bluuebunny/crossref_metadata_2025 huggingface dataset:
Psychophysics based on sensation level of older adults by self-experiments at home: A case study
Authors: Kuwano Sonoko , Namba Seiichiro , Kaku Jiro , Yamada Ichiro
Published: December 2023

Older adults have many difficulties in hearing such as the difficulty in listening to speech under reverberant and/or background noise, the decrease of time resolution as well as the decrease of hearing level in high frequency region. The individual difference is also large. If the
information related to the individual difference can be obtained, it would be significant to know the listening world of impaired listeners. There are many problems to invite older adults to visit laboratory for the experiments even in non-COVID-19 situations. In this study, it was tried to
measure the sensation levels of older adults in the experiments at their homes using headphones. As the results, high correlation was found between the sensation level and the loudness by doing self-experiments. Gap detection as an index of temporal resolution was also examined. Further experiments
are planned using Python to design the response panel and experimental procedures.
Using hydrophone measurements to monitor incipient cavitation in variable displacement pendulum-slider pumps
Authors: Battarra Mattia , Natali Caterina , Gambetti Davide , Blum Alessandro , Mucchi Emiliano
Published: December 2023

The present work proposes an experimental methodology for monitoring the inception and the subsequent development of cavitation and aeration in variable displacement pendulum-slider pumps. These two phenomena may affect volumetric machines when the working condition requires high values
of working speed and specific displacement, often causing undesired broadband noise. Since these pumps find their most common application in automotive auxiliary systems and powertrain lubricating circuits, the abnormal noise caused by this phenomenon is often unacceptable. Based on these
considerations, an experimental cavitation detection method based on hydrophone measurements is proposed and assessed through direct comparison with a non-cavitating machine. Cavitation is promoted by increasing the pump working speed, as it happens in actual automotive applications. The effective
presence of cavitation is further checked with the help of durability tests and efficiency measurements, made possible by the capability to control the pump working eccentricity. Measurements are repeated for different values of both specific flow rate and oil temperature, showing that these
operational parameters have a consistent interaction in the definition of the inception of the phenomenon and its intensity.
Radiation mode-based personal audio system: Robustness against wall reflection
Authors: Higashikawa Akira , Uchida Yoshiteru , Sasajima Manabu , Kaizuka Tsutomu
Published: December 2023

Confining sounds in the near field of a loudspeaker array is discussed for realizing personal audio systems. Active acoustic power propagates to the far field, whereas reactive acoustic power does not. Therefore, increasing the ratio of the reactive acoustic power to the active acoustic
power leads to acoustic confinement in the near field. The reactive-to-active ratio is maximized by optimally driving loudspeakers. The optimal driving signals are derived based on the theory of generalized radiation modes. This method was proposed in earlier studies by the authors. In the
literatures, point acoustic sources on an infinite baffle were assumed to be in a free space, and the radiation mode theory was applied to obtain the optimal driving signals. However, in practice, walls may exist nearby the loudspeaker array. Acoustic waves radiating from the loudspeakers
are reflected by the walls. Such a wall reflection may degrade the acoustic confinement. In this study, the robustness against a wall reflection is investigated.
Stochastic modeling of porous sound absorbing materials using homogenization method and machine learning
Authors: Komatsu Yosuke , Yamamoto Takashi
Published: December 2023

This research introduces a novel approach to investigate porous sound absorbing materials using stochastic modeling techniques. The study employs the homogenization method and machine learning to predict the acoustic properties of porous materials. The homogenization method simplifies
the analysis of microstructural properties in porous materials, while machine learning is a data analysis technique that utilizes algorithms to learn from data and make predictions. By integrating these methods, this study quantitatively assesses the impact of microscopic structural randomness
on sound absorption properties. The study assumes that microstructural parameters are random variables and calculates the sound absorption coefficient through homogenization method. This dataset serves as input for machine learning. A Gaussian process regression model is developed using the
dataset to evaluate the distribution of the sound absorption coefficient via the Gauss-Hermite quadrature method. The study implements Bayesian optimization, utilizing the variance of the resulting probability distribution as the acquisition function, to adaptively update the dataset. By iteratively
performing these processes, the probability distribution of the sound absorption coefficient can be predicted efficiently and with high accuracy.
Performance of speech enhancement algorithms on the speech intelligibility of native Mandarin listeners immersed in English-speaking environment
Authors: Zhang Yunqi C. , Hioka Yusuke , Hui C. T. Justine , Watson Catherine I.
Published: December 2023

Speech enhancement algorithms have been developed to improve speech intelligibility for listeners under noisy conditions. However, all existing algorithms were evaluated only by native listeners, the performance of such algorithms on non-native listeners was rarely investigated. This
study conducts a subjective listening test on native New Zealand English listeners and native Mandarin listeners who have been immersed in New Zealand English-speaking environment for more than one year. The participants were asked to transcribe noisy English sentences processed by five widely
used single-channel speech enhancement algorithms. The speech intelligibility of the two groups was quantified and compared to investigate the effectiveness of the speech enhancement algorithms on non-native listeners who are familiar with the target language.
On the use of a tailored fluid-fluid Green's function to predict scattering from two-phase fluid interfaces
Authors: Pacaut Louise , Serre Gilles , Mercier Jean-François , Chaillat Stéphanie
Published: December 2023

In naval applications, the precise knowledge of the acoustical behaviour of two-phase fluids is of interest. Indeed, they appear in many configurations as bubbles curtains, cavitation (along propellers and pipes) or two-phase turbulent boundary layers and wakes (gas exhaust). To model
this problem, we focus on a Boundary Element/ Boundary Element coupling for low to moderate frequencies. We propose two approaches: (a) solving the Helmholtz equations in each phase by introducing the free field Green's function and (b) determining a tailored Green's function, taking into
account the presence of the two-phase fluid. The determination of a tailored Green's function has two main advantages: (i) it allows a reduction of the numerical model, since it contains all the information on the fluid-fluid coupling, in particular the transmission conditions and resonances
and (ii) it is source-independent and thus it gives directly the answer to any source. Numerical tests on the evaluation of radiated noise are performed to determine the efficiency of the approach based on a tailored Green's function compared to the free-field based one.
Experimental study on the relationship between combustion and noise and vibration in a gasoline engine
Authors: Sato Hironao , Oba Masahiro , Hiromoto Takashi , Sato Kiyofumi , Sonobe Toshiyuki , Hayakawa Satoru , Morikawa Koji , Moriyoshi Yasuo , Sekine Noriaki
Published: December 2023

An experimental study was conducted to clarify the relationship between engine combustion and noise and vibration, and concerning design indexing for its suppression. This study focused on the vehicle interior noise caused by combustion in which vibration transmission is the main component
at high speed and high load region. A phenomenon in which both the combustion's exciting force and the structure's exciting force are combined is defined as vehicle interior noise caused by combustion. Conventionally, combustion and noise and vibration are often discussed in terms of the average
cycle, but considering the nonstationary property of noise and vibration, in this paper analyzed the characteristics of both exciting force for vibration in cycle-by-cycle based on clustering analysis. The engine vibration is affected by heat release characteristics even with the same engine
structure specifications. The heat release characteristics were determined as indicators for the combustion's exciting force. The engine vibration is affected by piston specifications even with the same heat release characteristics. The piston tilt and translational displacement were determined
as indicators of the structure's exciting force. This paper clarifies the influence of each exciting force on vibration and discusses indexing that contributes to design.
Assessing the low-frequency measurement procedure for the measurement of impact sound insulation using the rubber ball
Authors: Hirakawa Susumu , Hopkins Carl
Published: December 2023

ISO 16283-2 includes a procedure for measuring field impact sound insulation at low frequencies using a tapping machine to improve the repeatability, reproducibility, and relevance of results in the 50, 63, and 80 Hz one-third octave bands in small receiving rooms (volumes less than
25 m3). However, the low-frequency measurement procedure with excitation from a standardized rubber ball was not included because the link between measurements of Li,Fmax from the central region and corners had not been established at the time of writing. This paper assesses the use of the
low-frequency measurement procedure with a rubber ball source through measurements of Li,Fmax in a vertical transmission suite at the Building Research Institute (Japan). It also provides analysis of the modal sound field in the receiving room due to rubber ball excitation of the concrete
slab. The results indicated that the low-frequency measurement procedure was beneficial in this 60 m3 room to estimate the room average sound pressure level below 80 Hz. Future work could therefore evaluate the low-frequency procedure in the field with different room volumes and floor constructions.
Ecoflight Monitoring - new aircraft noise monitoring system with neural network-based data filtering
Authors: Kartyshev Mikhail
Published: December 2023

Reliable measurements and further evaluation of noise environment in the field, as well as refinement of an airfield noise zone are directly impacted by the completeness and accuracy of registered individual noise events created by aircrafts flying near monitoring locations. Also, monitoring
stations are often located in densely-populated areas that feature other noise sources. Detecting aircraft flight events becomes even more complicated when there is no location data for aircrafts that lack ADS-B transponders. The Moscow region, where most aircraft noise monitoring projects
are run, is unique in that there are 8 closely located airfields used both for regular passenger flights and flights of experimental aircrafts not equipped with transponders. Each of the 50 noise monitoring stations can simultaneously register noise events that correspond to flight of aircrafts
at different airfields. Aircraft flyover events were detected on the noise time line using an artificial neural network (ANN) that allows to identify aircraft audibility periods at the monitoring location using the 1/3 octave band of noise registered in real time for all measurement locations.
This article describes the development of an ANN architecture based on the YOLO v4 convolutional neural network, as well as requirements and mechanisms for normalizing data fed to the ANN that filters data provided by the Ecoflight Monitoring aircraft noise monitoring system.
Impact of aircraft deviations from the standard trajectories in the vertical and horizontal planes on generated noise
Authors: Igor Ardashev
Published: December 2023

This article analyzes the effect of changes in aircraft spatial positions on noise impact at the ground level. The research used the Ecoflight Monitoring noise monitoring system to analyze 2,005 flight trajectories and corresponding noise events related to aircraft flyovers. It also
shows the effects on noise levels registered at certain positions of changes in climb and descent parameters and distribution of lateral deviations relative to the expected AIP aircraft trajectory. A comparative analysis of calculated and experimentally established parameters shows the necessity
to take into account the influence of actual flight trajectories distribution on the noise environment. Modeling the noise contour confirms the need to use actual information about flight paths and profiles of aircraft collected with noise monitoring system to get the most approximate result
to real conditions. The developed software system for determining and monitoring the aircraft flight corridor enables effective management and control of the noise zone in the vicinity of the airport.
Bayesian inference for the interior noise problem of railway vehicles
Authors: Muto Daisuke , Yoshizawa Takashi , Sato Wataru
Published: December 2023

Design and control of interior noise of transportation systems, such as rollingstock, is important from the standpoint of comfort. Therefore, a technical field called "NVH" has been established and various noise reduction methods have been developed. On the other hand, noise
reduction measures conflict with other performances such as weight reduction and space saving. In many cases, there is a large uncertainty in the causal relationship between noise control measures and their effects. Therefore, the conventional deterministic method leads to designing on the
overly safe side for achieving the noise target value, which is not desirable from the viewpoint of other performance. One solution to these problems is the introduction of probabilistic design decision making, which is used in such as the evaluation of the seismic resistance of nuclear power
plants and the reliability of bearings. The authors have developed a Bayesian inference method for estimating the transfer function level , and contribution of noise source type, with the aim of introducing probabilistic decision making into interior noise design. The estimation accuracy was
verified by applying the method to artificially generated data. As a result, it was confirmed that the estimation was possible at a practical level.
Instantaneous Structural Intensity Analysis on Vehicle Body
Authors: Abe Keisuke , Tanaka Yunosuke , Yamazaki Toru
Published: December 2023

This paper is a study of analysis techniques for the generation mechanism of panel vibration based on vibration energy propagation. First, the propagation path of the traveling wave in the entire system was visualized by instantaneous structural intensity analysis using FEM, which enabled
the identification of effective areas for reducing panel vibration. This technique was further applied to a vehicle body model. Based on the propagation paths of the traveling waves, the panels that contribute to the sound can be identified, and it is shown that controlling the paths with
the intention of not transmitting them to the cabin is effective in reducing panel vibration and interior noise.
Speech Signal Extraction Method Based on Bayesian Estimation Using Air- and Bone-Conduction Sound in Speech Confusion
Authors: Tamura Yukina , Orimoto Hisako , Ikuta Akira
Published: December 2023

With the recent development of digital information technology, speech information recognition system has improved dramatically and is being applied in a wide range of fields. In order to improve the system efficiency, countermeasures measures against noise from the surrounding environment
have become an important issue. In the previous study, we derived an algorithm to estimate speech signals by using air-conducted speech signal mixed with noise as observation and bone-conducted speech signal. In this research, we propose an algorithm to obtain more accurate estimation results
by using not only air-conducted speech signal mixed with noise but also bone-conducted speech signal as observation values. The effectiveness of the proposed method was confirmed experimentally by applying it to mixed speech signals actually measured in surrounding noisy environment.
Efficiency testing of active noise control in the duct outlet and effect of the error microphone location
Authors: Lesoinne Stéphane
Published: December 2023

In a duct, the performance of the active control system depends among other things on the position of the loudspeaker. In ventilation systems, they are usually inserted in the ductwork along the duct wall or in the duct if its diameter is large enough not to generate too much pressure
drop. In this paper, we describe an active noise control system placed not in the duct but at its outlet, instead of the ventilation grille. The control loudspeaker being no longer in the duct, it must remain close enough to the outlet to "colocalize" the two sources of sound waves
(ventilation noise and control) and keep a global noise control while leaving a sufficiently large opening to allow a similar ventilation flow obtained with a standard ventilation mouth. The error microphone is placed outside the duct and the influence of its position is also analyzed on a
ventilation system prototype. The obtained attenuation is good and extends over a wider range of frequencies than when the loudspeaker is placed at the periphery of the duct. Moreover, its position at the outlet of the duct is better for using the speaker as a source of sound diffusion.
Enhancing acoustic contrast in multi-zone sound field reproduction through optimization of loudspeaker arrangements
Authors: Zhou Tong , Yasueda Kazuya , Kataoka Akitoshi
Published: December 2023

In this study, we propose a stepwise-based approach, predefined in descending order of source power, to optimize loudspeaker placement in multi-zone sound field reproduction systems. The aim is to enhance the acoustic contrast (AC) between acoustically bright and dark zones. The proposed
method is benchmarked against two previously studied approaches: the Genetic Algorithm (GA) and the Greedy-based approach. Numerical simulations are conducted to evaluate and compare the performance of each method. Results demonstrate that the proposed method surpasses the Greedy-based approach
in terms of AC, while offering performance comparable to the GA-based approach. Importantly, the proposed method exhibits lower computational complexity than the GA, suggesting a more practical solution for real-world applications.
Verification and application of the aircraft noise simulation framework J-FRAIN
Authors: Kobayashi Tomohiro , Yokota Takatoshi , Makino Koichi , Ikuta Yuho , Imamura Taro , Takaishi Takehisa , Kawase Yasuaki
Published: December 2023

We newly developed a framework for aircraft noise simulation, J-FRAIN, that can precisely predict the noise from aircraft at ground observation points during the landing approach phase. J-FRAIN enables the incorporation of component-wise regression sound source models created from field
measurement data using a microphone array system and the precise prediction of the time history of noise from each aircraft component. To verify the noise prediction accuracy of J-FRAIN, noise prediction of the landing approach phase around an airport was performed. The component-wise regression
sound source models created from the data measured at the location just before touch-down was used since its regression model can estimate the sound power levels at flight parameters not only actually measured but also not measured. The predicted result and noise measured by aircraft noise
monitoring systems were verified to be in good agreement. As examples of the application using J-FRAIN, two case studies were also discussed; the determination of the contribution of each noise source at observation points and the evaluation of the influence of flight parameter differences
on noise levels at observation points.
Effect of large bus body reflection on sound barrier efficiency for road traffic noise control: a simulation study
Authors: Zhang Jiping , Luo Qingdong , Zhu Hong , Zhang Yong
Published: December 2023

Assessment of road traffic noise (RTN) generally approximates vehicles as point sources, including in the setting of roadside sound barriers (SBs). However, when a large passenger bus passes on a road section with an SB, strong reflected sound waves emerge between the bus body and the
SB, reducing the effectiveness of the SB. In this study CadnaA software was used for simulating the sound field distribution formed by such reflections. Because a large bus cannot be approximated as a point source, multi-point noise measurement results of the near-field position of the body
of a moving bus were adopted for simulating the actual three-dimensional bus by distributing small-area sources approximately at the near-field different positions near the bus body surface. For a bus moving on a road past an SB, noise distributions were simulated for three scenarios: 1) without
an SB, 2) with a smooth reflection-type SB, and 3) with an absorption-type SB. This study presents important insights for establishing RTN SBs.
Automotive disc-brake squeal noise modeling for shape optimization under uncertainties
Authors: Jacquemond Achille , Besset Sébastien , Shimoyama Koji , Gillot Frédéric
Published: December 2023

Disc-brake systems in automotive vehicles tend to exhibit undesirable squeal noise during braking operations. Although this noise does not affect braking efficiency, it creates noise pollution and poses problems from a sales point of view since noise is commonly associated with malfunction
by consumers. Squeal noise can be minimized by optimizing the shape of the system's mechanical parts. However, uncertainties related to manufacturing processes inevitably affect the system's response, and must be considered. The presented work aims at numerically quantifying and minimizing
disc-brake squeal noise in the presence of uncertain parameters. A simplified disc-brake model is constructed using the novel Isogeometric Analysis method which is well-suited to shape optimization problems. The prediction of squeal noise propensity is based on the fact that squeal noise is
directly related to unstable structural modes and uses Complex Eigenvalue Analysis to determine the extent of squeal occurrences. A surrogate-based optimization strategy is used to handle the high computational cost in the context of optimization, as well as to propagate uncertainties. The
constructed model shows good capability for representation and quantification of squeal noise phenomena. A Pareto front of robust squeal minimizing shapes is obtained through the proposed approach.
A study on the application of road traffic noise map in Japan through the case of Osaka
Authors: Atobe Satoshi , Saito Yoshinori , Harada Kazunori , Oshima Takuya , Yamashiro Yudai , Hiraguri Yasuhiro
Published: December 2023

In this study, application of noise map for the prediction and examination of road traffic noise is discussed for two urban areas in Osaka Prefecture, i.e. Tennoji Ward (Osaka City) and Higashiosaka City. Noise mapping is performed based on the 2015 road traffic census data of Ministry
of Land, Infrastructure, Transport and Tourism (MLIT) by employing ASJ RTN-Model 2018, which is a model developed by the Acoustical Society of Japan (ASJ) for predicting the road traffic noise (RTN). For calculating the noise attenuation due to buildings, building façades are extracted
from the national base map of MLIT. To examine the effect of measures related to noise mitigation, noise maps are produced for several hypothetical cases, such as reduction of vehicle noise, adoption of porous asphalt pavement, and utilization of the speed limit for vehicle speed data.
Classroom Transformation for Better Education: Part 1 - A Systematic Review
Authors: Din Nazli Che , Razali Abdul Wafi , Yahya Musli Nizam , Sulaiman Raha , Razak Asrul Sani Abdul
Published: December 2023

In order to accommodate the teaching and learning process, various communication quality between educators and students in a classroom is necessary. Numerous studies have found that classroom acoustic comfort has an impact on both student performance and educator well-being. Several
factors influence a classroom's acoustic performance, including material selection, volume, noise disturbance, occupancy, and others. The purpose of this study is to critically review the significant design factors that influence a classroom's acoustic performance, including an in-depth discussion
of how the factors manipulate the classroom's acoustic parameters. As a result, the reviewed findings will be presented to demonstrate the relationship between classroom factors and acoustic parameters, and a conceptual framework for classroom acoustic comfort will be proposed as a guideline
for designers to use in the future.
Assessment of Noise and Vibration Annoyance and Other Physical Factors of Working Conditions on Vessels by Means Surveys - a Research Method
Authors: Pleban Dariusz , Kowalski Piotr , Zajac Jacek
Published: December 2023

Factors related to the working environment (e.g. excessive noise and vibration, inadequate lighting, excessive non-ionizing radiation) contribute to neglect in the work of vessel crew, while also causing health effects in their body. Fishing and shipping are among the sectors of the
economy that are characterized by particularly adverse working conditions. According to data published in 2021, among fishermen, of whom there are a total of about 28 million worldwide, about 24,000 of them lose their lives in the course of their profession every year. Many of marine accidents
on ships are caused by crew errors due to inadequate working conditions. Therefore, an comprehensive assessment of factors occurring in this specific working environment will be carried out. This assessment will include both those physical factors whose impact is generally considered to be
of great concern, such as noise, mechanical vibration or lighting, but also others, such as changing climatic conditions or psychosocial working conditions, which also have a significant impact on the well-being and ability to work and the safety and health of workers, including their quality
of life. The assessment will be based on surveys. The paper presents the description of the elaborated questionnaire due to noise and vibration.
Study on vibration measurement and sensory evaluation of combined vibration for detached houses
Authors: Matsuda Toru , Tomita Ryuta
Published: December 2023

Sensory and psychological content accounts for 90% of all vibration complaints in Japan. Therefore, evaluation based on vibration sensation is very important. Traffic vibration is the most common source of vibration that causes complaints, when limited to detached houses. If traffic
vibration is the source of complaints, occupants will suffer from vibration for a long period of time. Vibration transmitted by traffic to housing floors may not be either vertical or horizontal, but rather a combination of both vertical and horizontal vibration that exceed perceptual thresholds.
Japanese standards include "JIS C 1510" and "AIJES-V0001-2018". However, they do not describe methods for sensory evaluation of combined vibration. Although ISO 2631 series describes it, it is necessary to consider whether it can be applied to Japan as it is. Considering
that traffic networks will continue to develop in Japan, especially in urban areas, it is assumed that the vibration generated inside houses, mainly from traffic vibration sources, will not be a single vibration of vertical or horizontal vibration, but a combined vibration that is perceived
in multiple directions. Therefore, in this paper, vibration measurement and sensory evaluation of combined vibration were examined using a real house vibrated by traffic.
Psychoacoustic evaluation of the combined noise from devices in dental clinics
Authors: Yamada Tomomi , Hayashi Mikako , Nozaki Kazunori , Kuwano Sonoko
Published: December 2023

Quietness is required in medical facilities, however, dental clinics are often filled with various sounds. Especially after the Covid-19 pandemic, the noise level in dental clinics seems to have increased. There are not only the sounds of equipment such as dental drills and ultrasonic
drills for removing tartar but also sounds of air purifiers or extra-oral suction devices, music, and the sounds of the receptionist's phone, and the sound through doors and windows opened for ventilation. When various sounds are mixed, sometimes patients and staff cannot hear sounds during
treatment. We have investigated the psychoacoustic effects of complex noise emitted from equipment in a dental office. We will report on the relationship between psychological evaluation and physical values such as noise level and the ratio of frequency components and try to find the factors
for making a comfortable environment in dental clinics.
Recent research advances on high-speed railway noise
Authors: Sheng Xiaozhen , He Yuan
Published: December 2023

Around 42,000 km high-speed railways are in operation in China at speeds up to 350 km/h. 400 km/h trains are also under development. Huge resources have been put into research on high-speed railway noise. This paper outlines advances achieved in several key projects by covering the
following aspects: measurement results showing typical characteristics of high-speed railway noise; analyses on source contribution to pass-by noise based microphone array data; modelling of high-speed rolling, aerodynamic and viaduct bridge noise; prediction of the vibro-acoustic behaviour
of car-body with poro-elastic media; and finally, analyses of vibration transmission in the suspension/bogie system.
A Pilot Study on the Environmental Noise of Transit Oriented Development (TOD) Projects in Chongqing, China
Authors: Wongso Elsa Nalita , Xie Hui
Published: December 2023

Noise is still a significant problem in urban areas that requires attention. Within the past ten years, urban development has moved to the TOD concept, mainly a mixed-use, high-density, and compact public transportation-oriented area with commercial and residential areas. Due to more
functions in the area, the noise is expected to be higher. Despite this, research on environmental noise in the TOD area is still limited. This study will investigate the environmental noise in the outdoor areas of the TOD projects in Chongqing, China, namely U Cheng Paradise Walk and Gaoxin
Paradise Walk. This study used a questionnaire as the preliminary study and field measurement to know the existing conditions. Based on the questionnaire survey and sound level measurement, the TOD projects are relatively noisy in the 65-68 dBA range. This result exceeds the noise limit of
60 dBA the Chinese government gave in GB 3096-2008 for mixed-use areas. Noise barrier installation and additional natural sounds can be two of several solutions to improve the existing sound condition in the TOD projects. Further research related to the sound environment of the TOD projects
is needed to improve the sound environment quality. Keywords: environmental noise, transit oriented development, outdoor areas, noise limit
Sound absorption of resonators or perforated panels with multiple folded long tubes crammed in small module by additive manufacturing
Authors: Nakanishi Shinsuke
Published: December 2023

Resonators or perforated panels give a large sound absorption at a resonant frequency tuned by opening area of the pores, neck length and a cavity depth behind the neck. The author has studied the sound absorption of thin tile-like resonators tuned at low frequencies by including a
folded long neck in its surface panel. The resonators are made by an additive manufacturing with a fused deposition modeling (FDM). This paper makes the resonators or the perforated panels with multiple folded long tubes and discusses its measured sound absorption characteristics. One of the
multiple folded long tubes is crammed in 12 mm × 12 mm × 19.2 mm of rectangular module even if the tube has 2 mm × 2 mm of opening area and 288 mm of length. A perforated panel consisted of planar periodic arrays of this module gives a large sound absorption at 69 Hz when
a 40 mm depth of cavity behind the perforated panel. Furthermore, when the planar periodic arrays of small Helmholtz resonators applied single module and single cavity tuned at different resonant frequency, it has potential to form an acoustic metasurface with sound absorption at broadband
frequencies.
Reconfigurable sonic crystals with built-in Helmholtz's resonators for noise mitigation
Authors: Lee Heow Pueh
Published: December 2023

Natural ventilation is desirable for improving the air quality against airborne transmission of viruses. On the other hand, a good noise barrier would not have any opening for effective noise mitigation as noise can enter the space with the natural ventilation. The use of noise shields
and noise barriers for shielding a piece of noisy machine may also drastically cut down the natural ventilation which will be required for preventing heat built-up in the engine room. In this paper, acoustic metamaterials in the form of sonic crystals with built-in Helmholtz's resonators are
designed for targeting the mitigation of mid to low frequency noise. The designs can be made reconfigurable with different distribution of sonic crystal elements. These sonic crystals are designed to target noise of different frequencies and also to provide sufficient structural support for
large scale implementation. The designs can be used for providing a quieter corner for the occupants within a noisy environment, or to confine the noise from a machine or process within the sonic crystals.
Sound insulation performances of the wall profiles using autoclaved lightweight concrete block
Authors: Ahn Ok-Cheol , Kim Yong-Hee , Kee Seong-Hoon
Published: December 2023

This study aimed to predict the sound insulation performance of wall profiles made of autoclaved lightweight concrete (ALC) blocks using computer simulations. The single wall structures made of ALC were evaluated based on variations in density and thickness, with densities ranging from
0.3 g/cm³ to 1.2 g/cm³ and thicknesses from 20 mm to 350 mm. The results showed that there was a reduction in sound insulation performance between 200 Hz and 400 Hz due to the coincident effects of ALC materials. Although increasing density and thickness could have improved sound
insulation, the overall performance did not meet legal standards. The study then explored the effect of composite structures, which incorporated reinforcing materials in the ALC blocks, and found that the sound insulation performance was improved by up to 5 dB compared to single structures.
The predicted results were verified through laboratory testing and measurement of the composite structures made of ALC.
Diffractors on a low screen: a valid alternative for conventional noise screens along multi lane motorways?
Authors: Goubert Luc
Published: December 2023

Diffractors are an innovative way of shielding noise from e.g. motorways by bending the propagation direction of sound waves upwards and hence creating an acoustic shadow area along the road. The bending upwards is done by the interaction of the road noise with a series of slits, all
parallel to the road but with varying depths for varying resonance frequencies. This principle has been invented about 10 years ago and has since then been tested with temporary and permanent constructions. The slits can be integrated in the ground, but can also be put on a low (0,5 - 1 m)
screen for enhancing the performance at short distance. The Belgian Road Research Centre has carried out several measurement campaigns at different diffractor set ups on low screens. The measurements were of the "Controlled Pass-By" type yielding consistent results. An overview is
given of the findings since the first measurement, including the new results obtained along a ring road in the Dutch town of Amersfoort in 2022, where for the first time such a device was constructed along a 2 x 2 lane, showing the performance in case the noise source is at a larger distance
from the diffractor.
Introducing ICBEN's new socio-acoustic survey archive ISAR
Authors: Brink Mark , Nguyen Thu Lan , Schreckenberg Dirk , Wothge Jördis
Published: December 2023

The International Committee on Biological Effects of Noise (ICBEN) has recently started an international archive of original survey response data from so called socio-acoustic noise surveys, named ISAR (ICBEN Socio-Acoustic Survey Archive). The ISAR archive caters to noise effects researchers
around the globe and enables pooled analyses, establishment of generalized exposure-response relationships, trend analyses both spatially and temporally, as well as cross-cultural comparisons of self-reported noise reactions (noise annoyance and noise-induced sleep disturbances in particular).
The data in the archive will be freely accessible. Data in the ISAR archive are fully anonymous in order to meet the pertinent data protection regulations in most countries. The ISAR archive is curated by ICBENs officers and the team chairs of Team 6 (Community response to noise and annoyance).
The ISAR archive explicitly collects only raw survey response data, rather than data that have been aggregated on a higher level. We are constantly seeking to extend the archive with new study data and thus, every new contribution is highly welcome. In this talk, we would like to publicize
and promote the archive and encourage our colleagues to share their survey data with the archive.
Newly proposed Swiss transportation noise limits in comparison with recent WHO recommendations
Authors: Brink Mark , Wunderli Jean-Marc
Published: December 2023

In December 2021, the Federal Noise Abatement Commission, a counseling committee of the Swiss government, has proposed new noise limits for road, rail and air traffic that overall are considerably stronger than the values that are currently in force. For the day period, the recommended
limits for road traffic noise remain the same, but are about 6 dB lower than before in the case of railway and aircraft noise. For the nighttime, the recommended values are about 1 to 3 dB stronger than the current limits. Despite this tightening, the desired new Swiss noise limits are still
less stringent than the seminal WHO recommendations from 2018. Aside from juxtapositioning the Swiss versus WHO limits, we explain that such differences are not only due to different conceptions and legal demands regarding the protection of health, but also due to different legal implications
that are triggered if limit values are exceeded. The WHO limits can be seen as general recommendations for rather long-term policy goals, whereas the Swiss limit values only protect against "significant" disturbances of health and well-being in a rather short-term context of current
political feasibility. Comparing noise regulations using limit values given in decibels alone remains a difficult issue.
A study of 3D FEM traffic vibration simulator and comparison with INCE/J RTV-MODEL 2003
Authors: Yabe Akito , Fukada Saiji
Published: December 2023

Recent advances in computers and software have made it possible to solve in a practical time, even for large-scale 3D FEM models, while considering road bumps and the dynamic interaction between a vehicle and the road. In this study, a 3D FEM road traffic vibration analysis was tried
for flat roads, embankment road and cut road. And the results were compared with the predicted values from INCE/J RTV-MODEL 2003. These conclusions will give us useful suggest for the prediction of road traffic vibration.
A study of measurements and countermeasures for low-frequency noise caused by expressway bridges
Authors: Ikeya Kimikazu , Osafune Toshikazu , Iwabuki Hiroshi
Published: December 2023

Expressway bridges, though rarely, generate low-frequency noise caused by coupled bridge and road traffic vibration. This paper reports a case study on taking measurements and countermeasures of infrasound on an actual expressway bridge. First, the paper outlines a wind noise estimation
method that takes into account the effect of wind and reflects the frequency, mean velocity, and turbulence intensity on the measurements of infrasound. Next, a case study on an improved TMD (Tuned Mass Damper), one method to suppress low-frequency noise, is presented. An overview of the generator-type
TMD, in which the oil damper of the TMD is replaced by a linear generator, is given, and the results of a field test of its effectiveness are reported. The damping function of the generator-type TMD can be easily tuned by incorporating a variable resistance value into the generator. Through
these undertakings, energy from road traffic vibration can be effectively utilized, supporting reductions in environmental impact and making a significant contribution to the SDGs of expressway projects.
Study on acoustic properties of ultra-low-density polyurethane with Nano-Cellulose
Authors: Choi Kyoung-min , Park Jang-Seok , Oh Se-min , Jung Hunyoung , Ryu Jungho
Published: December 2023

Recently, polyurethane materials are commonly used as engine room sound-absorbing materials to reduce the weight of automobiles. Polyurethane materials have excellent sound absorption performance in the 800~2,000 Hz frequency range due to the structural characteristics of the material,
but the sound absorption performance of more than 2,000 Hz is insufficient. In the case of electric vehicles, it is important to improve the high frequency noise generated by the motor, and the need for modification of polyurethane materials has increased. High frequency performance can be
improved by improving the air permeability of polyurethane cells through the bonding structure of polyurethane materials, optimization of blowing and gelling reactivity, and the amount of foaming gas. Increased air permeability of polyurethane materials reduces density and strength. In this
study, Nano-cellulose is a highly functional new material with light and high mechanical properties through a chain bundle structure. The dispersibility is improved by optimizing the content and particle size of nano-cellulose. The goal is to develop ultra-low-density polyurethane with excellent
sound absorption performance in high frequency areas over 2,000 Hz and improved strength. The strength of hood insulation and dash outer products can be improved by applying the developed polyurethane material. In addition, the quality of lightweight engine room sound absorbing materials for
electric vehicles can be improved.
Issues facing Osaka International Airport and its dialogues with the surrounding communities
Authors: Inoue Makiko , Nishino Yoshio , Izumi Junshi , Matsubara Kenji
Published: December 2023

Osaka International Airport is an urban airport located close to the city center, and its operating hours are set at 14 hours, from 7:00 to 21:00. In the past, the airport had conflicts with local residents over aircraft noise. Even today, the airport needs to pay careful attention
to the communities to ensure smooth operation of the noise-generating airport. The flight schedule is set to allow enough time for takeoffs and landings in order not to exceed 21:00 based on the agreements with the surrounding communities; however, recently there have been many delayed flights,
takeoffs and landings outside of the operating hours, due to weather conditions or for other unavoidable reasons. We have gained a certain level of understanding of the surrounding communities for delayed flights by sharing appropriate information and holding regular dialogues with them. In
addition, Osaka International Airport has set specific flight paths called noise preferential routes to minimize the impact of aircraft noise around the airport and is using a system to monitor deviations from NPRs. This presentation is to introduce the current status of these activities and
methods for properly analyzing the information to provide to the community.
Effects of vehicle vibration on driver alertness: a pilot study
Authors: Xu Jinhui , Zhang Neng , Robinson Stephen R. , Davy John L. , Fard Mohammad
Published: December 2023

Road accidents resulting from the loss of driving alertness cause significant social and economic damage. In recent years, studies have revealed that whole-body vibration affects driver drowsiness directly. However, the impact of different frequency ranges of vibration on driver alertness
has not been extensively explored. This driving simulator study aimed to investigate the impact of low frequency (1-4 Hz) and high frequency (16-32 Hz) whole-body vibration on a driver's reaction time during a monotonous highway driving task. Nine participants completed the task for one hour,
with reaction tasks presented every 8-12 seconds. After 25 minutes of exposure to whole-body vibration, participants exhibited significantly longer reaction times for both low and high frequency ranges when compared to the control condition. The low frequency range had a stronger effect on
driver vigilance, with reaction times increasing by as much as 135 ms within 35 minutes. Subjective evaluations using the Karolinska Sleepiness Scale (KSS) were consistent with the reaction time results. Overall, this study confirms that both low and high frequency vibration can reduce driver
alertness, with the effect of low frequency vibration being more pronounced. Further research is suggested with larger sample sizes and wider frequency ranges.
Variations in sound environment in an urban apartment building: A case study during and after the COVID-19 lockdown
Authors: Yang Tingting , Kang Jian
Published: December 2023

Quiet communities, which are encouraged to maintain a harmonious and tranquil urban living environment, have attracted increasing attention in designing method in recent years. The relevant residential standards specify quiet thresholds with regard to noise pollution issues. However,
the variation in height across floors of high-rise buildings and variation with time in sound environments have not been examined in detail. The city of Shanghai experienced a city-wide lockdown to control the spread of COVID-19, showing evidence of quietness and a significant reduction in
anthropogenic noise. Here, we conducted noise monitoring in a 14-storey apartment building that was surrounded and shielded by other buildings in a typical urban community during and after the lockdown. The mean value of all 14 floors of equivalent continuous A-weighted sound pressure level
(LAeq,T) after lockdown was systematically greater than that during lockdown, with differences of 3.6 and 3.1 dB during the daytime and night-time periods, respectively. We suggest that in practice, it is useful to consider the specific floor or time of day.