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Mass timber family of products (including cross-laminated timber -- CLT) offer an alternative to fossil fuel-intensive materials for many applications and an opportunity to reduce the carbon footprint of the built environment. However, the use of mass timber in multi-family and commercial buildings presents unique acoustic challenges. Additionally, one of the most desired aspects of mass timber construction is the ability to leave a building's structure exposed as finish, which creates the need for asymmetric assemblies. This means that when speaking about floor/ceiling applications, preferentially any acoustical component should be installed on top of the assembly. To measure airborne sound reduction and impact noise isolation of lightweight floating floor systems and confirm CLT assemblies can provide satisfactory sound insulation, CDM Stravitec launched a testing campaign (done on Belgian Building Research Institute, institution recognized by application of the decree-law of the 30th of January 1947), where measurements were made considering several types of decouplers, such as: discrete bearings with multiple thickness and/or different void depth (filled in totally or partially with insulation material) and mats and strips placed between the CLT slab and different timber, cement and gypsum-based boards with and without use of the well-known constrained layer damping technique. This paper will present the findings of the test campaign. [ABSTRACT FROM AUTHOR]

The computing superstructure necessary for self-driving cars to function presents a unique acoustics problem - the fans produce significant amounts of noise within the cabin that is uncomfortable for passengers. To ensure consumer comfort and promote more widespread adoption of the technology, soundproofing is required. Any soundproofing solution must not compromise the ability of the selfdriving computer to function, meaning that air flow must be preserved. To this end, the UTA Senior Design team creates testing procedures to identify the sound profile of May Mobility's Toyota Sienna. After identifying the frequency range and intensity of the fan noise within the cabin, the team can narrow down potential soundproofing solutions. Given the noise frequency range and air flow requirements, three materials that show promise are identified. The team's testing of varying configurations of cork, open-cell charcoal foam, and closed-cell neoprene foam to determine the most effective solution resulted in the identification of charcoal foam as the optimal material. Soundproofing structures were strategically placed around the computing superstructure and achieved a noticeable reduction of noise within the cabin. [ABSTRACT FROM AUTHOR]

Floating floor systems are part of state-of-the-art modern building technology. They are an efficient option to improve the acoustical performance of buildings and can be part of box-in-box systems installed in high-performance spaces. There are many types of high-performance floating floor types, one of which is a jack-up system that guarantees that the floor is decoupled from the structural floor. With these systems, once the concrete has cured, the isolated slab is raised off the structure to the required void depth using pre-cast boxes. These boxes allow for easy adjustment of the final floor height and, if the use of the room or load conditions change in the future, can also allow the replacement of the isolators inside them. Replaceable and inspectable acoustical floor systems are perceived as systems with lower sound insulation (airborne noise) than traditional floating floor or non-replaceable jack-up systems. To measure airborne sound reduction and impact noise isolation of replaceable jack-up systems and confirm factors that can influence its performance, CDM Stravitec invested in a testing campaign, where measurements were made considering many variables, such as: concrete floating slab thickness; bearings type, air void depth, steel lid installed on top of each box and insulation material installed in the air void. This paper will present the findings of the test campaign. [ABSTRACT FROM AUTHOR]

The double membrane-type acoustic metamaterial with negative pressure cavity (double MAM-NPC) is designed to achieve low frequency sound insulation. The double MAM and the sidewalls enclose the cavity. The theory of transfer matrix is used to discuss the transmission loss (TL) of double MAM-NPC. Under the action of negative pressure in the back cavity, the MAM undergoes geometric nonlinear deformation. Furthermore, the structure of inserting microperforated panel into the cavity of MAM-NPC (double MAM-NPC-MPP) is designed to improve the low frequency sound insulation. [ABSTRACT FROM AUTHOR]

Architectural structures are designed and built to provide a comfortable living space to their users due to their function. One of the most important comfort expectations in buildings is acoustic comfort. Since the impact sound insulation between floors, which is one of the sub-headings of acoustic comfort, is evaluated together with the floor covering, resolving the discomfort caused by incomplete or incorrect evaluations during the design phase can be both more difficult and more costly during operation. In practice, it has been observed that there are differences between the laboratory measurements made according to the EN ISO 10140-3 standard and the calculations made according to the EN ISO 12354-2 standard for impact sound insulation. This difference can lead to an uncomfortable living space as the targeted acoustic performance cannot be achieved. This situation creates the need for a calculation model that gives more realistic results during the design phase. In this study, the variables that cause the difference between laboratory measurements and calculation results in impact sound insulation will be examined and improvement suggestions will be developed for the calculation of impact sound insulation according to the EN ISO 12354-2 standard. [ABSTRACT FROM AUTHOR]

The incorporation of acoustic metamaterials in the design of aircraft fuselage panels in order to reduce the cabin low frequency noise is nowadays a major research subject aiming at offering passengers a comfortable cabin environment. In this study, acoustic metamaterial made of Helmholtz resonators periodically embedded into a porous material is investigated using transfer matrix approaches combined with finite element calculations. These transfer matrix methods are based on the two-load methods where the two loads in the numerical simulations are two different termination conditions (plane wave radiation and rigid wall) in order to retrieve the equivalent transfer matrix of the porous layer with embedded periodic Helmholtz resonators. The equivalent matrix is then coupled analytically in series with others analytical matrices to model complex multilayer metamaterials. The results of the transmission loss obtained exclusively using finite element method for single and double wall configurations are compared with the results of the proposed transfer matrix methods and good agreements are obtained. It is observed that the frequency band of the transmission loss of the double wall configuration is larger than the single wall configuration with higher transmission loss peak value. The investigated metamaterial can potentially be used in the design of aircraft cabin panels for low frequency noise reduction. [ABSTRACT FROM AUTHOR]

Buildings must ensure sound insulation appropriate to their use. This sound insulation is regulated by building regulations. In many Europe countries this is by use of the weighted apparent sound reduction index R'w or the weighted standardized level difference DnT,w. This paper shows that a direct assignment of the quantities R'w and DnT,w is only possible for certain geometric ratios of room volume to separating area (V/S). If a permissible deviation between R'w and DnT,w is accepted, a classification of sound insulation values (R'w) with fixed class limits can be made. This makes it possible to classify the sound insulation with reference to the descriptive parameter DnT,w using the weighted apparent sound reduction index R'w. [ABSTRACT FROM AUTHOR]

Timber framed houses have little or no sound insulation at low frequencies. A significant set of noise sources emit loud low frequency noise and for some of these, the noise is single frequency or tonal. Improvement of the low frequency insulation has been shown using two methods: increasing the stiffness and applying vibration neutralizers to the structure of the house. A study was carried out on a wall element to assess the viability of the method in a simplified test facility. Impedance measurements were carried out on a test section consisting of 3 studs and panel construction. An initial field implementation has been carried out on a re-purposed dwelling at the end of the runway at Bergen's airport. Reductions of the order of 5-10dB in the C-weighted indoor noise level have been achieved. The additional attenuation achieved using vibration neutralizers only has effect when the outside noise level exceeds 87dBC. [ABSTRACT FROM AUTHOR]

A new method of sound insulation measurement of building components based on near-field acoustic holography is proposed in the paper. First, multi-channel measurements are performed at the nearfield position of the member using a microphone array, and the measured holographic surface complex sound pressure is reconstructed by a spatial sound field transformation algorithm to find the normal sound intensity distribution on the surface of the member. Then, a window function is applied in the wave number domain to separate the propagating and swift waves to obtain the normal sound intensity distribution of the propagating waves on the surface of the component, and then calculate the magnitude of the sound power radiated from the component to the receiving room; finally, the radiated sound power of the component is converted to the incident sound power of the source room to obtain the frequency characteristics of the airborne sound insulation of the component, and the sound insulation defects of the component are detected based on the acoustic image. The basic principle of the near-field acoustic holographic sound insulation measurement method is explained in the paper, and the accuracy and validity of the method are verified through experiments. [ABSTRACT FROM AUTHOR]

Predicting the sound insulation between two rooms is a complex problem since not only the direct path through the separating element but also the flanking transmission paths can largely influence the sound insulation of the system. An important parameter for calculating flanking transmission is the vibration reduction index, which relates to the transmission coefficient between the connected plates. The international building acoustics standard ISO 12354-1/2 provides prediction formulas for the vibration reduction index of single wall junctions, but not for double wall junctions. A new hybrid diffuse-deterministic approach is proposed to calculate flanking transmission across double wall junctions. The walls and floors are modelled as diffuse subsystems while the connection between the double wall is modelled deterministically. In the derivation of the transmission coefficient between two diffuse subsystems, the diffuse field reciprocity relationship is employed, such that the finite size and structural details of the junction are taken into account. The diffuse field reciprocity relationship relates the vibration transmission to the direct field dynamic stiffness of the diffuse subsystems (walls and floors), i.e., the dynamic stiffness of the equivalent infinite subsystem as observed at the junction. The new approach is applied to different types of double wall junctions to determine simplified regression formulas for practical sound insulation design. [ABSTRACT FROM AUTHOR]

SOPRANOISE targets a three-step approach for assessing the in-situ intrinsic acoustic performance of road/railway noise barriers in regard to airborne sound insulation and sound reflection under direct sound field conditions. This approach goes from the in-situ inspections method (targeting at the acoustic effect in the far-field) to the standardized measuring methods EN 1793-5 and 6, with "quick and safe" measuring methods in between. Papers about SOPRANOISE have already been presented in 2020 and 2021 as progress reports. The research ended in March 2022 and the final outcomes are now presented. The main part of the pending work has been done within Work Package 4 (WP4). Herein, a new "quick and safe" method was designed and validated both in the lab and in situ. The new measuring equipment is portable, lightweight and uses a linear antenna; the measurement itself is fully automated and the results show a very good correlation with full EN 1793-5/-6 results. WP4 results are particularly successful and, together with the in-situ inspection, those methods are ready to be submitted to the relevant CEN/TC226/WG6 working group to draft a new framework on noise barriers assessment. All main reports are public available on the SOPRANOISE and CEDR webpages. [ABSTRACT FROM AUTHOR]

Timber buildings are now present worldwide, and their market is growing rapidly, pushed by sustainability and environmental arguments. Several technological options for engineered wood systems are available and well developed, the most common being wooden joist, CLT and timber hollow box. In this paper, we present a comparative study of impact sound insulation of the three options. The analysis is based on data collected from laboratory measurements. The results include the comparison of the bare floor construction and examples of assemblies with additional floating floor, suspended ceiling or a combination of the two. We identify the characteristic trends and highlight the effect of selected parameters as for instance mass per unit area, assembly thickness and properties of the resilient layers. The comparison attempts to show the constructive consequences of the different options on the sound insulation properties. It could help selecting the most suitable floor system in future projects and contribute making timber construction more efficient and affordable. [ABSTRACT FROM AUTHOR]

In September 2021, the document that develops an acoustic classification scheme was approved in Spain. It is the UNE 74201 standard that is described in this paper. The Spanish ACS is applicable to new and existing buildings for private or public residential use, for health/hospital and educational use. The development of this document has been a challenge which, requested by the construction sector, has been completed after 5 years of collaborative work, within the Technical Committee CTN74/SC2 - Building Acoustics of the Spanish Standardisation Body, UNE. It's been achieved an ACS compatible with the "DB HR" Spanish building acoustics regulations and, in turn, in agreement as much as possible with ISO/TS 19488:2021. The standard defines different levels of noise protection by using a system of six classes for the requirements, A to F, where Class D defines the minimum requirements for acoustic quality that are mandatory to fulfil in the building code. Criteria for airborne, impact and façade sound insulation, for service equipment noise and for reverberation time are included. This paper shows in detail the verification, sampling and class assignment procedures developed in the standard. A comparison of the most general aspects with other European schemes is also shown. [ABSTRACT FROM AUTHOR]

Wooden structures are becoming quite common in the French architectural landscape, and ACOUSTB has made it a specialty regarding acoustics. Its experience ranges from office buildings to residential buildings, and from small to high-rise constructions. Airborne and impact noise insulation are of first importance. Structural aspects, construction methods and architecture are also discussed. Constructive solutions concern both CLT and traditional wood joists flooring systems, alternatives to floating screeds in office buildings and visible wooden structures in dwellings. Buildings are described, then selected constructive solutions are presented and debated with respect to targeted acoustic performance. Finally, in-situ measurement results are compared with the theory that underlays them, as well with the targeted performance. [ABSTRACT FROM AUTHOR]

In recent years, the installation of new wind turbines has been promoted in Japan. Since wind turbines are often installed in quiet countryside, it is necessary to properly evaluate the noise impact of wind turbine installation. Since wind turbines are thought to have visual as well as auditory effects, we conducted a subjective evaluation experiment on the loudness and annoyance of wind turbine noise (WTN) and road traffic noise (RTN) by magnitude estimation method, using a three-dimensional audio-visual reproduction system consisting of 6 channels of loudspeakers installed around the sound receiving point and a dome screen. As a result, the loudness and annoyance of WTN tended to be evaluated higher than that of RTN. These results were considered to be influenced by the amplitude modulation called "swish sound" and the low-frequency dominant frequency characteristics, which are characteristics of WTN. In addition, when comparing the differences in loudness and annoyance with and without visual information, the two attributes tended to be lower when visual information was present. [ABSTRACT FROM AUTHOR]

It is common assumption that resilient joints around a heavyweight construction improve sound insulation between adjacent rooms. Effect of resilient joints on sound insulation has not been studied sufficiently. This study investigated how the joint resiliency around a heavyweight wall affected sound reduction index (SRI) measured directly through the construction. A calcium silicate block wall was built three times in a laboratory using three different joint types A-C between the wall and the building frame: A) all four edge joints rigid, B) three resilient and one rigid joint, C) all four joints resilient. SRI was determined for A-C. Total loss factor (TLF) was determined for A-C by measuring structural reverberation time using hammer impact stimulus. SRI reduced, remarkably, with increasing level of joint resiliency. Rw was 50 dB for joint type A while it was 45 dB for joint type B and 43 dB for joint type C. Correspondingly, TLF reduced with increasing level of resiliency. The effect of joint type was evident above the critical coincidence frequency 200 Hz of the wall. Resilient joints prevented the sound transmission to the building frame, which increased sound radiation to the receiving room. Therefore, heavyweight wall should be mounted to surrounding heavy constructions using rigid joints if high sound insulation is desired above the coincidence frequency. [ABSTRACT FROM AUTHOR]

In this work, we investigate the potential of considering a non-uniform material distribution in the design of panel partitions, in order to achieve a superior vibroacoustic performance close to a given target frequency. In order to achieve this goal, we apply numerical topology optimization to find the optimal material thickness distribution for both single and double panels. Two formulations of the optimization problem are employed: in the first one, we suppress the resonance dips in the sound transmission loss by simply pushing the system eigenfrequencies far away from the target frequency. In the second formulation, we directly maximize the sound transmission loss of the system at the target frequency. In the iterative design process, the panels are modelled by mechanical plate finite elements. For double panels, the vibro-acoustic coupling between the panels and the internal air cavity, which is modelled analytically, is accounted for. The sound insulation properties are evaluated by transmission loss computations through hybrid Deterministic-Statistical Energy Analysis (Det-SEA) simulations. The method is applied considering different target frequencies in the audible range and focusing on practically relevant design cases. For both single PMMA panels and double glazing panels, it is demonstrated how a non-uniform thickness distribution allows for significant transmission loss improvements close to the target frequency, that are in the range of 5-15 dB with respect to uniform panels with the same mass. [ABSTRACT FROM AUTHOR]

The Danish standard DS 490:2018 "Akustik - Lydklassifikation af boliger" *1, translated to "Acoustics - Acoustic Classification of Dwellings" relates to many acoustical parameters, and "Noise from ventilation" is now being tested in real life in the Danish "Voluntary sustainability classification" (called FBK *6). The Danish building regulation *2 state a sound level limit in dwellings from all kinds of technical systems at 30 dB(A), equal to the Acoustical class C, comparable with the limit in several countries. Research shows *3 that 30 dB(A) does not ensure acoustic satisfying comfort for all people. The FBK has chosen to lower the noise limit to 25 dB(A), equal to acoustical class B. We need to improve the ventilation systems to reach such lower level of sound emission, and we must be able to measure it implemented in dwellings. This paper describes some methods and in situ experience fighting background noise problems caused by activities and equipment around and in the dwelling, as well as in the measurement systems. A proposal for measuring closer to the ventilation armature and convert data to the prescribed position larger distance is described ant tested. The goal is: Measure and document low noise without a high cost in time and money, which could be a barrier for implementing lower noise levels in dwellings. [ABSTRACT FROM AUTHOR]

Neglecting turbulent scattering when modeling sound propagation in an upwardly refracting atmosphere leads to the prediction of unrealistically low sound pressure levels. Engineering models then typically impose a distance independent constant value for the sound pressure level relative to free field propagation. However, such an approach neglects the strong temporal variability in the sound pressure level observed in the acoustic shadow zone due to the scattering phenomenon. A modeling framework is presented to account for the effect of such scattering contributions, showing that the level variations might be as large as 20 dB in such zones. An approach to feed the model with the necessary turbulence input data is discussed as well. The engineering type scattering model further shows to be in line with more advanced but highly time-consuming predictions of outdoor sound propagation in upwardly refracting and scattering atmospheric boundary layers. This work contributes to more accurately predicting long-term sound pressure levels outdoors, also in situations where low levels might be of interest, e.g. near wind turbines. [ABSTRACT FROM AUTHOR]

This work aims at studying the mechanical and acoustic behaviours of a new bio-based porous epoxy resin obtained by a "green" adapted combination of the cationic photopolymerization and the porogen leaching technique. This new kind of material generally possesses interconnected complex morphology and it would be useful to consider this feature in a model. In this study, the effective properties of the material were estimated by using the asymptotic homogenization method. Four types of ordered pore arrangements together with systematic variations of the porosity and the pore size have been studied. Based on the results of these investigations, a subtle relation between the microstructure and mechanical/acoustic properties has been established. The estimated equivalent dynamic density and equivalent dynamic bulk modulus were compared with experimental results obtained by conducting the three-microphone impedance tube testing. The processing parameters of material elaboration could be adjusted so that the obtained porous material would possess the best sound absorption performance. [ABSTRACT FROM AUTHOR]

The dynamic and acoustic behaviour of the railway wheel is defined by its numerous vibration modes and natural frequencies. The modes whose contribution to the rolling noise radiation are predominant generally have 2 or more nodal diameters and appear above 2 kHz. The vibration due to these modes is decoupled from the rest of the wheelset, allowing the wheel to be treated separately. The error produced in the wheel noise prediction by this treatment appears at the low and medium frequencies and is negligible since the wheel emission occurs mainly at the high frequency range. However, given the dynamic coupling between the wheel and track, the changes in the dynamics of the former affect the latter, whose radiation is predominantly in the low and medium frequency range. Therefore, in order to correctly study both elements, it is necessary to include the contribution of the rest of the wheelset in the wheel response. In this work, this contribution is introduced through an analytical approach considering the rigid body motion of the wheelset and a benchmarking against an equivalent numerical formulation is carried out for validation purposes. In addition, the inertial effects associated with the rotation under straight circulation conditions are considered. [ABSTRACT FROM AUTHOR]

Tranquil environments are considered quiet, peaceful places where people can get away from everyday life, and for many years the University of Bradford's Tranquillity Rating Prediction Tool (TRAPT) has been used to successfully predict the perceived tranquillity of outdoor spaces as a function of their auditory and visual modalities. The Warren, Hull, established 1983, is a citywide free project for marginalised and vulnerable young people aged 14-25 that helps to encourage and support them to take control of their lives and futures by engaging them in all of the decision-making that has impact upon the strategic and day to day running of project. Staff at The Warren have noticed that the young people often gather around a large public fountain to socialise and relax; the same fountain is due to undergo major work in 2022 and will be sectioned off from the general public for months. This paper addresses the challenges associated with bringing tranquillity indoors via considered and experimental application of the TRAPT to indoor spaces, and via empowerment of the young people to introduce tranquil auditory and visual changes to multiple spaces in The Warren. [ABSTRACT FROM AUTHOR]

The two transverse motions of the string in planes parallel and perpendicular to the soundboard are believed to contribute to some of the characteristic effects of piano tones. In this work we aim to model the coupling between a single string and soundboard, considering the two transverse motions. A stiff string model is coupled to the bridge of the soundboard. Modelling approaches are presented in both frequency and time domain, using mobility coupling and state-space equations, respectively. For time domain modelling, the soundboard mobilities are approximated by lumped elements, springs and dampers in this case. In the frequency domain model, the mobilities of the elongated string, detached from the bridge, corresponding to the transverse response to a transverse force, are the same in both directions and the coupling between them is neglected, while the soundboard mobilities are represented by a 2 matrix. The state-space model has the benefit of allowing inclusion of the non-linear hammer excitation. Although the frequency domain model can represent the linear characteristics of the coupling and give an insight into the importance of the cross-terms of the coupled mobility, it is the time domain model that is able to represent typical features of the interaction. [ABSTRACT FROM AUTHOR]

This paper presents an efficient method to predict underground railway-induced vibrations. The method uses the finite element method (FEM) to model the railway tunnel structure and the singular boundary method (SBM) to model the wave propagation in the surrounding soil. The FEM mesh and the distribution of SBM collocation points at the tunnel/soil interface are generated using an automatic meshing strategy. The presented method is one of the main components of VIBWAY, a user-friendly prediction tool to address railway-induced vibration problems. This paper presents three calculation examples in which the soil response due to forces applied on the tunnel structure are computed in terms of transfer functions. The results obtained for each one of the calculation examples are compared with those computed using a model based on a 2.5D FEM-BEM approach. The presented comparisons show that the proposed approach is a suitable strategy for predicting underground railway-induced vibrations, both in terms of accuracy and computational efficiency. Moreover, the use of an automatic meshing strategy and the SBM formulation not only eases the implementation of the approach but it also makes it easier to use, which is one of the key features of the VIBWAY tool. [ABSTRACT FROM AUTHOR]

In my laboratory, a new noise localization method, 'Double nearfield acoustic holography (DNAH) method' is being developed. This method aims for mechanical noise source localization of the low frequency noise under 100Hz. Formerly, the experimental results of speaker tests in laboratory environment is presented (4)(6). It shows the better experimental results compared with the conventional near-field acoustic holography method as a low frequency noise sources localization method. In this paper, the experimental results of low frequency noise localization for a motor scooter using DNAH method are presented. As an example of mechanical product, a 50cc scooter's low frequency noise are measured by DNAH method, and by conventional near-field acoustic holography (NAH) method. The experimental results are compared with the results of conventional holography method. By these experiments, it is proved that the developing DNAH method can detect the low frequency noise source location of mechanical products, even if the sound frequency is lower than 100Hz. [ABSTRACT FROM AUTHOR]

Many engineering structures consist of plates being periodically stiffened or loaded. Examples can be wooden joist floors, dry walls with wooden or metal beams, or metamaterials for increased sound insulation. Even though some of these structures are well known and thoroughly studied in the past, there lack prediction models that can handle both the finiteness and periodicity in a simple and accurate manner. In two previous attempts, the periodicity of the structure have been tried to be incorporated in a variational technique based on integral-differential equations of the fluid loaded plate, based on [J. Brunskog, JASA 132, 1482-1493, 2012]. These attempts have not worked well: they show a poor fit with measured data. In this paper, this issue is investigated again, and a different tactics is used to incorporate the periodicity, using space harmonics. In this way, the paper try to explain the previous misfit and improve the model. [ABSTRACT FROM AUTHOR]

The Acoustics, Ventilation, Overheating: Residential Design Guide[1] ("The AVO Guide") was launched by the Association of Noise Consultants and Institute of Acoustics in January 2020. It provides a methodology for assessing the adverse effect due to break-in of external transport noise through façade openings provided for the purpose of mitigating overheating. Figure 3-2 of the AVO Guide indicates qualitatively how the SOAEL (Significant Observed Adverse Effect Level) is expected to vary with the duration for which the 'overheating condition' occurs. However, no quantitative guidance regarding the dependence on duration is given. This study describes how the methodology used in the WHO Night Noise Guidance for Europe 2009[2] to evaluate outside-to-inside level difference can be extended to provide a quantitative definition of the SOAEL for transport noise affecting passively cooled residential bedrooms at night. A quantitative version of the AVO Guide Figure 3-2 is derived and presented. Comparison is made between the SOAEL values presented here and the duration/frequency independent values suggested in the recently published Approved Document Part O[3]. Commentary is provided regarding the urgent need for better availability of relevant information on the frequency of occurrence of window openings for residential buildings in use, as opposed to data generated by the dynamic thermal models produced to show compliance with CIBSE TM59[15] and/or Approved Document Part O. [ABSTRACT FROM AUTHOR]

Densification of cities is used because of numerous benefits and fits well with sustainable development. Densification can however lead to disadvantages, especially related to environmental noise. In this paper, we ask: is it possible to restrict disadvantages by balancing out these with benefits? Access to quiet areas in cities plays an important part here, due to benefits related to well-being and health for inhabitants. We will give an overview of Norwegian guidelines on environmental noise and how these are implemented. We look at the situation from the Norwegian Public Roads Administration's viewpoint and include the experiences from a consultant company. We present projects situated in Norway, a large country with a relatively low population density compared to most other European countries. However, access to quiet areas isn't optimal in the largest cities, which leads to problems related to environmental noise and densification. Our experience is that it's crucial to include noise assessment in the early stages of planning. Together we need to find a balance, where new roads and new dwelling areas can be realised without more negative than positive aspects. The final goal must be, that there is no paradox!. [ABSTRACT FROM AUTHOR]

Under the CNR (Italy) and RSE (Scotland) joint scientific cooperation agreement, the project deals with the development and enhancing understanding of the technical clashes and engineering solutions required to deliver net-zero outcomes across diverse construction systems both in new build and retrofit. This paper relates to the comparison between the two research groups about the acoustic and energy standards and low carbon measures in force in both countries. The sound insulation requirements and energy efficiency for residential buildings are mandatory in both Scotland and Italian building regulations. Sound insulation performance compliance is undertaken via on-site testing after completion of construction works. Importantly the specification for energy efficiency changes (and improvements) to the fabric of buildings often clash in terms of the material properties and performance functions for sound insulation. Thus, it is critically important for the specification changes in building materials for energy efficiency do not negatively impact noise and vibration sound insulation and vice versa. This can lead to non-compliance resulting in noise disturbance complaints by building occupants or loss of performance for energy efficiency. The paper characterizes some of the regulatory factors, clashes in material outcomes and recommends the importance of multi-factor knowledge across building performance measures. [ABSTRACT FROM AUTHOR]

Transfer path analysis (TPA) is a proven method for identifying critical structure-borne and airborne sound paths. The basic idea here is to divide the overall system into an exciting active component (source) and a passive component, e.g., the mechanical structure to be investigated, with their respective measurement points. By separating them, two independent systems are created, whereby on the one hand the excitation behavior can be characterized and on the other hand the transmission behavior can be assessed. Finally, it is checked whether both systems harmonize with each other or whether changes to the source or structure are necessary. The advantage here is the simple description as a black box without complex modeling. In this contribution, this systematic is applied to window regulator systems found in vehicle doors. The focus is on a hybrid approach between experimental and numerical transfer path analysis. For this purpose, the basic workflow of suitable TPA methods is discussed. This includes evaluation of the test rig, the calculation of the contact forces and the numerical analysis of the transfer paths. [ABSTRACT FROM AUTHOR]

This paper shows the consequences for urban planning and road construction, if the Danish guideline from noise from motorways is to be changed according to the WHO-guidelines from 2018. It shows comprehensive challenges for urban planning and construction of new roads. Today the Danish guideline is 58 dB Lden while WHO suggest 53 dB Lden. The paper shows the technical possibilities to reduce the noise according to the WHO-guidelines. The paper also shows, that the cost for noise reducing initiatives along motorways would triple, the forbidden planning zone for new housing along motorways would be doubled geographically and the profit for urban developers behind projects for new housing outside larger cities would disappear. [ABSTRACT FROM AUTHOR]

The goal of this study is to investigate the psychophysiological effects of traffic sounds in urban green spaces. The experiment took into account four traffic sounds: road, ordinary railway, high-speed train, and tram. The results revealed that traffic sounds had a considerable impact on both psychological and physiological responses. In terms of psychological responses, it was found that the peak sound level performed better than the corresponding sound level in assessing the psychological impact of traffic sounds. The noise type and noise level were found to have significant effects on the physiological impacts of traffic noises. The physiological response to high-speed train noise was considerably different from the other three traffic noises. The physiological effects of road traffic noise were discovered to be unrelated to the noise level. In the railway noise groups, however, the change in noise level was observed to cause have an impact on the participants' physiological indicators. [ABSTRACT FROM AUTHOR]

In recent years, high-intensity airborne ultrasound applied technology has been developed actively. Accordingly, there are concerns about the effects of sound wave exposure by high-intensity airborne ultrasound. The sound wave intensity is different near the entrance of the ear canal and near the eardrum, because the wavelength is short in the ultrasound region. Therefore, it is necessary to know accurately the sound pressure at the eardrum position in considering the effects of sound waves exposure by ultrasound. However, it is difficult to measure sound pressure near the eardrum with a probe microphone because it may damage the ear canal and eardrum. Against this background, we have studied the sound pressure characteristics inside and outside the ear canal when airborne ultrasound is exposed to the mannequin head (KEMAR) with a pseudo-ear canal created to imitate the dimensions of the human ear canal. And, we have attempted to estimate the sound pressure value near the eardrum using the sound pressure in the ear canal. In this report, we verified the sound field inside and outside the ear canal and the sound pressure near the eardrum, when ultrasound (frequency:20 kHz) were irradiated to the mannequin head. [ABSTRACT FROM AUTHOR]

There are four inherent problems when predicting the airborne sound insulation of cross-laminated timber (CLT) plates. (1) The internal loss factor of wood products is high and therefore difficult to measure using the structural reverberation time technique. (2) Solid wood is a low-density building material compared to reinforced concrete or masonry construction. (3) Timber is orthotropic. (4) Orthotropic material properties include low shear moduli. CLT plates, similarly to thick masonry or concrete plates, exhibit thick plate characteristics in the high frequency range (f>1600Hz). The high frequency sound insulation data of nine plates is examined. Transitions to a thick plate seem to occur in all measurements. However, a clearly observable plateau is only visible for six of the nine plates. Simple methods are applied to extract information about the CLT plates from this high frequency (f>1600Hz) measured data. The data extracted from the plate is compared to typical values for equivalent isotropic plates, where the elastic modulus is assumed to be. The results are discussed in the context of laboratory measurement of sound insulation. [ABSTRACT FROM AUTHOR]

Road traffic noise accounts for the majority of perceived urban environmental noise and has important health consequences. The rolling noise of vehicle tyres is a major contributor to perceived road noise. The tread pattern of light vehicle tyres is already designed to minimize the amplitude of the noise emitted, but this is not the case for heavy vehicles. The European LEONT project aims to minimize the nuisance of heavy vehicle tyres, especially noise. Prior to a study of the effects of tyre noise on sleep, an experiment was conducted to determine the timbre parameters of such noise. The data set used was obtained by a series of recordings on a standardized track using tyres of various sizes. These stimuli were presented to headphones in a free sorting task. The poster will show the results of this experiment, including the correlations between acoustic parameters and perceptual space structure determined from the groups formed by the participants. [ABSTRACT FROM AUTHOR]

Experimental results showed that configuring different baffles (a regular baffle, a single- or doublelayer perforated plate and a Helmholtz resonator) in the plenum has an impact on the self-excited oscillation in annular combustor. In this paper, a 2D low-order network model is proposed to describe this phenomenon and predict the modal frequencies and growth rates of longitudinal and circumferential thermoacoustic modes for annular combustor with different baffles. In the plenum, only the circumferential acoustic propagation and the influence of baffles on it are accounted for as the longitudinal geometry size is much smaller than the acoustic wavelength of the longitudinal mode. Pure longitudinal acoustic propagation is considered in burners and both longitudinal and circumferential ones are accounted for in the combustion chamber. These three modules are connected by jump conditions. Compared with the experimental results, Baffles using Helmholtz resonators feature the best damping performance for specific modes. The circumferential mode is converted to two unfolded non-degenerate modes when configuring perforated plates baffles. And these two modes are orthogonal to each other. [ABSTRACT FROM AUTHOR]

Acoustic noise barriers based on sonic crystals constitute one of the most promising innovative bets of recent years in the field of environmental noise control. Sonic crystals are defined as metamaterials formed by periodic arrays of acoustic rigid scatterers embedded in a fluid (usually air). Furthermore, Helmholtz resonators can be added with the purpose of increasing the acoustic isolation of the barrier. Helmholtz resonances and multiple scattering are both noise control mechanisms of the sonic crystal noise barrier (SCNB). During the last decades several authors have different techniques to optimize the performance of these devices showing its huge potential. In this work we present new strategies with Particle Swarm Optimization in order to improve the performances of the approaches presented in the related literature. [ABSTRACT FROM AUTHOR]

This paper examines the issues that could arise regarding the implementation of noise policy in the context of the need and desire to deal with the effects of climate change. Is it going to be necessary to compromise the standards used or implied in noise policy in order to enable measures to tackle climate change to be put in place? Based on the author's extensive experience of developing and implementing noise management policy, this paper will consider how the pressures of tackling climate change could impinge on the outcomes that should be sought through noise management policy. The paper will consider the various types of noise policy that have and do exist and explore the issues that might now have to be addressed in order to secure a more sustainable future. [ABSTRACT FROM AUTHOR]

Due to the recent high speed of railway, noise and vibration generated during operation has emerged as a major social problem. Specially, the internal noise of railway varies depending on various operating conditions such as speed, vehicle crossings, and tunnel entry, and has a great effect on the riding comfort of passengers. In this study, an evaluation method for binaural noise of train pass-by noise and a simple wave field model which can reflect the Doppler effect are examined. To reflect the binaural characteristics of train pass-by noise, binaural measurements were conducted for several types of train, different measurement distances and various measurement angles. The annoyances of measured binaural noises were analyzed using conventional sound pressure level, psychoacoustic metrics, and their rate of change. Also, the noise emitted from high-speed railways was measured and characterized. By its analysis result, moving sounds were synthesized considering an initial frequency and a frequency shift. The synthesized sounds were convolved to reflect binaural condition. Auditory experiments were conducted using the synthesized moving sound stimuli, and the effects of the Doppler frequency shift on annoyance of moving sound sources were obtained. [ABSTRACT FROM AUTHOR]

The aim of this work is to manage adverse environmental impacts from long-range blast noise. The work was carried out as part of ongoing research at the DNV Spadeadam Testing and Research site (STaR). STaR carries out crucial major hazards work including improving safety concerns within industry decarbonization sectors and government agencies. The site performs a variety of explosives testing, resulting in environmental blast noise at off-site residential locations. The site is surrounded by complex topography, with terrain featuring rangedependent ground impedance and thermal properties which in turn effects the local meteorology. While accurately modelling blast wave propagation through such environments using computationally expensive methods is often attempted, the required complex and rapidly varying meteorological data are not effectively available. To address this deficiency, a datadriven heuristic method is proposed for the prediction of blast noise levels at several sensitive receivers ranging from 4-14km. The model is generated from a dataset of off-site blast noise measurements, correlated with a multivariate array of available meteorological data. A preliminary analysis is undertaken to make observations on the atmospheric features that are most influential on measured noise levels. It is concluded that useful predictions of the likely range of peak sound pressure levels over time scales from an hour to a number of days can be obtained using this heuristic method. Further measurements of blast noise, correlated with measured atmospheric conditions, are proposed to improve the performance of the model. [ABSTRACT FROM AUTHOR]

Most of the sound quality evaluation methods for loudspeaker are based on physical evaluation and subjective evaluation. In the physical evaluation, we focus on the peak sound pressure and the rise speed. In the subjective evaluation, the sound quality is evaluated by the subjective evaluation experiment using the sound quality evaluation word. However, it's difficult for people who don't have professional knowledge in the field of acoustics to judge the performance of a loudspeaker from these evaluation methods. In addition, according to the engineers of a speaker manufacturer, the difference of the sound quality of the loudspeaker may affect the movement and motivation of the game. In this study, aims to evaluate the sound quality of loudspeaker objectively from a new point of view. In order to clarify whether the difference of the sound quality of the loudspeaker affects the movement, the movement analysis using OpenPose was carried out. As a result, it was found that the complicated motion was not likely to be affected by the difference of the sound quality of the loudspeaker. However, the results suggested that simple and familiar actions may be affected by the difference in loudspeaker sound quality. [ABSTRACT FROM AUTHOR]

We investigated the azimuth angle characteristics of head related transfer function (HRTF) at very high frequency region using two kinds of head and torso simulators (HATS). In the measurement of hearing thresholds, there are two ways using a headphone or a loudspeaker. In general, it will be carried out using a loudspeaker because sound pressure calibration and measurement are simple. However, the hearing threshold which measured using a loudspeaker at very high frequency region may contain some errors because sound pressure level (SPL) reaching the ear are seriously affected by a small movement of the head. Also, the SPL near the pinna seriously depends on both shapes of a pinna and a head because excess attenuation by diffraction of VHF sound is very large. To provide assurance for the accuracy measurement of hearing threshold, it is important to make clear the relationship between the SPL and shape of head and/or ear. In this paper, we reported the HRTFs calculated from the SPLs measured at three different positions of left ear - a tragus, an auricle and an eardrum and discussed the influence of head and/or ear of HATS from the azimuth angle characteristics of these HRTFs. [ABSTRACT FROM AUTHOR]

In the field of human detection using acoustic arrays, the design of beamforming and detection algorithms is of vital importance. Evidently, the acoustic echo is directly dependent on the ergonomic characteristics of the people, as well as on the clothes they are wearing. Traditional techniques use a large set of people to characterize the system and evaluate the detection and false alarm probabilities. This work proposes a different approach, where a reduced set of people is selected and a cluster of points with their ergonomic data is obtained by means of a 2D LIDAR. From this data and using a classical reflection model, the signals that would be received in an acoustic array are calculated and, using beamforming techniques, the 3D acoustic image is obtained. The work compares these synthesized acoustic images with real acoustic ones. [ABSTRACT FROM AUTHOR]

The development of wind energy is accompanied by an increase in the number of people whose workplaces and/or places of residence are located near wind farms as well as is accompanied by numerous questions about the influence of wind farms on humans. Among the factors related to the operation of wind farms, wind turbine noise has to be seen as a source of annoyance for both people living and working near wind farms. A test bench to conduct noise annoyance tests of different types of wind turbine noise in laboratory conditions has been developed at the Central Institute for Labour Protection - National Research Institute. The test bench is based on a multi-channel sound reproducing system using the DANTE network and is compiled in the acoustic test chamber. The test bench consists of 18 speakers (including studio monitors and woofers) and a laboratory source of infrasound. During exposure to different virtual acoustic environments, representing different wind turbine noise, participants assessed wind turbine noise annoyance. The paper describes the test bench and the results of the studies concerning the assessment of wind turbine noise annoyance. [ABSTRACT FROM AUTHOR]

While traditional finite element based vibro-acoustic analysis of structures is done on stationary structures, in many occasions the structure under investigation is actually moving. To perform accurate finite element analysis on the vibro-acoustic performance of such structures requires the evaluation of a time-varying system, leading to several challenges, such as the selection of a strategy to update the mesh to the new configuration and an adequate time integration scheme that does not introduce large numerical artifacts. Additionally, the time-varying nature leads to an increase in computational complexity. In this paper a modeling strategy based on cut finite elements (cutFEM) is introduced that aims to tackle these challenges. The cutFEM approach can be seen as a fictitious domain approach in which the source is moving over a static mesh, cutting through elements where the actual source is located, using a level set description. The key advantage of this approach is that no re-meshing and/or mesh morphing is required. It is shown how both implicit and explicit time integration schemes can be used to propagate the solution while the source is moving. Additionally, several model order reduction strategies are compared to speed up the online evaluation of the reduced order model. [ABSTRACT FROM AUTHOR]

This conference paper deals with computational methods to determine the wavenumber spectrum of acoustic data measured by a phased microphone array. Such problems occur e.g. within the analysis of pressure fluctuations due to a turbulent boundary layer on a surface such as a wind-tunnel wall or the skin of an aircraft. The problem is closely related to the deconvolution of dirty beamforming maps in wavenumber domain, which seeks to determine the wavenumber spectrum by removing the influence of the shift-invariant point spread function from the beamforming result. Firstly, we recall how this task can be formulated as a minimization problem and then discuss a specific solver for this problem, provided by the framework of the generalized FISTA algorithm. The resulting method includes regularization with L1 and L2 penalties as well as a nonnegativity constraint. By exploiting convolutional structures, the computation can be further accelerated. Finally, the presented algorithmic framework is demonstrated with numerical examples. [ABSTRACT FROM AUTHOR]

A piezoelectric based stethoscope picks pressure fluctuations originating from the patient and the physician sides. This may include unwanted acoustic signals from the patient and the doctor sides of the stethoscope, which needs to be filtered either electronically or mechanically by appropriately designing the vibro-acoustic elements of the electronic stethoscope. This work intends to establish a mathematical model of the piezoelectric stethoscope. Initially, a multi-degrees of freedom vibration model of the electronic stethoscope is developed. The model is used to compute the response of the piezoelectric plate due to the pressure excitations on the input side and that due to the displacements of the connected mechanical elements in the stethoscope. Further, a two-port lumped parameter model of the piezoelectric composite plate is developed to compute the output voltage created by the displacement of the piezoceramic disc. Here, an axisymmetric plate model is used to find the displacement of the piezoelectric composite plate. Subsequently, the vibration and the lumped parameter piezoelectric models are combined to represent the fully-coupled vibro-acoustic characteristics of the piezoelectric stethoscope. The model is further used to predict the voltage output from the piezoelectric stethoscope for certain pressure excitation at the patient side. [ABSTRACT FROM AUTHOR]

When investigating the generation of rolling noise, profound knowledge of the tyre/road interaction is inevitable. Research projects addressing the road surface influence on the noise generation are commonly based on standardized road surface texture parameters e.g. mean profile depth or spectral analysis of surface profiles. Such quantities are calculated from line texture measurements or equally sized parts of 3D-road surface samples. AIT has recently developed a high-speed continuous 3D road surface texture scanner which provides heightened spatial information down to 60µm. This allows the determination of a multitude of additional parameters of road surface geometries. In this paper, statistical analyses of the variability of 3D texture parameters on real road sections, as well as basic statistical models to investigate correlations between texture parameters and coupled CPX measurements will be described. [ABSTRACT FROM AUTHOR]

Using parallel phase-shifting interferometry, we attempted to observe the sound waves around a high-speed moving sound source. The parallel phase-shifting interferometry can visualize the sound waves in the air based on the relationship between the air density modified by the sound pressure and the light phase of the PPSI laser. In our experiment, the sound source that emits 40 kHz sinusoidal sound was launched at 50 km/h or 100 km/h using RTRI's experimental testing facility. From the measurement, we succeeded in observing the frequency modulation caused by the Doppler effect. Furthermore, by applying three time-directional band-pass filters, frequency distributions around the high-speed moving source are clearly imaged. Therefore, the frequencies are modulated lower and higher at the backward and forward of the sound source, respectively. [ABSTRACT FROM AUTHOR]

In a research project on effects of noise on cognitive performance and wellbeing at work, several scales for subjective assessments with respect to the task execution are applied. The aim is to gain insight into how participants experience task processing in different background sound conditions. In the laboratory, participants worked on a proofreading task and a concentration task twice within an interval of around one week, once in a silent condition and once in one of various conditions with a background sound. In both sessions, participants were asked after each task to assess four aspects with respect to task processing: (1) experienced effort, (2) concentration, (3) performance and (4) disturbance by the acoustical condition. The scales range from 0 to 100. So far, one background sound (office noise) was applied. First, data were analysed regarding the differences between the assessments in the condition with and without background sound, separately for the two performance tasks. For both tasks, participants experienced significantly more effort, lower concentration and higher disturbance in the condition with background sound than in the silent condition. Once all sound conditions are completed, an analysis of the comparison between the groups with different background sound conditions will be conducted. [ABSTRACT FROM AUTHOR]