bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparing outdoor sound propagation simulations based on geometrical and numerical methods
Authors: KRAXBERGER Florian , ADAMS Christian , DONNERER Julia , KALTENBACHER Manfred , SCHODER Stefan
Published: October 2024

Conventional simulations of outdoor noise propagation often rely on geometrical acoustic methods such as ray tracing or mirror sources. Especially for low frequencies, these methods deliver physically implausible results due to their inherent approach not resolving the properties of
the acoustic field. In this contribution, the results of a conventional noise propagation simulation software based on geometrical acoustics are compared to numerical results originating from solving the Helmholtz equation with the Finite Element Method (FEM). A 2.6 km long cross-section through
an alpine valley with a railway line is considered as an exemple. In comparison with the FEM results, the shortcomings of geometrical acoustic methods are demonstrated, which underline the need for powerful and computationally efficient numerical approaches for outdoor noise propagation.
Ten years of experience with road noise auralisations
Authors: FINNE Per , THYSELL Erik , EGEDAL Rune
Published: October 2024

For more than a decade, The Danish Road Directorate has used auralisations to communicate the future road noise impact to the public. Auralisations are add-ons to the mandatory noise maps and assessments of noise exposed dwellings and people. Moreover, auralisations are very useful
for public presentations like EIA etc. Road noise auralisations and presentations have been made to give the road's neighbours an impression and understanding of the impact, the road will have on the environment. Additionally, auralisations have been shown to be a very powerful tool in terms
of explaining general acoustic terms and sound propagation e.g. the influence of wind direction and speed and the efficiency of future noise barriers of various heights. Presentation formats range from webpages to auditory presentations with calibrated headphones and overlaying introducing
speak giving exact sound levels for the audience. Even videos and recorded soundscapes from specific locations have been used to create auralisations that are more trustworthy and recognizable for the audience. This presentation gives an overview of different formats of presentation and summarizes
our experiences so far with different auralisations suiting the various cases of road projects. The use of simple auralisasions in Dynamic Noise Monitoring Maps will also be touched.
An analysis of tire radiation properties using dispersion diagrams
Authors: HIRTHE Eugenia , HOEVER Carsten , TSOTRAS Achillefs
Published: October 2024

Road traffic noise created by tire/road interaction not only depends on the road surface properties and the tire tread pattern geometry, but also on the tire construction. Besides the footprint shape, the tire construction can also affect the radiation efficiency of the tire modes.
Dispersion diagrams represent the circumferential mode number of a mode shape as a function of its natural frequency. Identification of key branches in the dispersion diagram for a tire can help in understanding tire noise radiation under working conditions. After performing a cluster analysis,
where all points belonging to the same branch associated with a particular cross sectional mode shape deformation are identified, differences in tire specification are considered, and their respective dispersion diagrams are compared. First results reveal that by changing the tire stiffness
(e.g. by increasing belt angle or inflation pressure) the shape and slope of the different branches are changing. Which branches remain unchanged, and which are most sensitive to these changes can reveal how differences in tire structural composition influence the modal wavelength and consequently
the radiation efficiency of the different modes.
Investigate the contribution of natural convection to the complex temperature distribution in a thermoacoustic core using experiments
Authors: FONTBONNE Martin , RAMADAN Islam , POIGNAND Gaëlle , VALIÈRE Jean-Christophe , BAILLIET Hélène
Published: October 2024

This study focuses on the influences of natural convection on the temperature distribution in a compact thermoacoustic coaxial heat pump. The behaviour of this device is quite consistent with results of Rott's linear theory of thermoacoustics, but early measurements reveal a non-uniformity
of the temperature along the transverse dimension of the core, as well as nonlinear axial temperature profiles. To investigate the contribution of natural convection on these temperature distributions, a hanging system allowing the device to be rotated around 2 axes is implemented. For each
configuration, temperature at various locations in the thermoacoustic core is recorded using an array of 3 by 5 thermocouples, and heat balance in the core is performed. All the experimental data are analysed to provide a better understanding of the heat flows in the device.
Characterisation of metamaterials for underwater acoustics using the 5-point method
Authors: LARCADE Clément , CROëNNE Charles , POUILLE-FAVRE Monique , ROUX Laetitia , HLADKY Anne-Christine
Published: October 2024

The characterization of metamaterials by measurement is essential to reveal the true efficiency of a material's reflection and transmission in water. The current 3-point method developed by L. Roux et al, J. Acoust. Soc. Am. 147, 2 (2020) 1104-1112 provides important advantages, such
as consideration of the pressure field diffracted by the edges of the panel and late reflections, due respectively to the finite size of the panel and the water tank. However, this method only considers specularly reflected and transmitted waves. For metamaterial panels based on periodic arrays
of macro-inclusions there exists a diffraction cut-off frequency, above which several propagating waves are generated in water, with frequency-dependent propagation directions, in both the reflected and transmitted fields. Due to this multiplication of waves, the 3-point method is no longer
adequate. The 5-point method consider these components, in addition to those considered by the 3-point method allowing measurement beyond the material's first cut-off frequency by using 5 hydrophone position instead of three. Tests were carried out on a panel with an adaptable grating periodicity
to test the robustness of the 5 points method. Results are compared with the 3-point method when both are valid and numerical results obtained by FEM.
Target setting and practical Improvement for sound quality of electric vehicles
Authors: XIE Xiaolong , ZHANG Shengming
Published: October 2024

For electric vehicles, because there is no masking effect of combustion engine noise, the middle frequency and high frequency noise of electric components become distinct and annoying. Electric driven unit, electric compressor, electric pump, and motors of seat adjusting device are
always major noise sources for electric vehicles. Some of those noise signals are steady, some are transient and some are time-variable. So only SPL is hard to reflect human's true perception. Psychoacoustic metrics, such as loudness, roughness, sharpness, and tonality, is hard to evaluate
all complicated NVH phenomenon of electric vehicles using one metrics. In this paper, the author tested different operation noises of above-mentioned electric components of several popular EVs, and finalized proper psychoacoustic metrics for different operations based on loudness, modulation,
tonality and objective evaluation. Furthermore, the author studied target setting for dedicated metrics, and effective improving methods for sound quality of EVs from the point of source and path. For example, effective designing for acoustic encapsulation of EDU and electric compressor, and
good insulation performance designing for dash inner and trunk floor trim. Keywords: Sound quality, Psychoacoustic metrics, electric vehicle, objective evaluation, target setting
Research of perceptual descriptors discriminating clarinet reeds of identical stiffness
Authors: GAILLARD Amélie , GAZENGEL Bruno , KOEHL Vincent
Published: October 2024

From the musician's point of view, reeds considered as identical by the manufacturer (same cut, same strength and same brand) may exhibit large perceptual difference in terms of musical qualities. Past studies, carried out with clarinetists or saxophonists, have revealed that the reeds
were mainly differentiated on the basis of their ``ease of playing'' which appears as the main perceptual descriptor of reed quality. This descriptor proved to be correlated with the reed stiffness measured at its tip in either static or dynamic conditions. The current study aims at discovering
if other perceptual descriptors can be used to differentiate between reeds that would obtain similar ``ease of playing'' assessments (i.e. that exhibit the same stiffness). Firstly, the reeds are sorted on the basis of stiffness measurements carried out at the reed tip by using an artificial
musician. Secondly, reeds of equivalent stiffness will be selected for perceptual assessment by professional clarinet players. As this selection process might result in subtle differences between reeds, the musicians will be asked to differentiate between them by using a three-interval three-alternative
forced-choice (3I3AFC) response paradigm. In addition to this perceptual assessment, the subjects will be asked to verbally describe their criteria for reed differentiation.
Potential of data-driven discovery of nonlinear wave equations
Authors: HRUšKA Viktor , FURMANOVá Aneta , BEDNAříK Michal
Published: October 2024

Data-driven partial differential equation discovery techniques have been growing in importance in recent years. This paper discusses its possible applications in the field of finite-amplitude sound propagation and the related phenomena (such as generation of higher harmonics and shock
formation). Two cases are investigated, namely the propagation of pressure pulses as travelling waves and the interference of pressure pulses, the former leading to the Westervelt equation and the latter to the Kuznetsov equation. It is shown how representative wave equations can be extracted
from data obtained by numerically solving the compressible Navier-Stokes equations (up to the third order smallness in entropy changes) and subsequently employing the sparsity promoting regression techniques. The resulting error of the equation coefficients is about 7% in the nonlinear terms.
The limitations of this approach are discussed (e.g., the appropriate capturing of thermal and viscous loss terms).
The effect of aircraft noise on noise annoyance in DEBATS and NORAH pooled analysis: Role of non-acoustic factors
Authors: KODJI Minon'tsikpo kossi , SPILSKI Jan , LACHMANN Thomas , NIEDEN Anja zur , LAFONT Sylviane , LANOY Emilie , SCHRECKENBERG Dirk , EVRARD Anne-Sophie
Published: October 2024

We investigated the dose-response relationship between aircraft noise levels and noise annoyance in the French DEBATS study including 1244 participants in 2013 and a sub-study of the German NORAH study including 1039 participants in 2014. In both studies, annoyance due to aircraft noise
was assessed using the ICBEN 5-points question. High annoyance was defined according to ISO/TS-15666 (HAV). Outdoor aircraft noise levels were modelled for the participants' home addresses. The moderation roles of noise sensitivity, gender and age were investigated. About 18% of the participants
in the DEBATS study reported to be highly annoyed vs 54% in the NORAH study. The mean noise levels (Lden) were similar (54 dBA in DEBATS and 52 dBA in NORAH). In the pooled analysis, high noise annoyance was associated not only with aircraft noise levels, but also with non-acoustical factors
such as noise sensitivity, age and trust in authorities. Noise sensitivity moderates the effect of aircraft noise levels on aircraft noise annoyance (p-value of interaction = 0.02), while age and gender do not.
Low-frequency broadband acoustic ventilation meta-barrier based on consecutive multiple Fano resonances
Authors: XU Zixiang , XIA Yifei , CHEN An , YANG Jing , LIANG Bin , CHENG Jianchun
Published: October 2024

Acoustic metamaterials utilizing Fano resonance provide the possibility of simultaneous airborne sound insulation and high-performance ventilation. However, the ultra-sharp line shape results in a narrow working frequency range, which is still insufficient for practical applications.
In this work, we propose a low-frequency acoustic meta-barrier supporting consecutive multiple Fano resonances (CMFRs) with broadband (~75%) capability, efficient ventilation, and ultra-thin thickness, etc. The barrier features a binary metastructure, incorporating a chiral space coiling tunnel
and a hollow pipe in a planar arrangement. This configuration offers discrete and continuous states within the composed Fano system, corresponding to the tunnel and the pipe, respectively. By means of superposition of multi-order Fano resonance modes, the destructive interference between the
discrete and continuum states keeps effective in a broad frequency range, while simultaneously achieving high air permeability. Numerical results of transmission loss show significant attenuation of incident energy in the range of 479-1032 Hz. Our work lays the groundwork for next generation
of Fano-based metamaterial applications, with far-reaching implications for noise control and related fields.
Design and optimization of acoustic reflector for uniform diffusion
Authors: HE Mu , LUO Wei-Zhi , XIA Liang
Published: October 2024

Sound diffusion performance is considered as an important issue in building acoustics. A well-diffused sound field can effectively enhance the human listening experience. To this end, we have investigated several optimization strategies to design a sub-wavelength acoustic metasurface
that can achieve broadband uniform diffuse reflections. These designs are based on Fresnel lens surface, groove-like structure, level-set method, topology optimization approach, respectively. Meanwhile, a strategy combining Monte-Carlo searches and other derivative-free algorithms has been
analyzed and used to ensure, as far as possible, a global optimum for the objective function when dealing with the multi-peak problem encountered in complex sound fields. Numerical simulations show that the resulting metasurfaces with the best diffusion performance have similar configurations
between different design methods. The simulated sound pressure field was also verified by experimental measurements. From a general perspective, the proposed optimization strategy and simulation framework can provide a greater degree of freedom for geometric configuration and benefit the design
of interior components in building acoustics.
Investigation of the vibro-acoustic signature of a heat pump through an experimental transfer path analysis
Authors: NEVES Lucas , MOREIRA Rui , HERBST Juergen
Published: October 2024

With the increasing interest on heat pumps due to their energy efficiency and environmentally favorable characteristics, concerns regarding their operational noise and vibration levels are becoming paramount, particularly in residential applications where occupant comfort is a priority.
A heat pump consists of significantly distinct components regarding their physical properties, contributing to a complex dynamic system with respect to noise and vibration. To better understand its vibro-acoustic signature, this work presents an experimental transfer path analysis (TPA) of
an outdoor unit of a heat pump system for residential applications. In this study, the main noise sources and the predominant vibration and noise paths are identified. Predictions of the total and partial responses at the receiver side is determined in order to quantify the contribution of
each individual path. For the determination of the operational internal forces, the inversion matrix method is adopted. The findings of this study can contribute to the development of effective design guidelines and engineering solutions for minimizing the acoustic and vibrational footprint
of residential heat pumps.
Prediction and observation of regional infrasound from the OSIRIS REx re-entry capsule
Authors: BLOM Philip , BISHOP Jordan , WEBSTER Jeremy
Published: October 2024

Infrasonic signals produced by bolides and space debris passing through atmosphere are frequently observed at notable stand-off distances. The acoustic energy radiated from such objects is dominated by the aero-acoustic Mach cone which exhibits a highly directional radiation pattern
dependent on the velocity of the object relative to the surrounding atmosphere. Recently, a mapping of the Mach cone geometry into acoustic ray tracing methods has enabled efficient regional simulation of infrasonic ensonification from such sources. In September 2023, the OSIRIS REx sample
capsule returned to Earth as part of a NASA supported asteroid study and a number of institutions deployed sensors to measure geophysical signatures of the event. The anticipated capsule trajectory was combined with historical atmospheric data for September in the western United States to
predict likely regional ensonification during re-entry. Los Alamos National Laboratory infrasound experts deployed microbarometer arrays in locations predicted to be ensonified and were able to identify signals with arrival times and direction-of-arrival consistent with the capsule re-entry.
An overview of the predictions, field deployments, and identified signals will be presented.
Application of Cadna/A software to the prediction of traffic noise on residential envelope sound insulation
Authors: LI Shujie , WANG Hongwei , DENG Yulong , ZHANG Wenzheng
Published: October 2024

The primary issue influencing residential structures' interior sound insulation environments is urban traffic noise. When choosing sound insulation for residential windows and doors, it is essential to consider the influence of road traffic noise. In conjunction with the examples, a
three-dimensional simulation prediction model is created early on using Cadna/A software, and it is configured in accordance with the measured data of the road environmental noise to predict the sound pressure level of the outer surface of the residential building's enclosure structure at
various locations and floors. This serves as a foundation for choosing the residential building's interior sound-insulated windows and doors as well as for the building's construction. In order to confirm that interior doors and windows are structurally sound-insulated, sound insulation measurements
of typical residential sample buildings are made later in the building process.It offers some reference value for using Cadna/A in the assessment and forecasting of traffic noise's impact on the soundproofing of residential building envelopes.
Research on the influence mechanism of park landscape characteristics on psychological perception around expressway based on soundscape theory: a case study of Chengdu Bailuwan Wetland Park
Authors: SHAO Yuhan , LU Jiayi , ZHANG Zhoutao , JIN Tongfei
Published: October 2024

With the continuous development of China's transportation infrastructure strategies and urbanization, urban road networks have seen ongoing improvement. Yet noise pollution along expressways is gradually becoming a prominent issue within the broader challenge of urban noise. Noise control
has recently emerged as a bottleneck for building livable cities, while well-designed landscapes can improve the quality of psychological perception. By precisely quantifying the multi-sensory composite perception characteristics of urban green space landscapes, this research explores the
mechanism through which such landscapes influence psychological perception. The study site was selected in Bailuwan Wetland Park, Chengdu. Objective and subjective environmental data and questionnaire feedback were collected through sound walks and big data analysis based on the geographic
information system, after which quantitative analysis was conducted on how landscape environmental characteristics influence environmental experiential perception. The research explores the mechanism of the influence of the regulation of landscape environment characteristic elements on psychological
perception and constructs a visual prediction model to provide a universal theoretical basis and methodological support for the planning and regulation of urban green space landscape along expressways, which is of positive significance in guiding the regulation of landscape space.
Best descriptors for predicting noise annoyance and spectrum-based penalty of steady-state wideband noise
Authors: KUUSINEN Antti , HONGISTO Valtteri
Published: October 2024

Many objective descriptors (i.e., single-number quantities) are available in the literature for the objective assessment of noise annoyance of wideband, steady-state sounds. However, there is no definitive understanding of which descriptors best correspond to subjective annoyance. Our
purpose is to assess how different descriptors correspond with differences in noise annoyance resulting from changes in A-weighted sound level and spectrum. This investigation is based on recently published results from a psychoacoustic experiment conducted by Kuusinen et al. [1]. They investigated
23 steady-state wideband noises with various spectral shapes within 32-48 dB LAeq, and participants rated them in terms of subjective annoyance. The study revealed that penalty due to spectrum shape could be even 10 dB. Here, we present a follow up analysis focusing on objective noise descriptors.
The results indicate that many descriptors are strongly associated with noise annoyance ratings, while Spectral Centroid and Sharpness appear to be the best candidates to predict spectrum-based penalty.
Introducing the concept of acoustic personalised environmental control systems (Acoustic PECS) within the framework of IEA EBC Annex 87
Authors: TORRESIN Simone , AL-ASSAAD Douaa , ALETTA Francesco , BALDERRAMA Alvaro , BIVOLAROVA Mariya P. , DE SOUZA Larissa Pereira , DICLE Seda Yuksel , LEE Pyoung-Jik , LLORCA-BOFí Josep , MAULA Henna , PIGLIAUTILE Ilaria , PISELLO Anna Laura , WU Zhibin
Published: October 2024

The availability of systems that can locally adjust environmental parameters holds the potential to enhance building occupant satisfaction by considering individual sensitivities, expectations, and needs. To this aim, Personalised Environmental Control Systems (PECS) are being studied
as solutions that can provide individually controlled environments in the immediate surroundings of an occupant, without affecting directly the entire space and other occupants' environment. The concept has been primarily developed to address individual control of the thermal environment and
perceived air quality, as in chairs with heating/cooling functions and desks equipped with personalized ventilation systems. By extending the concept of PECS to the acoustic domain, a framework on Acoustic PECS is here introduced and exemplified. The study builds on ongoing research within
the IEA EBC - Annex 87, dedicated to investigating the Energy and Indoor Environmental Quality Performance of Personalised Environmental Control Systems.
Sound environment design using flexible wood-based sound absorbers
Authors: UEMURA Tomoaki , HASHIMOTO Norihisa , SUGIYAMA Hiroyuki
Published: October 2024

A sound-absorbing material made of flexible wooden boards with air permeability was developed to improve the indoor sound environment of buildings. The flexible wood-based material has sound absorbing characteristics with the Helmholtz resonator by its air permeability. In other words,
various sound absorption characteristics could be realized owing to the cross-sectional shape (flat or curved) and machining conditions (cut width, cut pitch, and plate thickness). In this paper, the application of flexible wood-based sound-absorbing materials to acoustic design in actual
buildings (nursery schools and a church) where acoustic considerations are required is presented. In their application to a newly built nursery school, one of the considerations was to prevent the loss of design by installing sound-absorbing materials. In their application to acoustic renovation,
the sound environment improvement effect was confirmed by measuring sounds before and after the installation, and it was also confirmed that the users were able to feel the improvement effect. These results will lead to the development of sound-absorbing wooden boards as an interior material
and the promotion of the use of wood in buildings to contribute to the realization of a decarbonized society.
Highlighting the effects of gravity in a compact thermoacoustic heat pump
Authors: BALTEAN CARLES Diana , WEISMAN Catherine , FRAIGNEAU Yann
Published: October 2024

We present a numerical study of gravity impact on thermoacoustic heat pumping effects in a compact cavity used as a refrigeration device. More precisely, we show how gravity acts on the temperature distribution, on the mean temperature heat flux along the stack area and on flow dynamics.
Studies are performed in a two-dimensional geometrical configuration which is simplified with respect to common experimental devices but sufficiently detailed to take into account the main physical mechanisms. Fluid motion, heat and mass transfer as well as compression/expansion effects are
estimated from the computation of the Navier-Stokes equations in the low-Mach number hypothesis coupled with the heat equation in solid parts. The low-Mach number hypothesis is here relevant because the characteristic scale of the acoustic wavelength is much smaller than the geometrical length
scales of the cavity. The operating mode is characterized by a moderate drive ratio, a fluid oscillating motion of moderate amplitude and fixed low frequency, typical of such devices. It is shown that when gravity is included, buoyancy effects modify the temperature and velocity fields as
well as heat pumping efficiency.
Revisiting reverberation formulae
Authors: POLACK Jean-Dominique
Published: October 2024

In 1992, the author proposed a generalization of Sabine's formula that develops reverberation time over a series of powers of the reflection coefficient on the boundaries. Some years later, he reduced the development to just two terms that made it possible to monitor reverberation times
up to large absorptions. The present paper revisits this development and justifies it with the help of free path statistics in 3D rectangular enclosures. It proves that Kuttruff's reverberation formula is a special case of the general formula, but diverges for large absorption. Reverting to
Kuttruff's original integration process leads to a formula that does not diverge. The paper further explains the difference between Eyring-type reverberation times that vanish for total absorption, and Sabine-type reverberation times that never vanish even for total absorption, and proposes
a simple scheme for evaluating the asymptotic free path statistics and thus improving reverberation time prediction. Lastly, the approach is extended to non-ergodic enclosures.
Time-delay feedback control on vertical vibration of maglev train under unsteady aerodynamic force
Authors: LI Jia Xuan , LIU Xiang
Published: October 2024

The stability and safety of maglev trains are significantly affected by unsteady aerodynamic forces during high-speed operation. In this paper, we employ a time-delay feedback control strategy to suppress the nonlinear vertical vibrations of maglev train under periodic unsteady aerodynamic
force. Firstly, the amplitude-frequency response equation of the maglev vehicle is derived using the multiple scales method, and the stability of the steady-state solutions is determined. Then, the influences of velocity feedback gain coefficient and velocity time delay on the nonlinear vibrations
of the maglev vehicle are investigated. The optimal value range of the time delay is identified. The results demonstrate that the time delay feedback control can effectively suppress the nonlinear vibration of maglev vehicles and enhance their operational stability under the premise of reasonable
selection of time delay parameters. The theoretical research presented in this paper can serve as a theoretical reference for the design, improvement, and optimization of control systems for high-speed maglev trains.
Sound absorbing chandeliers for multitalker noise control in large halls
Authors: REYNDERS Edwin , VAN DEN WYNGAERT Jan , VERMEIR Gerrit , VERLINDEN Marie
Published: October 2024

During social gatherings in large halls, multiple conversations taking place simultaneously can lead to very high noise levels. Increasing the amount of sound absorption in the hall can be very effective in this context: due to the Lombard effect, the noise level drops with 6 dB when
doubling the equivalent absorption area, while only a 3 dB drop occurs for sources of constant sound power. However, the possibilities for the absorptive treatment of existing venues can be highly limited, especially when dealing with architectural heritage. Therefore, in the present study,
sound absorbing chandeliers, consisting of dense arrangements of absorbing objects, have been designed, developed, tested, and applied in a hard-walled historic hall that hosts social gatherings of more than 800 people. Experiments in the hall during busy events have confirmed the effectiveness
of the chandeliers, yet it was also found that, since the ceiling has become the main absorptive surface, they loose efficiency due to the resulting sound field directionality. Furthermore, the individual vocal effort was observed to stay constant when the background nose level was decreasing.
Both effects have been thoroughly studied and analyzed, and a prediction methodology to account for these effects has been proposed.
How sustainable are low-noise pavements? Answers from a life-cycle-assessment including the use-phase and noise mitigation of typical Swiss pavements
Authors: SCHINDLER Johannes , BRAUNSCHWEIG Arthur , HUWYLER Rolf , BüHLMANN Erik
Published: October 2024

Despite continuous efforts to reduce road noise emissions, road noise is still the dominant source of noise in Switzerland. Low-noise pavements are an effective measure for road noise mitigation, but besides their higher cost, their major drawback is a reduced service lifetime as compared
to conventional pavements. How do these arguments compare in a comprehensive view? To address this question, we performed a cradle-to-grave life-cycle-analysis of four different pavement types: a conventional pavement as reference, two types of semi-dense low-noise pavements and an acoustically
optimized type of asphalt concrete. Besides the needed raw materials, the construction, maintenance and demolition, this life-cycle-analysis also includes the use-phase of the road. Thus, the noise mitigation (based on latest acoustic ageing models) and changes in fuel consumption (based on
rolling resistance) are included in the assessment. We evaluate the results in the dimensions of ecological scarcity, greenhouse gas emissions, primary energy consumption and life cycle costs. The impact assessment method "Swiss ecological scarcity" allows to weight noise emissions
and fuel consumption directly against resource demands of the different pavement types. Our results show that in densely populated areas, the noise reduction and energy savings clearly outweigh the increased resource demand of low-noise pavements.
The "effects of wind turbine sound on working memory" (a pre-registration plan)
Authors: GARCIA-GUERRERO Santi , O'HORA Denis , KING Eoin , MANOHARE Manish
Published: October 2024

Although research on the effects of wind turbine sound (WTS) over mental health factors is increasing, very little attention has been given to the potential effects of WTS over subtle cognitive processes, such as concentration or memory. The "brainwave entrainment hypothesis"
is rooted in neuropsychological research demonstrating that brain oscillations are modulated by external rhythms. In addition, perceived annoyance to wind turbines seems to be a phenomenon in which both visual and psychological variables interact with acoustic stimulation. However, annoyance
is a concept rarely operationalised in the literature. Our study aims to experimentally assess the effects of WTS on working memory. Working memory is recognised as a basic process, playing a crucial role in unconscious everyday processes (e.g., perceiving an object's trajectory despite input
interruptions when blinking), as well as deliberate processes (e.g., carrying out arithmetic operations). By exploring variations in performance during a memory task, while being exposed to WTS samples, we could highlight acoustic characteristics of the WTS stimuli that interfere-or not-with
cognitive processes. These data, combined with within-block ratings of annoyance, can provide us with index of annoyance directly related to the acoustic properties present in WTS recordings.
Application scenarios and opportunities of autonomous pass-by measurements
Authors: KIRCHHOFF Nikolas , MäNNEL Manuel
Published: October 2024

Traditionally, pass-by measurements of vehicles were performed manually along the roadside. Recent developments allow for such measurements to be performed autonomously. Without the labour-intensive need of a measurement engineer at the spot, a variety of new applications for pass-by
measurements become apparent. Beyond the application of the standardized SPB-measurement, a continuous and autonomous measurement of single vehicles can be used to detect high noise emitters. E.g., so-called posers or motorcycles increase the annoyance of inhabitants significantly. The detection
of these single events is an important step to advance noise protection. Furthermore, the steady collection of data leads to numerous opportunities to describe and categorize vehicle and road noise. It can be used to further investigate the change of the acoustic properties of the roads in
detail as well as those of the vehicles. The ongoing electrification of the vehicle fleet and the resulting changes in the noise behaviour can be scientifically tracked in real time. This progression affects next to the engine type (and sound) also the driving behaviour, the used tyres on
the vehicle, and more. A continuous collection of pass-by measurements will deliver an increased understanding of the different influential factors of the vehicle-road-interaction.
Characterization of wind turbine noise using psychoacoustical indicators
Authors: MANOHARE Manish , KING Eoin , MC KEOWN Eugene
Published: October 2024

Noise annoyance caused by wind turbines is a significant issue for people living in the vicinity of wind farms, leading to difficulty in its societal acceptance. Annoyance due to Wind Turbine Noise (WTN) has been regulated using conventional environmental indices, which often fail to
account fully the human perception of noise exposure. This study proposes the use of psychoacoustical indicators to assess the character of WTN in Ireland. Fourteen noise measurement locations were selected near wind farms in County Wexford (Ireland) with audio recordings made at each location,
when WTN was the dominant source. These recordings are analyzed to extract different psychoacoustic indicators and Zwicker's psychoacoustical annoyance. Further clustering of these sound samples was performed to understand the overall character of WTN and its associated annoyance. This characterization
provides an understanding of how the variation in psychoacoustical indicators might lead to changes in the perception of wind farm noise. These results can be employed to develop sound quality maps and further develop noise annoyance models complemented by conducting listening experiments.
Adapting to non-human listening agencies
Authors: KYTö Meri
Published: October 2024

One central concept in soundscape studies has been that of an acoustic community, i.e. a group of people sharing an understanding of a listened environment, either acoustic or mediated. This understanding manifests in recognition of sound sources, their communicative function and their
discoursive use in everyday life. The growing use of hearing aids, noise-cancelling headphones and other intelligent listening technology renders the soundscape more individual and at the same time introduces a non-human listening agency as a mediator to the individually calibrated soundscape.
This raises conceptual and methodological questions of listening abilities in general and of how the listening experience is to be understood as taking place in a shared environment. To illuminate this problematic the paper will present as a case how listening through cochlear implants and
their sound prosessors can be understood as a process of adaptation to a mediated acoustic community.
Time-domain simulation of sound propagation through anisotropic porous media for room acoustic applications
Authors: SHAPOSHNIKOV Kirill , HERRING JENSEN Mads , MONDET Boris
Published: October 2024

Wave-based room acoustic simulations require accurate modeling of sound propagation in the presence of extended (bulk) reacting porous absorbers. The sound absorption in porous media is typically addressed by means of equivalent fluid models that provide frequency-dependent effective
material parameters, such as density and bulk modulus. In the time domain, these frequency dependent properties result in the computation of convolution integrals, which is effectively handled via an auxiliary differential equations (ADE) method. In this work, we apply the time-explicit discontinuous
Galerkin approach to modelling of sound propagation in anisotropic porous media (with an anisotropic equivalent fluid model) together with the ADE method. We demonstrate the importance of using the extended approach for porous media, where the sound absorption depends not only on the frequency
and incident angle, but also on the travelling wave direction.
Correction for reverberation time in acoustic measurements from service and equipment - Comparison between different methods
Authors: CARRASCAL Teresa , CASLA-HERGUEDAS Belén , ROMERO-FERNáNDEZ Amelia
Published: October 2024

The measured values of the sound pressure level in ordinary rooms in dwellings vary depending on the combined effect of the absorption and the scattering of the furniture, or to the presence of absorbent surfaces on walls and ceilings. Regarding the measurement of noise from building
services, ISO 16032 and ISO 10052 methods allow to normalize the sound pressure levels to a reference reverberation time of 0,5s. Several European countries incorporate this reverberation time correction into their regulations. However, Spanish regulations, specifically RD 1367/2007, and the
majority of regional decrees and ordinances concerning the evaluation of noise from activities or equipment within buildings, do not incorporate this correction, even when measurements are performed in two scenarios: before the building's occupation when rooms are empty, or when the building
is fully furnished, as may occur in the case of complaints. For that reason, this study compares the values of the reverberation time index obtained in 180 residential rooms using various methods while also evaluating the benefits and drawbacks of their application.
The LIFE SILENT project's approach to sustainable noise mitigation
Authors: BELLUCCI Patrizia , GARAI Massimo , PRATICò Filippo Giammaria , LICITRA Gaetano , CIARALLO Francesca
Published: October 2024

The main objective of the LIFE SILENT PROJECT is the development of sustainable and eco-friendly solutions to mitigate noise in complex urban environments, where multiple and diverse noise sources, mainly roads and railways, coexist across densely populated areas. Mitigating noise in
such environments generally excludes the use of solutions that might interfere with the urban context, such as noise barriers. This is mainly due to the proximity of receivers to the noise source, which reduces the visibility of the surroundings and air circulation, leading to microclimatic
modifications and social opposition. This is why noise mitigation measures acting directly on the source are recommended, such as low-noise pavements for roads, and dampers, rail grinding, and silent brakes for railways. However, these solutions suffer from either durability issues or high
implementation costs. Thus, an improvement is necessary. In the LIFE SILENT project, innovative and sustainable low-noise and long-lasting pavements, as well as low-height noise barriers will be developed and demonstrated in a real test environment. Additionally, procedures will be established
to facilitate their synergistic implementation, providing transport infrastructure owners and managers with solid information to support their widespread adoption. In this paper, a general overview of the LIFE SILENT project is given.
Investigation of perceived annoyance in indoor workplaces using short and ultra-short sound samples
Authors: HOSSAIN Md Robiul , KING Eoin A.
Published: October 2024

Typically, metrics crucial for assessing sound quality are derived from high-quality audio samples obtained in controlled environments. However, due to the sensitive nature of workplace settings, recording audio samples on-site becomes impractical. Privacy emerges as a significant concern
for all when collecting audio samples. Consequently, best practice would require that all analyses must occur either locally on a device used to record audio or in the cloud, utilizing a purely mathematical approach. The paper aims to formulate methodologies for determining psycho-acoustic
sound quality metrics without the need to analyze audio data directly. This can be achieved by collecting and analyzing data in small batches. The variation of these metrics over these smaller samples can serve as an indicator of sound quality. Initiating the determination of values for psycho-acoustic
sound quality metrics such as loudness (N), sharpness (S), roughness (R) and fluctuation strength (FS) in short and ultra-short batches, followed by monitoring their variation over an extended period (e.g., 5 minutes), provides additional insight into the sound characteristics of the space.
Using the obtained psycho-acoustic sound quality metrics, we will explore the perceived annoyance among occupants through indoor soundscape assessments.
Experimental study of shooting sound around semi-open shooting ranges
Authors: SALOMONS Erik , EISSES Arno , VAN DIJK Didi
Published: October 2024

Measurements of shooting sound around semi-open shooting ranges are analyzed. Recorded sound signals show bullet sound and muzzle sound contributions. Time differences between bullet and muzzle sound pulses are explained by calculation of acoustical travel times. In general bullet sound
contributions are stronger in forward directions (angles 0 to 90 degrees with respect to the shooting direction) than in backward directions. A representative frequency is defined to characterize the relative importance of bullet sound in the emitted sound spectrum. This is further analyzed
by means of silencers on the firearms, as silencers suppress the muzzle sound but not the bullet sound. The effect of acoustical absorption material on the shooting range is also investigated. Differences of the order of 10 dB between different shooting ranges are attributed to acoustical
absorption material of the overhead screens (baffles) on the range. For practical applications it would be useful to represent a shooting range by a single point source with a direction-dependent sound emission spectrum. The accuracy of this approximation is investigated.
Annoyance caused by simultaneous exposure to noise and seat vibrations inside of a mini excavator: multimodal interaction and the effects of changes in low-frequency content of the sound signal
Authors: MARAVICH Maria Mareen , ALTINSOY M. Ercan
Published: October 2024

Drivers of commercial vehicles are exposed to noise and vibrations during their occupation. The signal characteristics of these exposures can lead to different degrees of annoyance perception, even below the legal daily exposure limits. In addition, simultaneous exposure to sound and
vibration may lead to potential interaction effects between the two stimuli, influencing the total annoyance perception. Therefore, a perception experiment was designed to ask the participants about the perceived total annoyance caused by simultaneous noise and seat vibrations in commercial
vehicles, presenting modified sound and seat vibrations, recorded inside of a mini-excavator. Multimodal interaction effects of noise and vibrations were investigated by changing the intensity of both stimuli. Furthermore, the influence of low-frequency signal components of the sound signal
with and without simultaneous seat vibrations was investigated by specific changes in the sound spectrum.
Optimization of an active device for global control of low-frequency wall reflections in a semi-anechoic room
Authors: FRIOT Emmanuel , PINHèDE Cédric , HERZOG Philippe , BOULANDET Romain
Published: October 2024

An active device has been designed and built at LMA to control low-frequency reflections on the absorbing walls of a semi-anechoic room: the sound pressure reflected by the walls in the presence of an unknown source is estimated by linear filtering of the total sound pressure near the
walls, then neutralized using acoustic sources placed on the walls. Here, we present 2D numerical simulations, involving monopole sources and series of damped analytic modes, which have enabled us to optimize the active device, in particular to (i) deal with resonance frequencies at which
cancelling the diffracted pressure near the walls is not sufficient to cancel it inside the room, (ii) minimize the number of the total pressure measurement points required to estimate the pressure diffracted by the walls at each location, and (iii) select the strategy for minimizing the virtual
signals corresponding to the diffracted pressure. Simulations show that with the optimized device, the control remains efficient up to frequencies corresponding to one wall source per wavelength and a little less than two pressure sensors per wavelength. Experiments are underway to compare
measurements with simulations.
Cascaded Thermoacoustic amplifier
Authors: FARHA Elie , MADDI Anis , POIGNAND Gaelle , PENELET Guillaume
Published: October 2024

In this study, we explore the amplification of an incident acoustic wave using the thermoacoustic effect and its applicability for low-temperature energy harvesting. The thermoacoustic effect can be exploited to develop thermoacoustic engines, whose potential for thermal energy harvesting
has been extensively studied. In their simplest form, they consist of a porous material inserted in a waveguide, in which a temperature difference is applied and leads to the generation of a thermoacoustic instability. Here, we propose the theoretical and experimental study of an alternative
system to the conventional thermoacoustic engine. The system considered here differs from the typical engine in that it exhibits no self-excited instabilities, but only relies on the amplification of an acoustic wave. The experimental set-up consists of a cascaded network of heated porous
materials, coupled to an acoustic source and an alternator. This device allows to control several parameters, such as the operating frequency and input power, and it can be designed to achieve a high amplification ratio. Our work offers a new perspective on energy harvesting using the thermoacoustic
effect.