE Chun Hei Jeffrey , LEE Chee Kwan , KWOK Kwun Ting Chris , MAK Ho Kun Vince , LEE Chun Hei Jeffrey
Published: October 2024

Hong Kong, known for its compact and complex urban environment, has long faced unique challenges in modeling road traffic noise for planning and assessment purposes. The Environmental Protection Department (EPD) of the Hong Kong Special Administrative Region Government (HKSARG) identified
and established an enhanced prediction methodology called Road Traffic Noise Assessment Method - Hong Kong (RONOSS-HK). RONOSS-HK aims to provide better treatment on source geometry, source terms, noise propagation, considerations for new-energy vehicles and special noise reduction of the
Innovative Noise Mitigation Designs (INMD) to cater for the complicated spatial noise situations in Hong Kong. To facilitate the implementation of RONOSS-HK, the EPD has also developed and introduced a GIS-based assessment tool which allows users to utilize GIS data readily available in HKSARG
databases and other spatial information in the public domain for accurate road traffic noise prediction using RONOSS-HK methodology. Additionally, the EPD is in the process of further developing a web-based 3D software to serve as an alternative comprehensive assessment tool for applying RONOSS-HK
in noise assessment. This paper introduces RONOSS-HK prediction methodology and the latest development of its associated GIS-based assessment tools.
Railway noise monitoring - a tool to analyse in detail the evolution of noise over time during a rolling stock renewal period
Authors: ROSIN Christophe , REGAIRAZ Jean-Philippe , CORDOLIANI Théo , SINEAU Matthieu
Published: October 2024

As part of the commissioning of a rail freight project, a noise monitoring system was set up to track the increase in rail freight traffic and to monitor noise over time. Noise monitoring is done by continuous measurement stations, an analysis of the classic noise exposure indexes LAeq,6-22h
and LAeq,22-6h is realized, completed by an analysis of several event acoustic indexes, with a distinction between the different traffic types (Freight, regional trains). In addition, the European Regulation EU 2019/774 on the application of the technical specification for interoperability
relating to the subsystem 'rolling stock - noise' to the existing freight wagons, obliges the circulation of less noisy freight trains on certain itineraries called "Quieter routes" from 8/12/2024. The projected benefit will not be limited to the nearby residents of these routes
but will, by indirect consequence, enable a gradual acoustic gain on all the French rail freight routes, due to the retrofit or renewal of the existing rolling stock. The goal of the noise monitoring system is also to quantify the acoustic gains from the indirect effects of this new regulation.
Sound insulation analysis of sound insulation materials laminated with membrane vibration type acoustic metamaterial
Authors: KUROSAWA Yoshio , FUKUI Kazuki , HARAYAMA Kazuya , EBARA Hironori
Published: October 2024

In recent years, research on various acoustic metamaterials has progressed. We fabricated PP into a honeycomb structure and pasted films on the top and bottom to create an acoustic metamaterial that has a sound-absorbing effect due to membrane vibration. Furthermore, a small hole was
made in the center of the film part to add sound absorption effect through Helmholtz resonance. Considering its application to automobile trim, felt and rubber layers were added and laminated on a steel plate. This structure was modeled using the finite element method and the transmission
loss was calculated. We will report on comparisons with measurement results and calculation results for various lamination patterns.
Integrating Mixup and ArcFace for enhanced anomalous sound detection
Authors: CHOI Jihoon , CHOI Jung-Woo
Published: October 2024

In machine condition monitoring, accurate detection of anomalous sounds is essential for timely maintenance interventions. Traditional deep neural network models employ classification-based self-supervised learning to discriminate normal and abnormal operational sounds using classification
confidence. However, these models often suffer from overfitting or excessive confidence, limiting their effectiveness. To overcome this, we introduce a hybrid technique that combines the strengths of Mixup and ArcFace techniques. Mixup enhances model generalization by training on mixed sound
data, while ArcFace promotes greater inter-class distances with an angular margin loss. However, there is a challenge in combining these methods because the angular margin for ArcFace is defined for a single target class, and hence, can be hardly defined for the mixed data utilized in Mixup.
The proposed technique employs the class-dependent angular margins based on the mixing ratio of data. SoftMax losses for individual classes are constructed using the class-dependent margins and then integrated into the Mixup loss. When applied to the DCASE2020 Task2 dataset, the proposed method
significantly outperforms the state-of-the-art NoisyArcMix model in anomaly detection. This approach demonstrates the potential of leveraging class-dependent angular margins in mixed data for improved performance in machine condition monitoring.
Centrifugal pump impeller wheel inspired acoustic metamaterial for low frequency sound absorption
Authors: GOLAKOTI PAVAN , SNEHA Singh
Published: October 2024

Addressing low-frequency noise is a significant concern within the realm of acoustics and noise management. Labyrinthine channel based acoustic metamaterials have been proved to control low frequency noise using local resonance effect and thermoviscous dissipations. Drawing inspiration
from centrifugal pump impeller wheel, an acoustic metamaterial absorber has been devised. The design incorporates impeller vanes to create a channel with variable widths and a micro-perforate panel through which sound wave propagates to the channels. Numerical simulations using COMSOL Multiphysics
and experimental analysis are conducted employing Two microphone impedance tube method. Acoustic pressure and acoustic particle velocity distribution plots from numerical simulation study are used to comprehend the sound absorption mechanism. Sound absorption coefficient results reveal that
this design offers a tunable sound absorption peak in low frequency regime. Furthermore, this paper discusses the influence of various geometric parameters such as, number of vanes, panel thickness and micro-hole diameter. The subwavelength dimensions of the design contribute to noise control
in machineries with space constraints.
Accuracy of fish-eye camera device for aircraft positioning based on laboratory experiment combining computer graphic and 3D Projection
Authors: YAMAMOTO Ippei , MORI Junichi , TSUCHIYA Takenobu
Published: October 2024

For the management of airborne mobility devices such as airplanes and UAVs, such as noise assessment, it is important to measure the three-dimensional position of the aircraft, and various technologies have been researched and developed. We have developed an Aircraft Positioning Camera
(APC) based on an IoT device equipped with a fisheye camera that can mechanically measure aircraft position at a local area with low cost and with high mobility. The performance of this APC is still uncertain as to the limits of the flight altitude and speed of the aircraft that can be measured.
Therefore, a detailed study of its performance is needed. Since, it is difficult to standardize the conditions such as weather and ground surface conditions, it is effective to conduct these studies in a laboratory where environmental changes can be controlled. The performance of this APC
was examined at an experimental facility where images captured by a 360-degree camera or computer graphics can be projected in three dimensions onto a hemispherical dome.
Road traffic noise prediction model "ASJ RTN-Model 2023" proposed by the Acoustical Society of Japan - Part 2: Structure-borne noise of viaducts
Authors: ITIKI Tomoyuki , FUKUSHIMA Akinori , OKADA Yasuaki , ITOHATA Hiroshi , IKEYA Kimikazu
Published: October 2024

The latest road traffic noise prediction model "ASJ RTN-Model 2023" was published by the Research Committee on Road Traffic Noise of the Acoustical Society of Japan (ASJ) in this April. In this new version, the method for predicting structure-borne noise from viaducts was
also updated. Specifically, the calculation method was updated to separate direct sound and ground-reflected sound, and the sound power levels on structure-borne noise from viaducts have revised accordingly based on the latest research results. This paper describes the method for measuring
structure-borne noise, the latest values of noise emission and its frequency characteristics, and the method for predicting structure-borne noise.
Noise information in sales literature of machinery as a support to Sell and Buy Quiet
Authors: HEISTERKAMP Fabian , HOLMBERG Kjell , VAN DER HULST Daan , JACQUES Jean , SáNCHEZ-GUARDAMINO ELORRIAGA Rafael
Published: October 2024

The Sell & Buy Quiet concept helps employers to protect their workers from risks arising from the exposure to noise emitted by machines. Reliable noise emission data are key to successfully implement this concept in practice. The NOMAD (NOise MAchinery Directive) project aims to
assess and improve the quality of noise information provided by machinery manufacturers in sales literature and instruction manuals of machinery in accordance with the Machinery Directive 2006/42/EC. Here, we present the results of a pre-market surveillance exercise, which examined the compliance
of noise information in sales literature. Machinery manufacturers have to provide this information in compliance with the European Machinery Directive, if the sales literature contains the performance characteristics of the machine. The study investigated 85 samples of sales literature and
45 instruction manuals collected in five EU Member States. The faults found in sales literature were similar to those identified in the original NOMAD survey (NOMAD Phase 1), including the absence of noise information, confusion between noise emission and noise exposure quantities, incorrect
notations and terminology, as well as missing noise emission quantities required by the Machinery Directive. Based on our findings, we make recommendations to stakeholders to improve the situation.
Data assimilation for noise mapping using CNOSSOS - A Danish Case Study
Authors: KHAN Jibran , AUMOND Pierre , CAN Arnaud
Published: October 2024

Noise maps play a significant role in developing noise mitigation policies. However, maps based on noise simulation models are likely to be uncertain due to underlying model uncertainties and parameterization. This research work explores the feasibility of data assimilation techniques
to address this issue. A noise measurement campaign was carried out at two locations in the Central Jutland Region of Denmark. Consequently, 76 days (1 September-15 November 2019) (N = 1824 hours) of measured hourly A-weighted, energy equivalent, sound pressure level data (LAeq1h in dBA) was
available for this case study. In addition, traffic counting data was available. The LAeq1h (dBA) levels were then simulated using the EU noise prediction standard, CNOSSOS. The comparison of daily averaged measured and simulated noise levels reveals the Root Mean Squared Error (RMSE) in the
range of 1.4 - 2.8 dBA. Subsequently, data assimilation techniques, such as the Best Linear Unbiased Estimator (BLUE) and Bayesian Inverse Inference, are used to produce improved, hourly, so-called analysis maps with the minimum error covariance. The oral presentation and short article will
present details of model inputs and simulations, data assimilation as well as the strengths and limitations of this research.
Computation of the sound transmission loss of heterogeneous periodic structure using the wave finite element-based methodology
Authors: CUI Dongze , ICHCHOU Mohamed , ATALLA Noureddine , ZINE Abdel-Malek
Published: October 2024

In the present study, a Wave Finite Element-based method is introduced to estimate the Sound Transmission Loss (STL) of periodic structures with contrasting properties. This method addresses the precision and computational speed limitations of existing methodologies. It calculates the
wave STL by applying a plane wave excitation from the ambient medium to a Unit Cell (UC), which is representative of the periodic structure. The STL under Diffuse Acoustic Field (DAF) is then computed by integrating the wave STL over all possible incidence angle ranges. The advantages of this
methodology are demonstrated through various configurations, ranging from simple plates to complex laminated structures. Additionally, the study investigates the Mass Law of STL.
Comparative analysis of CNN and TNN models in environmental noise source identification
Authors: TOPALOVIć Antonio , ZUPANčIč Metod , BOVHA Jure , DOLENC Luka , KING Thomas
Published: October 2024

This paper presents a focused examination of environmental noise, an issue of relevance due to its implications for human health and well-being, compliant with ISO 1996-2:2017 standards. Moving beyond the traditional methodologies that primarily rely on level exceedance, our study integrates
advanced machine learning techniques to address the challenges in noise source identification. With the advent of IoT Noise Monitoring Terminals, the conventional manual auditory analysis methods have become less feasible. Our research explores the application of convolutional neural networks
(CNNs), a standard in environmental noise analysis, and assesses the emerging utility of Transformer Neural Network (TNN) models in this domain. The aim is to conduct an objective comparison of these models, applying them to identical datasets to determine their effectiveness in identifying
noise sources. Through this analysis, the study seeks to contribute to the field of environmental acoustics by offering insights into the comparative strengths and limitations of CNN and TNN models.