bluuebunny/crossref_metadata_2025 huggingface dataset:
Numerical Analysis of the Flow-induced Whistling Noise of Ventilation Wall Based on Fluid-structure Coupling Method
Authors: Yu Qingqing , Xue Fei
Published: February 2023

As a widely used device in the field of air cooling and heat dissipation of electronic equipment, ventilation walls often have the problem of whistling caused by airflow. This paper presents a numerical study on the flow-induced whistling noise of a ventilation wall. Firstly, the interior
flow field of the ventilation wall under typical working conditions was calculated. Secondly, the structure wet mode of the ventilation wall was calculated considering the airflow influence on the structural vibration. Thirdly, taking the fluid pressure fluctuation at the surfaces of the ventilation
wall as excitation source, the structural vibration and radiation noise of ventilation wall was simulated, respectively. Finally, the structure of the ventilation wall was optimized to reduce the whistling noise. The results show that the high velocity airflow causes strong fluid-structure
coupling of the ventilation wall. Besides, the peak frequency band of whistling noise ranges from 112Hz to 125Hz, and the maximum sound pressure level (SPL) reaches 87.3dB. Moreover, by improving the structure of ventilation wall, the maximum SPL of whistling noise deceases about 10.5dB, which
significantly reduces the flow-induced noise. In conclusion, this paper could provide a method for reducing the flow-induced noise of ventilation walls.
Tactics Implemented at the University of Nebraska - Lincoln for Growing Inclusive Excellence in Engineering
Authors: Wang Lily
Published: February 2023

The percent of women and other underrepresented minorities who receive graduate degrees in engineering within the United States has been steadily increasing over the past 25 years, but it remains under 25%. Many colleges of engineering in the United States are implementing various methods
to improve culture towards achieving greater inclusive excellence, helping to support women and underrepresented minorities among their undergraduate, graduate, and faculty populations. In this talk, assorted tactics that have been used at the University of Nebraska - Lincoln will be discussed,
many of which could be incorporated into professional society activities. These include offering training on (a) recognizing implicit bias, (b) learning tactics to interrupt implicit bias, (c) growing the number of allies who actively support persons from underrepresented groups in our field,
(d) writing diversity statements to include in job applications, and (e) mastering non-violent communication skills. Additionally regular demographic and climate surveys should be conducted to gauge the levels of diversity and inclusivity in our professional societies. Descriptions of the
tactics and suggestions on how to deploy them in other organizations are provided.
Acoustic classification with the descriptor of the weighted standardized level difference DnT,w with use of the weighted apparent sound reduction index R'w
Authors: Neubauer Reinhard
Published: February 2023

Buildings must ensure sound insulation appropriate to their use. This sound insulation is regulated by building regulations. In many Europe countries this is by use of the weighted apparent sound reduction index R'w or the weighted standardized level difference DnT,w. This paper shows
that a direct assignment of the quantities R'w and DnT,w is only possible for certain geometric ratios of room volume and separating area (V/S). If a permissible deviation between R'w and DnT,w is accepted, a classification of the sound insulation values (R'w) with fixed class limits can be
made. This makes it possible to classify the sound insulation with reference to the descriptive parameter DnT,w using the weighted apparent sound reduction index R'w.
Effect of neighbours sounds in wooden residential buildings on restorative EEG rhythm (Alpha waves)
Authors: Frescura Alessia , Lee Pyoung-Jik , Jeong Jeong-Ho , Soeta Yoshiharu
Published: February 2023

The present study aimed to explore the effect of neighbours sounds commonly heard in wooden residential buildings on restorative EEG rhythm represented by Alpha waves. Thirty participants took part in a listening test which was performed to collect EEG data in distinct acoustics scenarios.
Noise sensitivity and attitude toward neighbours were introduced as non-acoustic moderators and assessed through questionnaires before the experiment. A series of impact and airborne sounds were presented through loudspeakers and subwoofer, while participants sat comfortably in the simulated
living room wearing the EEG headset (B-alert X24(r) system). The impact sound sources were two types of footsteps, adult walking and child running, recorded in a laboratory on different floor configurations and thus, varying in sound pressure level and frequency characteristics. The airborne
sound sources were a lively conversation and a piece of classical piano music, digitally filtered to represent good and poor sound insulation performances of vertical partitions. The effect of sound stimuli and non-acoustic factors on restorative EEG rhythm corresponding to Alpha waves (8-13
Hz) was then analysed. Differences in response to distinct acoustic scenario were observed. Additionally, Alpha band activity showed to be affected by noise sensitivity and attitude toward neighbours of participants.
A Preliminary Investigation of an Active Membrane-type Acoustic Metamaterial
Authors: Langfeldt Felix , Cheer Jordan
Published: February 2023

One of the most promising features of membrane-type acoustic metamaterials (MAM) is their anti-resonance at low frequencies, which typically exhibits sound transmission loss values that can significantly exceed the corresponding mass-law values. The bandwidth of this anti-resonance,
however, is usually very small, which limits the applicability of MAM in practical noise control problems. In previous research it has been shown that different types of actuators (e.g. magnets, electrodes, or pressurized air) can be used to adjust the anti-resonance frequency of MAM, for
example to adapt to changing tonal frequencies. However, these actuation principles require additional components to be added to the otherwise lightweight MAM. To overcome these limitations, this paper will present preliminary results from an experimental study of a smart MAM which has the
sensors and actuators compactly embedded within the added mass located at the center of the membrane of the unit cell. A small accelerometer is used to measure the vibration of the added mass and this signal is fed back to a controller, which is used to actuate the MAM using a small electrodynamic
exciter. An impedance tube is used to measure the sound transmission through the smart MAM and different control algorithms are compared.
The time-frequency characteristics analysis and prediction of ground vibration near a subway station
Authors: Liu Bideng , Wu Yubin , Song Ruixiang , He Lei , Wu Qiong
Published: February 2023

This paper presents the time-frequency characteristics of ground vibrations near subway stations through field tests and analyses. More than 15 ground vibration measurement points are set up in the longitudinal and transverse directions of the track near a subway station. Overall, the
ground vibration level (VLzmax) above the tunnel is approximately 73 dB on the border between the station and mainline, while it attenuates to 63 dB away from the tunnel by approximately 30 meters; the dominant frequency in the mainline area is approximately 63-80 Hz. The results in the longitudinal
direction show that the ground vibration increases rapidly as the train drives away from the station because of the train speed growing, and VLzmax is less than 10 dB between the station and near the mainline area, while the dominant frequency in the mainline area is higher than that in the
station area. The attenuation rate of the ground vibration in the transverse direction for the mainline area is faster than that for the station area. The power distribution law y=Ax^(-α) can describe the vibration attenuation characteristics, and its "peak and long tail effect"
and "scale-free characteristics" can predict the vibration at any position by measuring two specified locations.
Calculation of Drive-Related Structure-Borne Sound in Electric Driven Trains using Elastic Multi-Body Simulation
Authors: Noack Sascha , Beitelschmidt Michael
Published: February 2023

The structure-borne sound coming from the drive system defines especially for transient train manoeuvres the experienced interior noise of modern railway traction vehicles. A deeper look at the origin and the transmission of structure-borne sound is therefore of great importance to
increase passenger comfort in newly developed trains. The possibility of modelling the vibration behaviour of an electric multiple unit train up to the acoustic frequency range using elastic multi-body simulation (EMBS) has been investigated in a joint research project of the Chair of Dynamics
and Mechanism Design at TU Dresden and the company Alstom. Through usage of reduced order models of elastic bodies, the EMBS can be carried out in time domain in a computationally effi-cient way and non-linear system properties during motor run-up can be easily taken into account. Key research
findings with regard to model structure and necessary level of detail of individual components (e.g. tooth contact, electric motor, roller bearings, elastic bodies, hydraulic dampers) of the elastic multi-body model can be shown. For validation purposes, measurements on individual parts, a
motor-gear-unit test bench and the electric multiple unit on track have been carried out, results and comparison to simulation results can be presented.
Noise-related challenges in combined commercial and military operations at an airport
Authors: Marheim Jan Anders , Newman Michael
Published: February 2023

At Harstad/Narvik Airport Evenes, a NATO QRA detachment using F-35 fighter planes has changed the noise characteristics at the airport dramatically. The challenges of determining the correct health hazard values to avoid hearing damage on passengers and employees at an operating airport
is difficult. Initial noise mapping shows large areas around the terminal building and the car park with very high noise levels during F-35 take off using afterburner. The noise level increases rapidly during a take off but it is not comparable to an impact noise event. The focus of the work
is twofold; Finding the right noise limits to reduce hearing damage risk to an acceptable level at the same time as establishing noise abatement measures that is necessary to avoid hearing impairment to employees and passengers on their way to and from aircraft. A noise limit of LASmax = 115
dB is established.
Bayesian Parameter estimation of microphone positions, sound speed and dissipation for impedance tube measurements
Authors: Chen Ziqi , Fackler Cameron , Xiang Ning
Published: February 2023

With tube measurement widely used for acoustic measurements, calibration plays an important role in verifying and validating the measurement. This work applies a Bayesian method based on an air layer reflectance model to estimate the microphone positions, and sound speed in consideration
of environmental effects on uncertainties of the normal incident impedance tube measurements. Bayesian theorem is applied to estimate the microphone positions and sound speed given the experimental data obtained from the transfer function method (TFM) in tube measurements. With a hypothetical
air layer treated as material under test in front of a rigid backing in the tube, a parametric model is established for the TFM tube measurement to estimate the microphone positions using Bayesian inference. With the microphone positions accurately estimated, sound speed and losses due to
tube interior boundary effects are also estimated within the same Bayesian framework. Bayesian analysis results show that Bayesian parameter estimation based on the air layer model is well suited in estimating the sound speed, microphone positions, and other parameters to ensure highly accurate
tube measurements.
Examining the Difference Between Laboratory Measurements and Calculation Results in Impact Sound Insulation
Authors: Okay Mehmet , İlgürel Mehmet Nuri , Güçlü Rahmi
Published: February 2023

Architectural structures are designed and built to provide a comfortable living space to their users due to their function. One of the most important comfort expectations in buildings is acoustic comfort. Since the impact sound insulation between floors, which is one of the sub-headings
of acoustic comfort, is evaluated together with the floor covering, resolving the discomfort caused by incomplete or incorrect evaluations during the design phase can be both more difficult and more costly during operation. In practice, it has been observed that there are differences between
the laboratory measurements made according to the EN ISO 10140-3 standard and the calculations made according to the EN ISO 12354-2 standard for impact sound insulation. This difference can lead to an uncomfortable living space as the targeted acoustic performance cannot be achieved. This
situation creates the need for a calculation model that gives more realistic results during the design phase. In this study, the variables that cause the difference between laboratory measurements and calculation results in impact sound insulation will be examined and improvement suggestions
will be developed for the calculation of impact sound insulation according to the EN ISO 12354-2 standard.
Low frequency sound insulation of membrane-type acoustic metamaterials with negative pressure cavity
Authors: Xing Tuo , Li Xianhui , Zhao junjuan , Gai Xiaoling , Wang Fang , Guan Xiwen
Published: February 2023

The membrane-type acoustic metamaterial with negative pressure cavity (MAM-NPC) is designed to achieve low frequency sound insulation and tunable frequency on the duct side wall. A one-dimensional analytical method was used to discuss the sound insulation effect of MAM-NPC on the sidewall
of the duct. As the negative pressure increases, the first valley of sound insulation moves to high frequency. High sound insulation can be achieved in the low frequency range. The theoretical and finite element method results are compared. The one-dimensional analysis method basically agrees
with the finite element results in the low frequency band. Because only plane waves are considered in the one-dimensional analytical method.
The effects of workstation arrangements on the acoustical performance of the architecture design studios.
Authors: Hossam Eldien Hany , M. Bongwirnso Umaru , Alzaher Seraj
Published: February 2023

Architecture design studios spaces needs special treatment for its acoustical environment. Interaction, communication, meetings, and various activities could influence concentration, which in turn, affects other aspects as quality of the architectural concepts and creation level. Workstation
arrangement could consider as one of the elements which can improve the design studio acoustical conditions. In this paper, we evaluate the impact of 5 types of workstation arrangement with two different partitions heights (1.10m and 1.60m). The measurements were conducted in the College of
Architecture, Imam Abdulrahman Bin Faisal University, KSA. Speech Transmission Index, STI in the nearest workstation, Distraction distance rD, privacy distance rP, A-weighted background noise level Lp, A, B and A-weighted SPL of speech at 4 meters Lp,A,S,4m have been measured according to
ISO 3382-3. We found that U-shaped workstation arrangement can improve the acoustical environment the design studio. Furthermore, good results were observed using 1.60m partition height for all types of arrangements.
Study on the scoping prediction of railway-induced environmental vibration based on transfer learning
Authors: Liang Ruihua , Liu Weifeng
Published: February 2023

While the urban rail transit infrastructure provides convenience to the people, environmental vibrations and radiated noise generated by its operation can also affect the residents in the surrounding buildings. Therefore, during the preliminary design stage of railway lines, extensive
vibration scoping prediction needs to be carried out, which can promote reasonable vibration mitigation design, thus minimizing the impact of the railway induced environmental vibration. Considering the limitations in the accuracy of existing methods, a deep learning-based vibration scoping
prediction model is proposed in this paper. Moreover, the transfer learning strategies are used to enable the model to be trained with the railway induced vibration data obtained from both numerical simulations and field measurements, which allows the model to be trained more sufficiently
and thus achieve higher prediction accuracy while keeping high efficiency. To validate the performance of the proposed method, a case study is presented. Specifically, vibration data under different conditions obtained from numerical simulations and measurements are used to train and test
the deep learning-based models using transfer learning strategies. Then, by comparing the performance of the trained model with the existing scoping methods, the feasibility and advancement of the proposed method are demonstrated.
Acoustic assessment of the St Spirit's church in Aversa (Italy)
Authors: Lombardi Ilaria , Bevilacqua Antonella , Guerriero Luigi , Trematerra Amelia
Published: February 2023

The St Spirit's church of Aversa, in Italy, is part of the rich clerical patrimony in Baroque style. The earthquake occurred in 1732 determined the collapse of the entire vaults and roof, left in ruins for different centuries. Restoration works started at the end of the 20th century
have been commissioned by the local authority to adapt the conditions of the architecture to classical music besides the sacred functions. This paper deals with the acoustic assessment of the St Spirit's church after the construction of a double-slope roof and the realization of vaults by
employing exposed canes. Acoustic measurements undertaken inside the church represent the basis to determine a new acoustic design focused on the integration of temporary music venues. As such, a variety of solutions related to finish materials and additional acoustic panels have herein proposed
to achieve optimal values for live musical concerts.
Active control of interior road noise using the remote microphone technique
Authors: Zhang Zhe , Shi ChenLu , Lv Xiao , Ling ZiHong
Published: February 2023

A multichannel feedforward headrest system for the active control of interior road noise in a vehicle cabin is built. The remote microphone technique is applied, which enables the estimation of the sound pressure responses at the passenger's ear positions without direct deployment of
error microphones there. The optimal observation filter for the remote microphone technique is formulated in a so-called training stage using signals measured at two error microphones on the passenger's ears and an array of four to five monitoring microphones on the headrest, passenger seat
and vehicle ceiling. The estimation accuracy of the observation filter is investigated through simulations and road test. Regarding the causality error encountered in a certain test case where the passenger leans forward, thus making the noise signals arrive at the monitoring microphones prior
to the error ones, a delay factor is added into the original remote microphone technique to correctly compensate for the time delay. The noise attenuation performance of the active headrest system is then experimentally and subjectively determined, indicating a larger noise abatement in a
wider spatial environment by applying the remote microphone technique.
Non-normative sonic space: exploring the divergent capacities of soundscape design in the built environment
Authors: Renel William
Published: February 2023

This paper aims to situate disabled and neurodivergent people's experiences at the heart of research concerning human perception and response to soundscape design in the built environment. The paper outlines the process and insights gained through a series of participatory binaural
soundwalks held in London between 2016 - 2019. Each soundwalk invited a disabled and/or neurodivergent person to discuss their experiences of and responses to soundscape and acoustic design whilst walking through a public environment such as a gallery, café or theatre. The chapter uses
a multimodal framework for discourse analysis to analyse the soundwalk data, highlighting the divergent and non-normative affective potential of sound in socially public spaces. Findings consider elements such as how changes in reverberation time may trigger involuntary words and noises for
people with Tourettes and how a lack of understanding of noise levels might increase anxiety for people with post-traumatic stress disorder. By generating new knowledge and understanding of the divergent capacities of soundscape design to affect and be affected by people within the built environment,
the chapter aims to increase the opportunity for researchers across disciplines to think critically about the societal repercussions of design that privileges a normative ear, body and mind.
Calculation of annual aircraft noise exposure for Geneva and Zurich airports with the next-generation program sonAIR - first results
Authors: Schalcher Stefan , Zellmann Christoph , Meister Jonas , Wunderli Jean-Marc , Schäffer Beat
Published: February 2023

The next-generation aircraft noise simulation program sonAIR was designed to precisely predict single flights with the scope of investigating and optimizing noise abatement flight procedures. Recently, sonAIR was implemented in a geographic information system (GIS) to make it suitable
for noise mapping calculations of entire airport scenarios. In this study, we conducted first calculations of annual aircraft noise exposure with sonAIR for Geneva and Zurich airports, Switzerland, for the year 2017, simulating several 10'000 single flights and accounting for real conditions
in great detail (e.g., detailed emission modelling and considering ground cover in the sound propagation calculation). Our calculations proved the ability of sonAIR to do annual aircraft noise calculations with many simulated flights. Comparing the results to those obtained with the best-practice
program FLULA2, which is currently used for official aircraft noise calculations in Switzerland, we found that the noise contours differ on average little in areas with legally relevant noise exposure. However, locally larger differences may occur, primary due to varying ground cover and more
detailed sound emission modelling. In this contribution, we present the process of sonAIR for annual aircraft noise calculations, show the most important results and discuss implications for future aircraft noise calculations around airports.
Virtual sound source perception challenges of binaural audio systems with head-tracking
Authors: Planinec Vedran , Jambrošić Kristian , Franček Petar , Horvat Marko
Published: February 2023

With the recent leaps in spatial audio technology, the use of binaural head-tracking for spatial audio can revolutionize the way how music and audio are experienced. Moreover, to research noise-related perception in laboratories, binaural head-tracking is frequently used as an audio
reproduction system. Although this technology is getting significantly better in recent years, signal processing of binaural audio is often experiencing problems such as non-adequate sound source externalization and unacceptably high values of system response time since it influences the usability
of the technology at fast head rotation. In this paper, the results of an experiment are presented, in which test subjects are determining the direction of a virtual sound source in the horizontal plane with multiple parameter changes. The experiment is done in a controlled environment in
a listening room with known acoustical properties. Parameter variation includes: hardware head-tracker variation (commercial one and head-tracker based on simple embedded system), various software solutions for real-time binaural synthesis, and variation in the used Head-Related Transfer Functions.
The problem of externalization of a virtual sound source via headphones is discussed, and possible solutions to the problem are given. Results of the experiment and recorded data are presented.
Porous top layer optimization of cement concrete slabs for tyre/road noise reduction
Authors: Klein Philippe , Cesbron Julien , Bianchetti Simon , Gennesseaux Éric , Sedran Thierry , Waligora Julien
Published: February 2023

The I-STREET CUD-SF project aims at developing an urban pavement made of cement concrete slabs that can be easily removed and replaced for maintenance purposes. These slabs are made of a dense cement concrete body and a functionalized porous top layer ensuring water drainage and sound
absorption. In order to optimize the porous layer for tyre/road noise reduction, several mix recipes with different porosity and maximum aggregate size were considered. Recipes with the most interesting absorption properties were preliminary selected based on absorption coefficient measurements
performed on cylindrical test specimens with an impedance tube. A second phase was dedicated to evaluation of texture induced coast-by rolling noise levels with the tyre/road noise prediction model HyRoNE from 3D texture scans performed on rectangular laboratory samples. Finally, based on
a porous medium model and a propagation model considering the tyre/road noise source as an omnidirectional point source over an impedance plane surface, the porous layer thickness of the selected mix was adjusted to minimize the predicted noise at roadside for different reference rolling speeds.
This paper gives an overview of the results obtained at the different stages of the optimization process, prior in-situ assessment of the industrial solution in a near future.
Quantification of coin falling sound quality of coin processing machine
Authors: Terada Motoki
Published: February 2023

Quietness is essential for living comfortably but various noise exist at around our living place. Coins falling sound of the coin processing machine is one the noise around us. This noise disturbs our conversations, and it causes tired feeing occasionally. The coin falling sound is
unsteady sound and have various frequency characteristic during very short time. Hence, not only the sound pressure level but also the quality is considered to be important for the improvement. In this study, we focused on the sound quality of the coin processing machine and investigated the
impression through subjective evaluation test. In order to quantify the impressions, various coin falling sounds were prepared and the participants evaluated the "loudness," "pitch," "discomfort," and "tired feeling." In the sound quality analysis, multiple
regression analysis was applied to understand which sound factor affects largely to the discomfort and tired feeling. As a result, both "discomfort" and "tired feeling" were observed to be affected by "loudness" and "pitch." Especially, tired feeling
was found to be affected more by the pitch of the sound than that of discomfort. From these results, the noise at high frequency band was clarified to be necessary to improve the sound quality.
Flyover noise evaluation of low-noise technologies applied to a blended wing body aircraft
Authors: Legriffon Ingrid , Bertsch Lothar , Centracchio Francesco , Weintraub Daniel
Published: February 2023

In the frame of the European research project ARTEM (Aircraft noise Reduction Technologies and related Environmental iMpact), new aircraft architectures and alternative propulsion systems, e.g. Blended Wing Body (BWB) and geared turbofan engine concept, are investigated, as well as
innovative noise reduction technologies such as metamaterials and low noise high-lift device systems. A noise impact assessment has been performed on a long-haul BWB concept developed by Roma Tre University, using the System Noise Prediction Tools of ONERA (CARMEN) and DLR (PANAM). First,
shielding effects on the main noise sources are discussed, through installation effects hemi-spheres at chosen frequencies around the aircraft. Based on the shielding assessment, detailed take-off and landing procedures are simulated for several aircraft configurations. Two motorisations of
the BWB are evaluated (BPR 8 and BPR 12), provided by RWTH Aachen. Finally, the most promising low noise technologies developed in the frame of ARTEM are applied, and their impact on noise levels on the ground is discussed. It can be demonstrated how the specific aircraft configuration, the
engine type and the additional low-noise technology result in a significant overall noise reduction. A joint conference paper presents flyover auralisations based on these noise emission calculations.
Correlation Between Acoustic, Luminous, Thermal Dimensions of A Urban Park In an Oasis Settlement and emotional response of Visually Impaired Users
Authors: Boucherit Samiha , Masullo Massimiliano , Berkouk Djihed , Maffei Luigi
Published: February 2023

Occupants' interaction with urban spaces and their behavior is often influenced by environmental dimensions: thermal, visual, acoustic or air quality. Many studies have investigated the relationships between occupants' behavior and these dimensions, but just few of them have addressed
occupants with special needs, such as the visually impaired. This study, based on measurements' campaign and research activities conducted at Biskra (Algeria) inside an urban park in an oasis settlement, provides further investigations about the relationship between acoustic, luminous, thermal
dimensions and the emotional response of visually impaired users as a basis for validating and improving their wellbeing in important spaces of the urban environment such as the public parks. The methodological approach is based on both quantitative and qualitative assessment. The objective
study is based on evaluating the physical dimensions of the site, while the subjective one is based on conducting in-situ questionnaires such as a multi-items Likert scale and multi-sensory evaluation towards the environment. Findings obtained from this study could offer a new vision to planners
and designers to improve the wellbeing of visually impaired users by including the multisensorial dimensions as constitutive elements of architectural, urban and environmental projects.
Inverse scheme for sound source identification in a vehicle trailer
Authors: Nowak Jonathan , Wehr Reinhard , Haider Manfred , Kaltenbacher Manfred
Published: February 2023

Tire/road noise is a highly relevant topic for improving the comfort and experience of drivers and residents living in high-traffic areas. With the growing numbers of electric cars, the relevance of tire noise even increases since it is the dominant sound source in the middle-speed
range. We investigate acoustic sources relevant to tire/road interactions. In doing so, we apply different sound source localization algorithms to measurement data acquired inside a large measurement trailer equipped with microphone arrays. The methods for sound source identification used
are well-known beamforming-based algorithms and inverse schemes based on finite element or boundary element simulations. The latter schemes require the identification of the acoustic properties of the trailer in the stationary case. In this contribution, we present the characterization process
and the results of the sound source localization in this stationary case.
Local authorities in The Netherlands supported by new software tooling in delivering European strategic noise maps
Authors: Lolkema Dorien , Greefhorst Danny , Skornsek Jan
Published: February 2023

The new reporting mechanism of the European Environmental Agency makes for uniform and standardized data exchange. It is an inevitable move in a world where environmental data needs not only to be available, but also accessible to all people. This change however, asks a lot of competent
authorities. All competent authorities must now alter their standard operating procedures when producing strategic noise maps and other reports. The Dutch government wants to support competent authorities in complying with this new reporting mechanism by developing software tooling. The tooling
is an extension of an already developed platform that supports the Dutch noise legislation rules. With this specialized tooling, competent authorities can upload a file with their strategic noise map. The tooling takes care of reprojecting to the required coordinate system and the validation
of the file to the information model of the new reporting mechanism. It also merges individual strategic noise maps to compose national strategic noise maps. In addition, the tooling takes care of publishing the according INSPIRE compliant services. In this presentation, we will show you how
this works, and how it fits in with national and European noise legislation. Finally, future perspectives of this development will be presented.
High sensitivity of indirect noise predictions in non-isentropic nozzles
Authors: Jain Animesh , Magri Luca
Published: February 2023

In aircraft engine combustors, incomplete mixing and air cooling give rise to flow inhomogeneities. When accelerated through the nozzle guide vane downstream of the combustor, these inhomogeneities give rise to acoustic waves. This is commonly known as indirect combustion noise. When
these sound waves are reflected off the outlet and travel upstream of the combustor, they can lead to thermoacoustic oscillations. To predict indirect noise, models proposed in the literature assume the frequency of impinging disturbances to be small (compact nozzle assumptions). However,
in reality, the assumption might not hold; hence, a mismatch in the predicted and experimental results can be observed. First, we present a semi-analytical solution to a non-isentropic nozzle indirect noise model using asymptotic expansion. Second, we show that the indirect noise predictions
are sensitive to a small change in the Helmholtz number for a nearly compact nozzle, especially in the subsonic flow regime. We also show the predictions become lesser sensitive as the non-isentropicity increases. This study highlights the importance of non-compact assumptions for the accurate
prediction of indirect noise transfer functions and thermoacoustic instability in aeronautical gas turbines.
Technical aspects of physical implementation of an active noise control system: challenges and opportunities
Authors: Anachkova Maja , Domazetovska Simona , Petreski Zlatko , Gavriloski Viktor
Published: February 2023

Active noise control systems have become a subject of intensive worldwide research that have aroused considerable interest as being a promising solution to the problem of low-frequency noise control. Advanced real-time signal processing technologies offer opportunities that have been
adopted in many active noise control industry applications, as well as in the modern urban environment where noise reduction is gaining priority status. Depending on the application, the concept of active sound control can be implemented using different control strategies. The development
and application of such systems requires in-depth knowledge and theoretical analysis in the field of digital signal processing, sensor technology, adaptive control, understanding in hardware solutions for acquisition and data processing, as well as software capabilities for modeling, visualization
and control of signals. Also, the construction of such a system must give an overview of the choice and characteristics of its components in terms of the impact of the elements that make it up on its accomplishment. This paper provides an insight into the engineering aspects for implementation
of an active noise control system in a duct, emphasizing all technical requirements that need to be analyzed and might further affect the systems overall performance.
Sound environment of bedrooms in typical long-term care facilities in China
Authors: Xie Mingxuan , Deng Zhixiao
Published: February 2023

Evidence shows that older individuals would be more sensitive to noise, whereas sound environment of healthcare facilities for seniors in China is largely ignored. In this study, acoustic measurements were carried out over 24 hours in twelve bedrooms in five typical long-term care facilities,
including two nursing homes and three adult homes in Kunming, China. Sound perception and preference of elder and nursing staff were also investigated through questionnaire surveys. The results showed that the noise levels of the measured bedrooms reached 47.4~59.3 dBA during the daytime and
39.1~49.3 dBA during the nighttime. The nursing homes were measured higher noise levels than the adult homes due to nursing care activities. Meanwhile, results showed a more significant gap between the bedrooms facing the streets and those not facing the streets. In terms of subjective evaluation,
'traffic noise' was the most common and unwanted noise source considered by both recipients and staff. Recipients from nursing homes indicated that noise has more significant impact on their 'sleep,' 'health' and 'relaxation' than those from adult homes. The indoor soundscape could be improved
by introducing some natural sounds such as 'stream,' 'birds,' 'wind' and 'rain' which were considered as the wanted sounds by most participants.
Physical Quantities Reconstruction in Reacting Flows with Deep Learning
Authors: Tathawadekar Nilam , Silva Camilo , Sitte Philip , Doan Nguyen Anh Khoa
Published: February 2023

Performing measurements in reacting flows is a challenging task due to the complexity of measuring all quantities of interest simultaneously or limitations in the optical access. To compensate for this, recent advances in deep learning have shown a strong potential in augmenting the
information content in datasets composed of partial measurements by reconstructing the quantities that could not be measured. The present work analyses the use of such deep learning tools for the reconstruction of quantities in two different cases. First, Convolutional Neural Networks (CNNs)
are used to reconstruct the heat release rate (HRR) from velocity measurements in a methane/air premixed flame under harmonic excitation. The CNNs are trained from complete datasets at some specific frequencies and amplitudes of excitation and their ablility to reconstruct the HRR for different
operating conditions with good accuracy is demonstrated. Secondly, an alternate approach based on Physics-Informed Neural Networks that do not require the training data to have all the quantities is explored. It is applied to a puffing pool fire where the velocity field is reconstructed from
observations of pressure, temperature and density with good accuracy. Both approaches are also shown to be robust with respect to noise.
Reduction of transmitted impact sound of dry-type floating floor due to differences in impact force characteristics
Authors: Tomita Ryuta
Published: February 2023

In Japan, JIS A 1418-2:2019 specifies the car-tire with impact force characteristics (1) and the rubber ball with impact force characteristics (2) as standard heavy impact sources. In addition, JIS A 1440-2:2007 specifies the measurement method of the reduction of transmitted impact
sound by floor coverings on a solid standard floor. It has also been reported that the reduction of transmitted impact sound differs depending on the impact sources of the car-tire and the rubber ball. It has been reported that one of the reasons for different reduction of transmitted impact
sound is excessive car-tire impact force, and a tendency for a nonlinear response to impact force for a dry-type floating floor. In this study, an experimental examination is conducted to interconvert the reduction of transmitted impact sound of the car-tire and the rubber ball. This paper
discusses the reduction of transmitted impact sound due to the change in impact force by varying the drop height of the car-tire and the rubber ball. The results suggest that the difference in reduction of transmitted impact sound between the car-tire and the rubber ball cannot be explained
only by nonlinearity due to the impact force for a dry-type floating floor.
The influence of audience participatory noise on sound levels at live events.
Authors: Kok Marcel , Hill Adam , Burton Jon , Mulder Jos
Published: February 2023

The 'audience verbal appreciation' for a worldwide known artist can raise the decibel levels during a show. This can lead to limit violations if there is a decibel limit for the show. In this publication the effect of a yelling audience, known by almost all sound engineers, will be
described. The research was done at 18 large live shows in Belgium and the Netherlands in the years 2015..2019. The measurement setup was a single channel measurement with a class 1 sound level meter at FOH. The data was stored as LAeq,1sec and LCeq,1seq and also the 1/3 octave band information
per second was logged. The outcome gives more information about the frequencies of yelling, but more important the effect on the decibel level of the total show. Besides measuring at FOH (front-of-house) position, two alternative measurement methods are discussed (2-channel setup and multiple
measurement points in the hall).
Principle dimensions of perceptual attributes in indoor public spaces
Authors: Yilmazer Semiha , Acun Volkan , Dalirnaghadeh Donya , Fasllija Ela , Şahin Zekiye , Mercan Elif
Published: February 2023

This study aims to analyze the principal dimensions of perceptual attributes in indoor public spaces. Healthcare, working, cultural, educational, leisure, worship, and transportation spaces (e.g., bus, train, metro stations, and airports) were chosen as public spaces. Three members
of the research team independently listened to all 70 binaural recordings, taken from indoor spaces, and for each recording identified whether human-generated sounds (e.g., conversation, laughter, footsteps, and coughing), technology-related sounds (e.g., mechanical and electronic sounds)
and/or environmental sounds dominated. University students (n=120) performed a listening test to assess 70 binaural recordings of indoor soundscapes on users' attribute scale. Principal component analysis shows that there are two prominent groups: pleasantness and eventfulness. Perceived sound
environments dominated by technology-related sounds were found to be unpleasant, while the acoustic environments dominated by human-generated sounds were eventful.
The new aircraft noise monitoring system introduced at the three airports in the Osaka area
Authors: Izumi Junshi , Nishino Yoshio , Matsubara Kenji , Izumi Jyunshi , Fujita Etsushi , Higashioka Taichi
Published: February 2023

There are three airports in the Osaka area and each of them has been analyzing and evaluating aircraft noise and publishing its results. However, since these three airports are adjacent to each other, the airspace is complicated, and the monitoring range is wide, which caused so much
manual work for data review before obtaining an accurate noise impact assessment. This paper introduces a new aircraft noise monitoring system that has been constructed to reduce the human workload and accurately and integrally monitor aircraft noise at the three airports with flight-track
measurement. The new system reduces the time for noise analysis and evaluation using artificial intelligence, and it has become possible to publish accurate noise conditions more quickly and at a lower cost. In addition, since it is difficult for an airport operator to obtain air traffic control
data, we constructed a system that can monitor the position coordinates of aircraft as recent as 15 seconds ago. By operating this system integrally with the noise system, we can now visually confirm the noise level at the measurement point and the position of aircraft on a map, and publish
the real-time noise data online for residents living near the airports.
Noise reduction by perforated cascades in annular ducts
Authors: Shen Zihan , Wang Xiaoyu , Sun Xiaofeng
Published: February 2023

One of the latest trends in noise control relating to aeroacoustics is to mimic the silent flight capability of owls. Particularly, porosity is most often applied on cascades in ducts with axial flows, such as stator structures in an aero-engine. However, current acoustic scattering
models of perforated cascades are based on two-dimensional methods without including the three-dimensional effects. In this paper, we present a fully three-dimensional acoustic scattering model for perforated cascades based on the lifting surface theory in which the dominant sound source reduces
to dipoles alone under the thin airfoil assumption. Accordingly, the acoustic scattering of perforated cascades with single-mode incident wave was studied and obvious noise reduction was observed. The optimum Rayleigh conductivity and the maximum noise-reducing capability of the porosity varied
substantially with different incident duct modes, whilst a larger cascade chord-length could achieve more noise reduction at optimum porosity. With a background flow, the Kutta condition can greatly influence the overall distribution of the unsteady loading on vanes. Additionally, the unsteady
vortex shedding at the trailing edge offers extra sound energy dissipation mechanism. Therefore, the implementation of porosity on cascades is much different to the design of a traditional acoustic liner.
Speech privacy through dynamic fundamental frequency matching
Authors: Lo Charlene , Hui C. T. Justine , Hioka Yusuke
Published: February 2023

The lack of speech privacy is known to be detrimental to one's physical and psychological health. When physical barriers are not feasible to provide this, a masking noise may be implemented to provide speech privacy. Such maskers are most effective when the difference in mean fundamental
frequency (F0) between speech and the masker is minimised. Furthermore, noise annoyance is primarily attributed to the loudness and presence of high-pitched components. The present study investigates the effectiveness and annoyance caused by a masker that minimises instantaneous F0 differences.
Two seed maskers (pink and babble noise) were used to generate a unique masker for each test sentence read by a variety of speakers. A subjective listening test and annoyance survey were carried out to determine the effects of the dynamically matched masker, a stationary masker at the mean
fundamental frequency of each speaker, and the seed masker without F0 processing. The maskers were played at a variety of target to masker ratios. Preliminary results show that the dynamically matched masker is as effective and less annoying than the stationary masker.
Equivalent Circuit Method Based Double Layer Micro-perforated Panel (MPP) Design to Widen the Sound Absorption Bandwidth
Authors: Fasllija Ela , Yilmazer Semiha , Yilmazer Cengiz
Published: February 2023

Acoustical solutions that occupy minimum space and simultaneously allow for flexibility in interior spaces are not feasible by using thick absorbers like conventional porous and fibrous materials. Micro-perforated panels are an excellent alternative to those classical materials due
to their environmental friendliness, design flexibility on various materials, and easy installation. However, they come with the handicap of having a very narrow absorption frequency bandwidth. This study explores two inhomogeneous microperforated layers arranged in a cascade with different
back cavities in order to widen the sound absorption bandwidth. This serial-parallel architected MPP system is investigated by mathematical models using Maa's model for a single MPP and the Equivalent Circuit Method (ECM). The numerical results were validated through experiments for normal
sound incidence in the impedance tube using the transfer function method. Increasing the back cavity length of the MPP having a higher perforation ratio and larger holes results in a higher absorption in the high-frequency range. In contrast, combinations of larger cavity lengths and smaller
perforation ratios are more effective in the low-frequency spectrum. By tuning the design parameters of those structures, it is possible to achieve wideband absorption by fibreless materials for room acoustic applications.