bluuebunny/crossref_metadata_2025 huggingface dataset:
On the analysis of antiresonance frequencies for structural damage localization
Authors: Outzen Lukas , Ring Tobias P. , Langer Sabine C.
Published: December 2023

During the service life of long-lasting constructions, structural changes occur that can lead to damage or failure. For reasons of economic and ecological sustainability, it is of great importance to detect these changes as early as possible to ensure safe operation and to be able to
initiate maintenance measures if necessary. To detect and localize emerging damages, structural health monitoring systems can be employed. The realization of such systems requires methods that can derive information about the condition of the monitored object from measurement data. To develop
a better understanding of how damage affects structural integrity, simulation models of generic structures can be used. In most cases, structural damage can be generalized as some type of local stiffness reduction, causing changes in the dynamic properties of the structure. From a numerical
perspective, this means that the dynamic stiffness matrix of the system changes, which can lead to shifts in resonance and antiresonance frequencies. Since resonance frequencies are global characteristics of the structure, they may contain information about the occurrence of structural damage,
but not about its location. Therefore, this paper investigates whether and how the observation of the antiresonance frequencies can be used to both detect and localize damages.
Exploring the Potential of Virtual Environment for Electric Vehicle: Study Case and Sound Quality Performance
Authors: Tabsyira Aisha Asta , Sarwono Joko , Nitidara Ni Putu Amanda , Sudarsono Anugrah Sabdono
Published: December 2023

The consequent growth in the production and deployment of electric vehicles (EV), has urged a reassessment of the interior sound experience for these vehicles. To address the issue, this research employs a virtual environment (VE) with a circular array of eight loudspeakers and visual
projection to recreate the soundscape of the EV cabin. The validity of the simulator is evaluated by respondents both in the real cabin and VE. Two stimuli were reproduced in VE: 1. Stimuli with the same sound pressure level (SPL) as the cabin, 2. Stimuli's SPL is lowered by 9.5 dB. Data shows
that by reducing the SPL, VE implied a closer perception of the real cabin soundscape. Furthermore, T-test and Pairwise Comparisons results indicate that the VE is able to reconstruct several perception parameters of car cabin soundscape with no significant differences. Parameter classification
is also done with Principal Component Analysis (PCA) to reconfirm data behavior. These outcomes confirm that VE is possible to be a tool for modifying the sound design of armored electric SUVs with requiring deliberation on some factors.
Further investigation of horizontal sound localization in noise
Authors: Chen Daocheng , Yao Dingding , Gu Jianjun , Li Junfeng , Yan Yonghong
Published: December 2023

The accuracy of sound localization suffers significantly in a noisy environment. Noise can have an impact on the binaural localization cues such as interaural time difference (ITD) and interaural level difference (ILD). This impact is not only related to the signal-to-noise ratio (SNR),
but also to the noise level. Therefore, it's crucial to understand how to describe binaural localization cues in noise. This study investigates the effect of noise level (ranging from 80 dB to 95 dB) and SNR (ranging from -15 dB to -5 dB) on the localization of horizontal sound sources at
different azimuths. By analyzing the interaction between different binaural cues and localization accuracy in noise, the results demonstrate that there is a strong association between localization accuracy and interaural partial loudness difference. A follow-up experiment with modified ILD
confirmed that the interaural partial loudness difference might more accurately reflect the auditory localization properties of the horizontal sound source in noise.
An AI-powered Acoustic Detection System Based on YAMNet for UAVs in Search and Rescue Operations
Authors: Marinopoulou Theoktisti , Lalas Antonios , Votis Konstantinos , Tzovaras Dimitrios
Published: December 2023

An emerging application of unmanned aerial vehicles (UAVs) is related to search and rescue operations, where drones are used to detect emergency events, such as people screaming, explosions, or gunshots. As a result, this kind of service can provide critical support and enable a faster
response from the first responders to an area of interest. UAVs equipped with acoustic sensors constitute a beneficial surveillance system as opposed to visual sensors that face limitations due to lighting conditions or obstacles to the field of view. In this paper, an acoustic detection system
(ADS) capable of identifying such scenarios is presented using a ReSpeaker 4 Microphone Array and a Raspberry Pi 4B. For this purpose, a custom two-dimensional convolutional neural network (CNN) model based on YAMNet architecture has been implemented. The model was trained on public audio
datasets on targets related to search and rescue operations. Furthermore, an added class with mixup augmentation for overlapping events was created. The final system was adjusted to run in real-time conditions achieving an overall accuracy of 70.13% in indoor and 70.52% in outdoor environments,
respectively, revealing the potential of the solution.
Calibration of a cardioid microphone for improving accuracy of normal impedance measurement in a tube
Authors: Hoshi Kazuma , Hanyu Toshiki
Published: December 2023

This paper presents a method for obtaining the complex amplitudes of both the sound pressure and the particle velocity of a cardioid microphone. These values are used as calibration values in a new technique for measuring the impedance of materials using a combination of two cardioid
microphones placed in a tube. The previous technique, which utilized a single cardioid microphone placed in a tube, required two separate measurements to be taken - one with the microphone facing the specimen and one with the microphone facing away. This new method provides a more efficient
approach to impedance measurement.
Predicting the effect of microstructural variations in porous sound absorbers on their sound absorption performance using the perturbation method
Authors: Takahashi Hidetoshi , Yamamoto Takashi , Komatsu Yosuke , Yamakawa Keisuke , Katsura Daiji , Yukawa Hideyuki
Published: December 2023

Noise reduction is one of the most important issues in various industries. Quantifying the variation in acoustic properties is an essential task to improve the quality of products. Porous sound-absorbing materials are commonly applied to reduce noise. Variations in the microstructure
of porous materials have a significant impact on variations of sound absorption coefficient. Experimental methods have been used to predict manufacturing variability of sound-absorbing porous materials. However, they take a lot of time and cost. In this study, a perturbation method is applied
to predict variations of sound absorption coefficient of sound-absorbing porous materials combined with the homogenization method based on an asymptotic expansion. Properties of microstructure of a sound-absorbing porous material, such as fiber diameter and cell size, are assumed to follow
normal distribution and identify the expectation and variance from the observation of microscopic images obtained by scanning electron microscope. Calculated variability of sound absorption coefficient is compared with measured variability and they agree well in the frequency range of interest.
Clarification of Frequency Bands Affecting Attentional Mechanisms Using Event-Related Potentials
Authors: Kameyama Yuki , Ishimitsu Shunsuke , Kotaka Keisuke , Fujii Yasuto
Published: December 2023

In recent years, with the spread of electric vehicles, impressions of the sound of automobiles have changed. As automated driving becomes more widespread, we assume that a decrease in cognitive load will make it easier for drivers to pay attention to vehicle sounds, thereby increasing
their discomfort. This study focused on selective attention and aimed to quantify the attentional mechanisms of vehicle sounds from event-related potentials (ERPs). In addition, it is necessary to identify the characteristics of vehicle sounds that attract attention and awareness more easily,
reduce unwanted vehicle sounds, and make them more pleasant from a neurophysiological perspective. In this study, an experiment was conducted to measure brain responses while driving to identify the characteristics of sounds that are likely to attract attention, by observing changes in ERPs
for different frequency bands. These results may help investigators examine practical approaches to reduce vehicle sounds and improve comfort within car interiors.
Effect of occlusion effects by bone-conduction sound on speech perception assessed by monosyllable articulation test and confusion in phoneme perception
Authors: Miwa Asuka , Otsuka Sho , Nakagawa Seiji
Published: December 2023

Bone conduction (BC) has been applied to hearing aids for conductive hearing loss, earphones, and other audio devices including ones presenting sound to the face. One of the important characteristics of BC is the "occlusion effect (OE)", a phenomenon that low-frequency sound
are perceived as being enhanced when the ear canal is occluded. Our previous study examining OE in facial parts reported that the OE in some facial parts was larger than OE in parts conventionally used. In this study, we conducted monosyllable articulation tests using bone-conducted speech
with subjects' ear canal open and occluded, and investigated confusion in phoneme perception to evaluate the effect of OE on perception in the mastoid process, condylar process, nasal bone, and infraorbital region. The results showed that OE increased articulation. However, its effect varied
depending on stimulus location and acoustic characteristics of the phonemes, and even confusions among unvoiced consonants even increased by OE. These findings are useful for optimizing BC devices using OE.
Sound absorption analysis of carbon steel varied in density and microstructures
Authors: H Mardin , Kamil Kusno , Amri Ahmad , Rizal Muhammad
Published: December 2023

In many factories, noise is an important issue considering workers' health and safety; and metal blocks of the machinery is the main source of noise generated while running. Hence, the acoustical characteristics of the metal parts of machineries need to be considered in design. This
study aims to determine the effect of metal density to sound absorption (α) in order to reduce noise impact, including its correlation to the metal microstructures. The αvalues of specimen were measured on 5mm thick carbon steel -varies in carbon densities and well-known in metal
industries as ST 30, ST 42, and ST 60 standards. Through 5000x magnification of Scanning Electron Microscopic (SEM), the microstructures of carbon steel are identified. The results showed that in the high-frequency range (1200-1400 Hz) the highest α values occurred on ST 60 steel, while
in the low-frequency range (200-400 Hz), the α values were relatively similar for all specimen with a small discrepancy on ST 42. Homogenous metal grains with less gaps are clearly shown on ST 30 microstructures, while for ST 60 the grains seem varied in size and types, dominate with
carbon particles, making the steel more rigid and better for sound absorptive function.
Experimental investigation of unmanned air vehicle rotor aeroacoustics using benchmark geometries
Authors: Kekus-Kumor Pawel , Sieradzki Adam
Published: December 2023

A series of benchmark and off-the-shelf unmanned air vehicle rotors with diameters around 12 inches was tested in the newly-built anechoic chamber at the Łukasiewicz Research Network - Institute of Aviation, as well as in an open field. The aerodynamic performance of the rotors
was assessed using thrust and torque meters embedded in a custom testing rig, and their acoustic characteristics, including directivity, were determined using a column of free-field microphones. The characteristics of the anechoic chamber, including the spatial distribution of background noise
and the anechoic condition, were evaluated in detail, and the comparison with open-field measurements enabled confirmation of its suitability for testing of low Reynolds number rotors. The measurements of rotor performance were compared with published results, and the agreement between the
data sets validated the methodologies employed in this study. Furthermore, a new benchmark is defined based on an 8-inch commercial rotor, for which broadband noise is more significant than for larger diameters. A full set of aeroacoustic characteristics is presented, broadening the range
of available benchmark cases.
A basic study on sound absorption characteristics of disordered hyperuniform periodic structures
Authors: Sugahara Akiko , Dotera Tomonari
Published: December 2023

Disordered hyperuniform systems are exotic states of matter that cover the intermediate regime between random and periodic structures. Despite appearing disordered and isotropic, they possess a hidden long-range order. Our study aims to develop disordered hyperuniform microperiodic
structures that combine short-scale randomness and long-scale periodicity, making them versatile and useful for sound-absorbing materials, such as wall panels. To construct these structures, we generate a large number of three-dimensionally random waves within a specific frequency range, while
applying periodic boundary conditions. Using the finite element method, we analyze the sound absorption of the hyperuniform structures. Compared to simple Gaussian random fluctuations, we observe an increase in surface area, resulting in higher airflow resistivity, and a rise in the sound
absorption coefficient within the low to mid frequency range.
Frequency-discrimination and speech-perception characteristics of bone-conducted sound presented to the facial parts
Authors: Uemura Ko , Otsuka Sho , Nakagawa Seiji
Published: December 2023

Bone-conducted (BC) sound is typically presented to the mastoid process of the temporal bone or the condyle process of the mandible. However, a method of presenting BC sound to facial parts such as the nose and cheek have also been investigated recently. Since the face is one of the
most complex structures in the human body, slight differences in the presentation parts of the vibrator will also change the perception and propagation mechanism. However, the characteristics of BC sound presented to the face have not yet been studied in detail. We have previously discussed
the differences in perception (hearing thresholds) and propagation characteristics among facial parts. Here, to test the frequency-discrimination ability, we measured difference limens for frequency. We also conducted monosyllable articulation tests in Japanese to assess the speech-perception
characteristics when BC sounds are presented to various facial (nasal, infraorbital region, zygomatic, jaw angle, and chin) and conventional (mastoid and condyle process) parts. The results obtained showed that the frequency resolution and intelligibility of the facial parts were about the
same as those of the conventional parts. It is indicated that practical frequency information and speech perception are possible with BC devices attached to certain facial parts.
Impacts of the covid lockdown on the soundscape of an urban area: noise, psychoacoustic metrics and ecoacoustic indices
Authors: Alvares-Sanches Tatiana , Osborne Patrick E. , White Paul R.
Published: December 2023

Urban noise is both a serious environmental pollutant affecting ecological systems, and a major public health issue impacting millions of people worldwide. Noise levels are increasing and, without action, will lead to significant disruption of ecosystem services and a multitude of health
effects such as cardiovascular diseases, hypertension, hearing impairment, preterm births, decreased cognitive performance, sleep disturbance, annoyance, anxiety and depression. The covid pandemic presented a unique opportunity to study the soundscape of cities with reduced human activity,
especially the decreased use of motor vehicles, a primary source of urban noise. In this paper, we compare noise metrics, psychoacoustic indices and ecoacoustic indices derived from urban transect walks undertaken during (2020) and after (2022) the covid lockdowns in Southampton, UK. In this
way, we assess not only noise levels, but also changes to the quality of the urban soundscape. Our aim is to understand the "art of the possible" in improving the soundscapes of active cities, and to help better inform urban planners and health practitioners in tackling a serious
yet often hidden environmental crisis.
The effect of furniture on room acoustic parameters and its dependence on different suspended ceilings' sound absorptive properties
Authors: Nguyen Huong , Nilsson Erling
Published: December 2023

In ordinary public rooms such as classrooms and offices, the base line of acoustical treatment is an absorbent suspended ceiling. Due to the non-uniform distribution of the absorptive material, the scattering as well as the absorption properties of furniture will have a significant
influence on room acoustic parameters such as reverberation time, speech clarity and sound strength. In particular, the absorption of the sound scattered energy will depend on the absorbing efficiency of the suspended ceiling. This effect is not accounted for in classical diffuse field models
such as Sabine's formula. Measurements were conducted in the reverberant room with varying degrees of furnishing for several ceiling treatments ranging from highly reflective to highly absorptive. Using Sabine's formula and the Statistical Energy Analysis model, this paper discusses the scattering
effect of furniture on room acoustic parameters such as reverberation time, speech clarity and sound strength as well as how the equivalent scattering absorption area is related to the absorbing efficiency of the suspended ceiling. It is concluded that a novel method for the quantification
of furniture is needed to include both absorption and scattering effects of furniture on reverberation time and its dependence on the suspended ceilings' absorptive properties.
Vibration reduction indices for junctions between cross-laminated timber floors and lightweight timber framed walls
Authors: Mahn Jeffrey , Müller-Trapet Markus , Skoda Sabrina , Cunha Iara Batista da
Published: December 2023

Cross laminated timber elements are often used as the floors and the external walls in mass timber buildings in Canada, but the internal walls of these buildings are typically lightweight timber framed walls. The calculation of the flanking transmission loss and the apparent sound transmission
class for the mix of lightweight and mass timber constructions requires the laboratory measured vibration reduction indices or flanking level differences of the different flanking paths. Junctions constructed in the new four room flanking facility at the National Research Council Canada have
been used to evaluate both the vibration reduction indices and the flanking level differences of a cross laminated timber floor connected to lightweight timber walls.
Exposure response relationships of annoyance and vibration and noise from passenger and freight trains in Sweden - results from the EpiVib study
Authors: Waye Kerstin Persson , Kempen Elise van , Ogren Mikael , Vincens Natalia
Published: December 2023

Rail traffic is increasing in Europe, still little is known about the health effects of rail traffic vibration and noise for people living close to the railways. The aim of this study was to investigate the associations between vibration respective noise from rail traffic and persons
highly annoyed by vibration. The study population (N=7280) was randomly selected from residents (18-80 years) living within 1km of a trafficked railway in Sweden. Vibration and noise levels were modelled for each participant's home address. Result show exposure-response relationships between
levels of vibration and noise and annoyance for all types of trains, especially freight trains. The association between maximum vibration velocity at building foundation (Vmax) and high annoyance by vibration from freight trains, accounting for potential confounders was (OR=1.37 per 0.1mm/s
Vmax; 95% CI 1.32-1.42). Similarly, for railway noise (LAFmax) (OR=1.19 per 1 dB LAFmax; 95% CI 1.17-1.21). Analysis suggests an interaction between noise and vibration, where the effect of noise level on the probability of vibration annoyance by vibration differs with vibration exposure and
vice versa. These findings may have implications for environmental health and transportation planning. Keywords: rail traffic vibration, railway noise, annoyance by vibration, freight trains
Effects of noise on the hearing of intensive care unit nurses
Authors: Ziwei Song , Lee Pyoung Jik , Li Bin , Fei FuYuan , Hampton Thomas
Published: December 2023

This study aims to investigate the hearing problems experienced by nurses working in the intensive care units (ICUs) and gastroenterology departments of a hospital in China. A total of 93 participants who are currently employed in these settings were recruited for the study. The research
methodology involved several components. Firstly, the pure tone audiometry (PTA) hearing threshold measurements were conducted in a closed audiometry room. The air conduction hearing and bone conduction hearing thresholds were recorded using calibrated equipment. Secondly, the participants
underwent the Digits In Noise (DIN) test to assess their speech reception threshold in a noisy environment. They were instructed to wear headphones and adjust the volume to be a comfortable level while Chinese digit triplets were presented with a background masking noise. Thirdly, a questionnaire
with previously validated and subjective components was also administered after the PTA and DIN tests. The survey aimed to assess self-reported auditory dysesthesia, including symptoms such as tinnitus, aural fullness, and otalgia. It was observed that ICU nurses exhibited more hearing loss
at high frequencies above 4 kHz compared to non-ICU nurses. Additionally, nurses who worked more hours per week demonstrated worse hearing thresholds. Furthermore, ICU nurses reported more severe self-reported hearing problems compared with non-ICU nurses.
Toward Music-Related Sound Control and Hearing Conservation in the Leisure Soundscape
Authors: Chieng Julia , Tamrin Shamsul Bahri Hj. Mohd
Published: December 2023

Music-Induced Hearing Loss (MIHL) affects both musicians and participants of leisure soundscapes. Noise Risk Assessment and Hearing Conservation Program have been practised in the manufacturing and construction industries; however, these are rarely implemented in Cultural and Creative
Industries (CCI) that are also exposed to excessive sound levels. This paper includes an example from the Rainforest World Music Festival, Malaysia where data were collected from 2015 to 2017, through sound pressure level (SPL) measurements, semi-structured interviews (60 participants) and
a survey (1,194 respondents). Despite SPL measurements showing levels exceeding the recommended noise limit, the study reported a majority of 68% perceived the loudness of the music festival as "perfect" whilst 21% as "loud but acceptable". In leisure soundscapes, sounds
are featured aural products in demand and encapsulated in cultural meanings with voluntary listening behaviours. Thus, some of the existing guidelines in occupational noise exposure may not be transferable. As recommendations, it is essential for an extensive study on the development of a
focused framework to incorporate music-related sound control and hearing conservation in reducing the risk of MIHL while preserving the social-cultural value, creativity in arts and rewards in the hearing experience of a leisure soundscape.
Additive manufacturing of membrane-type acoustic metamaterials
Authors: Johnston William , Ciletti Anthony , Sharma Bhisham
Published: December 2023

Traditional membrane-type acoustic metamaterials have been proven to act as effective lightweight sound insulation materials. However, their geometries cannot be easily incorporated into other acoustic designs in a single workflow. Here, we leverage the enhanced customizability that
additive manufacturing provides by introducing 3D printed membrane-type metamaterials that can one day be seamlessly incorporated into a variety of acoustic designs without the need for post-processing. In this study, we present the fabrication workflow to 3D print membranes of varying thicknesses
and offer an analysis on print quality. Using a four-microphone normal-incidence impedance tube, we provide preliminary results on the sound transmission loss behavior of these membrane-type metamaterials. Our results show the membranes are fabricated without any significant holes or gaps,
and their thicknesses can be reliably controlled.
Going to Scale: Broadening Marine Mammal Noise Exposure Criteria for Behavioral Responses
Authors: Southall Brandon L.
Published: December 2023

There has been considerable interest in and advances made in both measuring the effects of noise on the behavior of marine mammals and synthesizing results into response thresholds and/or probabilistic functions used in noise criteria. Many of these approaches apply severity 'scales'
with presumed gradation of response severity to evaluate specifically identifiable responses in individual or groups of animals exposed in discrete, acute exposure conditions. There has also been considerable and important research looking at disturbance on seasonal or annual timescales for
local or regional populations exposed to broader scale or sustained disturbance. However, as yet there has been limited systematic effort to establish behavioral response criteria for these scales. Such criteria, which are certainly needed in many management jurisdictions around the world,
will require fundamentally different approaches, metrics, and outputs than acute noise criteria. This paper will consider several possible new approaches and recommend specific steps to begin developing noise criteria for broader, and in some ways more realistic, spatial and temporal scales.
Keywords: marine mammals, noise, behavior, response, severity, criteria
Effects of orienting attention to a specific frequency on medial olivocochlear reflex - A study of dependence on target frequencies -
Authors: Kikuchi Shoma , Ishizaka Yuki , Otsuka Sho , Nakagawa Seiji
Published: December 2023

The medial olivocochlear bundle responds to acoustic stimuli and suppresses outer hair cell gain. This reflex response is called the medial olivocochlear reflex (MOCR) and improves signal detection in background noise, referred to anti-masking effect. Our previous study reported that
orienting attention to moderate frequencies selectively increases MOCR near the attended frequency, and that the effects of attention to low and high frequencies are unlikely to appear in MOCR. The previous investigation was limited to the condition where participants kept orienting attention
to the same frequency across trials. Here we examined the condition where participants switched attention to different frequencies trial by trial. During the measurements of MOCR, participants detected probe tones in background noise. The target frequency, 750, 1000, 1250, 1500, 2000 and 3000
Hz, was notified by a preceding cue frequency and varied across trials. When the target frequency was 1250 Hz, the MOCR strength tended to be attenuated at lower frequencies. In contrast, for any other target frequencies, MOCR didn't differ significantly from a non-attentional condition. The
frequency range where attentional effect was observed was similar to our previous report. The similarity implicates that MOCR can covary with dynamically changing frequency-specific attention, which would help exerting antimasking effect flexibly.
Prediction of surface admittance impulse responses from frequency-dependent sound absorption coefficients
Authors: Huszty Csaba , Firtha Gergely
Published: December 2023

In numerical room acoustic modeling certain material properties are required as inputs for setting the boundary conditions for the calculations. In finite element or finite difference models, locally reactive boundaries are often represented as FIR or IIR filters. However, most building
material manufacturers provide sound absorption coefficient or equivalent absorption area data only, in accordance with the relevant standards, so a method to convert sound absorption to admittance or impedance impulse responses is required. Since there is a loss of information when admittance
is converted to sound absorption coefficients, the conversion in the opposite direction has multiple solutions. We derive an iterative method of determining either the impedance or admittance impulse response from arbitrary, frequency-dependent diffuse sound absorption coefficients and validate
it with the transfer matrix method. We present the implementation of the method in the soundy.ai application.
Aviation Noise in the United States: The Current State of Federal Aviation Administration Research on Community Response
Authors: Scholten Adam , Scata Jr. Donald , Grandi Fabio , Czech Joseph J.
Published: December 2023

Despite today's civilian aircraft fleet being quieter than at any time in the history of jet-powered flight, communities in the United States continue to file complaints about aircraft noise. Additionally, the Federal Aviation Administration's (FAA) Neighborhood Environmental Survey
(NES) has shown that community response to aviation noise in the United States has changed and the dose-response relationship between noise and annoyance such as the one represented by the Shultz Curve is no longer representative of communities' lived experiences. This paper will examine the
current aviation noise environment in the United States, and how the nature of aviation noise and the characteristics of communities that raise significant noise concerns in the United States have changed since the start of widespread use of commercial jet-powered aircraft in the 1960s. This
paper will also explore the changing nature of community response to aviation noise based on the FAA's latest research findings on aviation noise and annoyance as detailed in follow-on analyses to the NES.
Representativity of ISO test track surface based on controlled pass-by measurements
Authors: Berge Truls , Mioduszewski Piotr
Published: December 2023

Within the Polish-Norwegian research project ELANORE, a limited Round Robin Test has been performed on four ISO tracks in Northern Europe. The basic objective of the project is to improve the EU directive on labelling of tyres for noise and rolling resistance. This directive is based
on the measurement procedures proscribed in the UNECE Reg.117. Measurements on 3 ISO tracks were performed in 2021 and presented at InterNoise 2022. This paper adds results from tests conducted on a fourth ISO track as well as on trafficked roads with different conventional pavements: 2 in
Norway (MA11 and SMA16) and 3 in Poland (SMA8, SMA11 and EACC). On all ISO test tracks and road test sites the same car, test tyres and test equipment as well as the same personnel were used to minimize the measurement uncertainties. Measurements were done using the controlled pass-by (CPB)
method for vehicle test speeds between 40 and 90 km/h, with 2 test conditions: according to Reg.117 and with so-called "light test conditions". The main conclusion is that the noise ranking of the tyres on both, the ISO tracks and conventional pavements do not correspond to the ranking
based on the label values given by tyre manufacturers.
Sound improvement emitted from copy machines
Authors: Hashimoto Takeo , Hatano Shigeko
Published: December 2023

There are many copy machines in our office rooms for hard copies of our written materials. To get the outputs, we frequently meet chance to hear unwanted sound from the copy machine. What we want is the hard copy of some articles and not for the unwanted sound emitted from the copy
machine. For the solution of reduction of our unpleasant sensation, the trial treatments for improvement of our sensation are conducted. This paper shows the relation between the treatment of sound and subjective results for explaining the cause and results. The keys to reduce unpleasantness
are to reduce the duration of the decaying part of the sound in question and to reduce the peak level of the sound. It is also effective if we could be able to extend the time interval of the adjacent peaks.
On the relationship between the vibration characteristics of the automobile wheel and generated road noise in the vehicle cabin
Authors: Kobayashi Sho , Kiyotaki Ryo , Li Zhe , Terashima Osamu
Published: December 2023

The relationship between vibration characteristics of an automobile wheel and the generated road noise in the vehicle cabin was investigated experimentally and numerically because it is one of the vibration transmission paths caused by the input force from roads. Experiments were conducted
using 15-inch wheels in two different vibration characteristics, and the results were discussed based on the measurements of the noise in the cabin and vibrational acceleration of the sub-frame of the vehicle when driving on smooth and rough roads at a speed of 30 km/h. Further, transient
analysis using FEM was also performed using a tire-wheel assembly model. The results showed that large differences were observed in the generated noise of 49, 90, and 167 Hz in the case of the smooth road, and these differences were due to the difference in the magnitude of vibrational accelerations
of the wheel at these frequencies.
Vehicle seat surface real-time control system with linear actuator to reduce vertical impact
Authors: Li Zhe , Kiyotaki Ryo , Kobayashi Sho , Terashima Osamu
Published: December 2023

For regular vehicles, the vibration generated when a vehicle passes through a groove or step is dampened but still remains and causes whole-body vibration (WBV) to occupants through vehicle seat. Several epidemiological studies have clearly demonstrated that prolonged exposure to vibration
from vehicles is detrimental to human health and may cause motion sickness. To reduce this whole-body vibration. We designed a simple and effective feed-forward control system with compact actuator compatible to the limited under-seat dimension and power outlet of compact general passenger
cars and successfully authenticated the possibility of vertical vibration reduction by controlling the vehicle seat surface vertical displacement. In this research, we designed a real-time feed-forward control system with transfer function model estimation. This real-time control system contains
a commercial DSP device providing coherence input and output with a controllable delay. With the application of transfer function model and state space model, this system successfully estimated the upcoming vibration acceleration according to the input of the vibrational acceleration time-domain
data acquired from lower arm when the test vehicle passing a step. Furthermore, it is possible to process the input data and control the linear actuator precisely to reduce the vertical impact observed as setting force reduction.
Reduction of Aerodynamic Noise radiated from Rectangular Cylinders in Cross Flow
Authors: Ishida Natsuki , Higuchi Masaya , Hamakawa Hiromitsu , Kurihara Eru
Published: December 2023

In the present paper the attention is focused on reduction of noise generated from rectangular cylinders in cross flow. The width-to-height ratios of was 3.0. The tube pitch ratio in the transverse direction was 8.0. We measured the aerodynamic sound radiated from the rectangular cylinders
in the range of Reynolds numbers from about 10^3 to 10^4. The several high peaks were formed at the spectrum of SPL. The sound power of vortex shedding noise was proportional to the freestream velocity to the power of six. On the other hand, the strange noise occurred at five times the vortex
shedding frequency. We have discussed how to counteract the noise generated by rectangular cylinders.
A segment-based A-weighted sound propagation model for road traffic noise assessment: A general concept
Authors: OSHIMA Takuya , KOSHIBA Yusaku
Published: December 2023

The propagation model of the road traffic noise established by the Acoustical Society of Japan, the ASJ-RTN Model 2018, directly obtains the A-weighted sound pressure level by assuming specific power spectra of vehicle sources in a single calculation. This is more effective in reducing
computational burden than European models, which typically require calculations in eight bands from 63 Hz to 8 kHz. However, the ASJ model has not been generalized enough to deal with an arbitrary terrain profile, contrary to the European models where the handling of a segmented terrain profile
is integrated. This will become a major obstacle in realizing noise mapping in Japan. In this paper, a concept of an A-weighted sound propagation model for road traffic noise with integrated handling of a segmented terrain profile is presented. The model combines the segmented modeling of
multiple diffractions over a complex profile and the Fresnel weighting of ground characteristics both employed by Harmonoise, the mean plane for ground modeling used in CNOSSOS-EU, and the calculation of the excess attenuation terms following the ASJ model. Preliminary calculation results
show that the model agrees reasonably well with finite-difference time-domain simulation results on flat and uniform ground, but still needs investigation for non-flat and nonuniform ground.
The importance of experimental airframe noise research
Authors: Pott-Pollenske Michael
Published: December 2023

Numerical methods progress rapidly in terms of capabilities and efficiency. Accordingly, one could conclude that experimental activities will sooner or later disappear. In this context the paper will exemplify the use of numerical methods for the proper design and conduct of wind tunnel
experiments. Examples will cover the research topics on high lift system's aero-acoustic and landing gear noise. Finally, the paper will describe the development of selected noise reduction concepts from their first experimental assessment in wind tunnels up to being flight tested.
A pilot study on the sound insulation performance of plenum doors
Authors: Sakagami Kimihiro , Inoue Haruhi , Okuzono Takeshi
Published: December 2023

Demands for natural ventilation is inaugurated recently, particularly after the COVID-19 outbreak. Various ventilating windows have been proposed, one of which a plenum window has been studied for these years. Since the COVID outbreak shops and restaurants often leave doors opened for
ventilation reasons during their business hours. However, by this, the indoor sound environment is suffered by incoming noises from streets. Therefore, it is desirable that a sound insulation structure enabling natural ventilation is developed. In this study, we propose a door with plenum
structure which is an application of the same principle of plenum windows to a door. Doors and windows are of different sizes, and under different conditions. Therefore, in this paper, as a pilot study, we employed finite element method to analyse the sound insulation characteristics of a
plenum door. Results show that a plenum door, although its sound insulation is not very high, shows sound insulation performance to a certain extent. Also, a parametric study is given to show the effect of parameters including that of sound absorption linings.
Analysis of Helmholtz resonator wall elasticity effects on the performance of periodic acoustic metamaterial
Authors: Laly Zacharie , Mechefske Christopher , Ghinet Sebastian , Ashrafi Behnam , Kone Charly T.
Published: December 2023

In this paper, a metamaterial made of a porous layer with embedded periodic Helmholtz resonators is studied and the effects of the resonator wall elasticity on the acoustic attenuation performance of the metamaterial are investigated numerically. The analytical transmission loss results
using the parallel transfer matrix method show good agreement with finite element results for the rigid wall case. Elastic materials with different thicknesses are considered for the wall of the neck and the top, lateral and bottom walls of the resonator cavity. It is shown that the transmission
loss of the metamaterial degrades when the bottom wall of the resonator cavity is elastic. The elasticity of the bottom wall has a significant impact on the performance of the metamaterial. This analysis will help for better design of acoustic metamaterials with periodic Helmholtz resonators.
Vibration-based performance analysis between lithium-ion and lithium-polymer batteries
Authors: Awan Umar Shafique , Ghabraie Kazem , Zolfagharian Ali , Rolfe Bernard
Published: December 2023

This study aims to determine whether lithium-ion or lithium-polymer batteries are better suited for usage in applications with high levels of vibration, such as electric vehicles, by examining their responses to vibration. Both types of batteries were subjected to vibration testing
according to the International Electrotechnical Commission (IEC) 62660-2 standard for a full 24 hours at a frequency range of 10-2000 Hz. Both types of cells were put through a 10-cycle cycling test before and after vibrations, during which they were charged and discharged repeatedly. According
to the findings, both types of cells display a rise in Nyquist impedance and a drop in cell capacity. However, these effects were more pronounced in lithium-ion batteries than in lithium-polymer batteries. These results show that lithium-polymer batteries may be more robust to vibrations than
lithium-ion batteries, which might have substantial consequences for selecting viable battery types for use in electric vehicles. Overall, the results of this research offer significant new insights into the performance characteristics of these two different types of batteries, and they contribute
to the body of information already present in the area of electric vehicle battery technology.
Pilot study on evaluation indices for aircraft noise considering sound quality
Authors: Shinohara Naoaki , Shimoyama Koji , Nakazawa Toshiyasu , Morinaga Makoto , Kobayashi Tomohiro , Hanaka Kazuyuki
Published: December 2023

In Japan, Lden is currently used as an evaluation index for aircraft noise. It is based on the A-weighted sound pressure. It evaluates differences in noise loudness, but it does not necessarily take into account differences due to changes in sound quality. Over the past several decades,
single event of aircraft noise has been significantly reduced. As a result, we have experienced a change from the "noisy" sound quality of the old generation jets to the "soft" sound quality of the recent aircrafts. Has the sound quality really improved, and has its improvement
been evaluated? On the other hand, since the 2000's, we have sometimes experienced hearing the extraordinary tonal sounds from landing aircraft. It has the characteristics of pure tonal tone with 250-500 Hz and has a short duration and a prominent level fluctuation. Doessuch a sudden tonality
change, which is also negatively perceived, not affect the evaluation? This paper describes the results of trial calculation in order to examine the possibility of evaluating aircraft noise considering its sound quality, based on several indices such as EPNL, loudness, sharpness, and Tonal
Audibility (TA), in addition to the A-weighted noise (LAmax, LEA), and its comparative verification including differences in aircraft generations.
Experimental study on the sound of water flowing through a storm drain
Authors: Sawaki Shimpei , Tsuchiya Yuzo , Yamauchi Takashi , Takenaka Yuki
Published: December 2023

In buildings where storm drains are installed indoors, the sound of running water radiated from the surface of storm drains during rainfall may raise the noise level in rooms near the drain. To take appropriate measures against such sound according to the required quietness for the
room, quantitative data on the sound of running water from storm drains is necessary, but few studies have dealt with this kind of sound. Therefore, the authors conducted experiments in an existing building, a drainage test tower, and a reverberation room to understand the characteristics
of the sound produced by storm drains. Based on the results obtained through these experiments, this paper presents the effects of flow rate, pipe diameter, pipe material, and horizontal piping on the sound of running water from storm drains. The paper also discusses the differences between
the sound generated by storm drains and the sound generated by sanitary sewers.
Low frequency noise control using coupled loudspeaker and negative impedance circuit
Authors: Zhang Shiqi , Zhao Xiaochen
Published: December 2023

It remains a technical challenge for low-frequency duct noise control devices to combine compact and broadband features at same time. A semi-active noise control approach is introduced to solve this problem. The device consists of a main pipe and two loudspeakers connected by a circuit
containing a negative impedance network. Due to the effect of the negative impedance circuit, the virtual bypass is composed of the coupled loudspeaker and the circuit has sound transmission characteristics close to a physical duct in a certain frequency range. The effect of the negative impedance
network and circuit on the performance of the silencer is studied by using the transfer matrix method. Through the design of the circuit, the sound transmission process of the virtual bypass can be realized. If the proper circuit network and parameters are selected, the virtual bypass HQ tube
can achieve compact broadband noise control at low frequencies. A semi-active noise control device has 10dB noise reduction in the range of 100-300Hz.
The need for auditory-friendly classroom environment for children with autism spectrum disorder
Authors: Takahashi Hidetoshi , Ueno Kanako
Published: December 2023

Sensory abnormalities have often been reported as symptoms of ASD, and auditory over-responsiveness (AOR) isthe most common sensory-perceptual abnormality in individuals with Autism Spectrum Disorder (ASD). This abnormality has been reported to interrupt behavioral adaptation, and sometimes
even requires therapeutic intervention. Recently, we reported that a greater magnitude of acoustic startle reflex in response to weak stimuli of 65-85 dB was found in children with ASD compared to those with typical development. This index was related to various clinical features, including
sensory problems, autistic traits, emotional/behavioral difficulties, and adaptive/maladaptive behaviors in ASD children. This intensity level of acoustic stimuli is frequently experienced in everyday situations including the classroom environment. We addressed sound environmental issues in
several different types of school, including special-needs schools and nursery schools in several areas of Japan. Creating an auditory-friendly classroom environment that provides a comfortable and inclusive learning space is an especially important issue to address for the healthy development
of ASD children with AOR.