Impact Of Noise Research Articles

Acoustic aspects in the construction and upgrading of military firing ranges - Part 2

Military firing ranges are indispensable facilities to train armed forces in handling and use of small arms. In the past, such ranges were outdoor installations. Due to noise problems around some of these shooting ranges they will be replaced more and more by indoor shooting facilities, which increases the noise impact on the personnel. First, the design of shooting ranges must consider the internal and external firing safety. However, acoustics comes next. There are two different but equally important objectives. The facilities should be built in such a way that (1) the noise impact on the hearing of personnel and (2) the noise impact on the neighbourhood is as low as possible. The design of shooting ranges should already take these aspects into account during the planning phase. This article focusses on the topic of acoustic safety (1) and is divided into two parts. Part II: The second part of the article describes the practical application of the new directive, with its acoustic material and measurement requirements, based on a recent tendering procedure in which various companies were offered the opportunity to develop acoustic wall and ceiling systems for indoor shooting ranges as part of a so-called competitive dialog.

The design of listening tests for impact noise annoyance ratings

Noise annoyance is characterized by irritation, discomfort, disturbance or distraction. The evaluation of impact noise based on user response provides useful information about subjective auditory perception. These assessments are carried out by participants in listening tests under laboratory conditions, where participants usually rate the annoyance caused by different samples of impact noise. The question arises as to whether it is possible to gain a meaningful insight into the human inner life by evaluating only a single quality such as annoyance. Therefore, other qualities such as loudness, allowance limit or naturalness are also included in the rating procedure. In this paper we present the design of the listening test for impact noise annoyance and the corresponding selection of investigated qualities. It describes why they were selected and how the evaluation was carried out. It also describes how descriptive qualities have been used in other studies. The technical implementation of the listening procedure is presented and correlations between the ratings of the different qualities are discussed.

Recycled plastics based impact noise resilient layer development

Sustainability and the carbon footprint reduction is commonly associated with recycling and secondary use of materials, for example also in the building construction industry. For decades, experts have been dealing with this topic across the entire spectrum of the development of building structures. One of the areas where soft recycled materials find suitable application is the area of building acoustics with a focus on impact noise attenuation. This contribution focuses on resilient layers dedicated for lightweight floating floors. This type of flooring is very often used in the reconstruction of apartments in apartment buildings. There is usually no possibility to realize heavy floating floors or for static reasons or reasons of the structural height of rooms or door openings. The work focuses on the development of floor underlayer mats based on recycled material in several variants. These were experimentally compared with conventional materials used in practice as the so-called impact sound insulation layers under laminate floors in terms of improving the impact noise insulation as well as the dynamic stiffness and the loss factor.

Impact noise calculations of CLT constructions using finite element

Cross-laminated timber (CLT) consists of multiple glued layers of wood, which have perpendicular orientation with respect to adjacent layers, and it has become an important building material due to its light weight, strength, and sustainability. One problem with CLT constructions is the impact noise, which for a bare CLT floor is poor. There thus is a need for calculation tools that can predict impact noise level of such floor constructions. For composed constructions, finite element is a flexible and usable tool. However, to simulate real measurement scenarios, the force produced by the ISO tapping machine then needs to be estimated. This paper revisits this estimation and performs calculations of the impact noise level of a CLT floor, and compares this with measured results.

The impact of noise in intensive care units on the wellbeing of healthcare workers

This study aims to investigate the impacts of noise in intensive care units (ICUs) on the well-being of healthcare workers. To achieve this, a series of research activities were conducted. Firstly, noise monitoring was carried out at ICUs in China to explore the noise levels and sources. Secondly, a questionnaire survey was performed with ICU nurses to investigate the risk of voice disorders, utilising the Voice Handicap Index (VHI-30). Additionally, voice use of ICU nurses was monitored using a wearable microphone. Thirdly, the hearing of ICU nurses was assessed through Pure Tone Audiometry test (PTA) and Digits-In-Noise (DIN) test. Lastly, semi-structured interviews were conducted to explore how ICU nurses perceive and react to the noise in ICUs. This paper will present the outcomes of the aforementioned research.

The impact of a large airport on residents' quality of life and annoyance

A nearby large airport provides both positive and negative impact on surrounding communities. It can provide economic growth for a region near an airport, but also have a negative environmental and health-related impact with respect to aircraft induced noise exposure and air pollution. To study the impact of aircraft noise together with other aspects of air traffic in an airport region on the quality of life (QoL) and annoyance of residents in surrounding regions, a survey regarding nine QoL indicators was conducted for two Dutch communities. A comparison was made between one higher aircraft noise exposed community situated near Schiphol airport and one in Utrecht without a neighbouring airport and thus less exposed to aircraft noise. Results showed more aircraft noise-annoyed people living near the airport than people living further away. Using a Principle Component Analysis, the nine extracted factors supported previously theorized indicators defining QoL. Noticeable differences were found in neighborhood trouble, social contacts and aerospace perception between these two communities with the airport as main discriminator. Outcomes of this study help to develop a model to measure QoL and improve the understanding of the impact of noise exposure and other characteristics of a nearby airport on people's well-being.

Analysis of the underwater acoustic environment in the Catalan Shore: Badalona and Port of Barcelona cases in the framework of the Deuteronoise JPI-Oceans Project

Maritime traffic noise pollution is a significant concern for ocean's health and living organisms' welfare, particularly in European sea basins. Research has predominantly focused on vertebrates, linking noise pollution to hearing impairment, affecting their predator and prey detection, communication, and navigation. However, recent findings suggest that tunicates, marine invertebrates related to vertebrates, may also be susceptible to noise due to their similar acoustic and particle motion sensory organs. The JPI Oceans project, Deuteronoise, addresses this research gap by characterizing noise from maritime traffic in selected European sites, investigating the effects of noise on marine deuterostomes. In this paper, we introduce the pipeline and retrieval methods, followed by an analysis of the data collected from two contrasting locations: Port of Barcelona, noise polluted area, and Badalona, non-polluted one, focusing on the noise impact on Oikopleura dioica, a representative appendicularian tunicate. Initial laboratory analyses of recorded sounds have identified different vessel and sound features, providing distinction between the two sites. With this data analysis, we aim to bring valuable insights that will enhance our understanding of maritime noise pollution. This research not only advances our knowledge of the ecological consequences of noise pollution but also informs conservation strategies for vulnerable marine ecosystems.

Influence of the sound propagation models to predict far field wind turbine noise

During the development process of a wind farm, the noise impact on neighboring residents is of crucial importance to limit annoyance and comply with local regulations. In France, this assessment is carried out by modelling the propagation of sound from each wind turbine to residents. For wind farm owners, this phase will in fine define the operation of the wind farm and therefore its electricity production. However, there are major concerns and uncertainties during this modelling phase. A concrete example of the influence of the choice of propagation model on the production of a wind farm is presented, giving an idea of its economic impact. Comparisons of the impact of wind farm noise modelled by engineering models with measurements taken on wind farms in operation provide a better understanding of the choice of certain methods or parameters. Taken together, these observations suggest areas for further research and development, with the aim of perhaps defining a more restricted framework for the sound propagation modelling stage, in order to help operators predict wind farm noise more accurately.

The method to determination of the utilization of thrust reversers after landing based on noise measurements and analysis of its results

The use of powerful thrust reversers after landing often results in a noise impact on the area of surrounding the airport. The use of thrust reversers, while not necessarily a prerequisite for landing maneuvers, is sometimes a significant means of ensuring more safety for the pilot. For this reason, the magnitude of the thrust reversers, and the segment of the runway in which the reversers are used, vary widely. We have established a method to determination of the utilization and the strength of reverse thrust from noise measurements taken at several stations along the runway side. This report also describes an analysis of the results of the operational conditions of thrust reversers at a multitude of Japanese airports that were examined using the methodology.

Rooftop pools - a problem from an acoustic point of view: how to identify and solve it

There is no standard with specific methods for acoustic testing of rooftop swimming pools in Brazil. On the other hand, although the compatible requirement for impact noise from rooftop leisure environments is not the type of noise generated by swimming pools, it is a current requirement in the Brazilian performance standard. To study the subject, evaluate possible solutions and improve the state of the art, this article brings measurement results for impact noise in the same situation without and with the application of an acoustic solution. The study also presents sound pressure level and vibration measurements in an environment below a swimming pool after the application of the acoustic solution. Vibrations were measured as well in the pool structure and in the slab below, making it possible to identify the vibrational behavior of the pool. Measurements of impact noise took place in a situation where the pool is three floors above the last residential unit to verify the influence of technical slabs. With the measured values in the three situations, it was possible to identify the frequency range for which acoustic solutions should be designed for this type of source and to monitor the effectiveness of different solutions.

Annoyance evaluation of impact sounds on lightweight, concrete and cross-laminated timber floors - A comparative study

For people living in multi-unit residential buildings, neighbor noise and especially impact noise from neighbors, such as dropping objects or footsteps, can affect the quality of living of those who hear the noise. In order to support the inclusion of limits for impact noise in a future edition of the National Building Code of Canada, a project at the National Research Council of Canada has focused on the perceived annoyance from different types of impact sounds for various timber floor-ceiling assemblies. The results from listening experiments showed poor correlation between subjective ratings and objective single number metrics for impact noise due to persons walking without shoes. To extend this evaluation to a wider variety of floor-ceiling assembly types and to validate previous results, another listening experiment was conducted at the National Research Council. Annoyance ratings for ball drops, hammer impacts and footsteps on different lightweight, concrete and cross-laminated timber floor-ceiling assemblies were compared.

Application of Cadna/A software to the prediction of traffic noise on residential envelope sound insulation

The primary issue influencing residential structures' interior sound insulation environments is urban traffic noise. When choosing sound insulation for residential windows and doors, it is essential to consider the influence of road traffic noise. In conjunction with the examples, a three-dimensional simulation prediction model is created early on using Cadna/A software, and it is configured in accordance with the measured data of the road environmental noise to predict the sound pressure level of the outer surface of the residential building's enclosure structure at various locations and floors. This serves as a foundation for choosing the residential building's interior sound-insulated windows and doors as well as for the building's construction. In order to confirm that interior doors and windows are structurally sound-insulated, sound insulation measurements of typical residential sample buildings are made later in the building process.It offers some reference value for using Cadna/A in the assessment and forecasting of traffic noise's impact on the soundproofing of residential building envelopes.

Developing and testing systems for the attenuation of ships' machinery noise

With ships operating in areas including important marine biodiversity, it is crucial to understand the sources and characteristics of underwater noise and develop effective measures to mitigate underwater noise's impact on the environment. The underwater noise signature from a ship is usually dominated by machinery noise and propulsion engines at low speeds. Given the importance of onboard electrical power, diesel generators might continuously function (i.e., even when a ship is docked) and generate low-frequency underwater noise. Université de Sherbrooke (Sherbrooke, Canada) and Innovation Maritime (Rimouski, Canada) lead a collaborative work focusing on the means and methods for attenuating machinery noise. Two main research axes are considered. The first concerns the setup and validation of a small-scale platform that can be used to test noise reduction methods in a controlled water basin environment. The second research axis investigates passive, tunable, and possibly multi-resonant vibroacoustic solutions to attenuate machinery noise. These solutions mostly come as 3D-printed folded quarter-wave resonators following spiral or cantilever resonators. Acoustic resonators can also be embedded into a layer of sound-absorbing material to improve soundproofing properties at specific frequencies. The applications and scope of this work are finally put into perspective.

Toward the symbiosis and co-prosperity between Narita International Airport and the local community in line with airport capacity enhancement

Narita International Airport is working toward "Further capacity enhancement of Narita International Airport", and will be able to increase the annual departure and arrival capacity from the current 300,000 to 500,000 times by constructing Runway C, as well as the extension of Runway B. This report describes what kind of initiatives and measures Narita International Airport Corporation (NAA) takes in collaboration with the local municipalities and residents based on the basic idea that "Airport development is regional community development" including the efforts to investigate noise impact on the living environment, including health effects. Narita International Airport has been regarding its symbiosis measures, airport development, and regional development as a trinity and various efforts have been made. In addition, since the opening of the airport, NAA has taken detailed measures from various angles to address the problems stem from being an inland airport. This report describes the background to the implementation of the investigation of the impact of aircraft noise on the living environment, including the impact on health effects, at Narita International Airport. The technical aspects of the study will be presented in another report.

Effect of background noise and diffraction on localization of sound sources using distributed acoustic measurement equipment

This study is focused on the development of a system designed to pinpoint the positions of sound sources within a plane through the analysis of cross-correlated signals obtained from distributed microphones. Our investigation delved into assessing the impact of physical barriers and background noise on the accuracy of the proposed method for localizing sound sources. Prior research has demonstrated that measurements conducted within an anechoic chamber yield estimations accurate to within ±20 mm. When the signal-to-noise ratio of the target sound source is reduced by the background noise, the estimation is performed at the point of background noise generation. Furthermore, the introduction of physical barriers between the sound source and the microphones resulted in sound diffraction, thereby leading to estimation errors attributable to the varying lengths of diffraction paths. These findings underscore the importance of considering environmental factors in sound source localization endeavors. The estimation at Mic, where the sound-receiving level drops below -10 dB due to physical barriers, confirmed that the background noise source point is estimated as well as the background noise estimation error.

Assessing indoor and outdoor noise quality and associated health impacts at selected schools in Surat, India

An optimal ambient environment is crucial for healthy development, yet the excess of vehicles and inadequately planned educational infrastructures compromise cognitive growth in children. This study evaluates the impact of ambient noise on student cognition in five schools situated along city arterial and sub-arterial roads. A total of 717 students from grades 7, 8, 9, and 11 participated. Noise levels were measured in prevailing noisy conditions (PC) and controlled silence conditions (SC) within classrooms using the Kimo dB300 sound level meter. The observed differences in noise levels between PC and SC varied across grades, showing reductions of 4.7 ± 3.5 dB, 6.1 ± 0.7 dB, 6.7 ± 1.3 dB, and 4.4 ± 3.46 dB for grades 7, 8, 9, and 11, respectively. Statistical analyses revealed significant differences in the average noise levels under both conditions. Furthermore, cognitive task performance in PC and SC was significantly different, as evidenced by paired t-tests in tasks such as multiplication, word formation, reasoning, and sentence construction. Dimension reduction techniques identified room acoustics, task difficulty, speech intelligibility, mental deficiency, and annoyance as critical factors affecting learning abilities. Teachers reported that major impacts of noise include annoyance, sleeplessness, headache, and hearing impairment.

Predicting the impact of wind turbine noise: general overview and results of the PIBE project

The PIBE project aims to improve wind turbine noise prediction methods and to explore new solutions for noise reduction. This five years project brought together French experts in aeroacoustics, sound propagation, experimental noise characterization and wind engineering, and was structured around three work packages. The first one aimed to study amplitude modulation phenomena and focused particularly the characterization of dynamic stall noise. Specific aerodynamic and acoustic measurements were carried out in a wind tunnel, showing the influence of several stall regimes on noise production. The second work package focused on quantifying the uncertainties of noise prediction methods. It developed an open-access online application (WindTUNE) that quantifies uncertainties on noise prediction of a wind farm, and a parametric and uncertainties calculation tool for the engineering application Code-TYMPAN. This axe also produced an open-access database of a 400 days campaign of meteorological and acoustical measurements around a wind farm. The last work package investigated new noise reduction devices using blades with modified leading and/or trailing edges. The efficiency of the solutions were characterized in a wind tunnel, both acoustically and aerodynamically. The paper presents the main results obtained at the end of the project.

Noise reduction design of new residential buildings along urban roads-taking a residential district in Foshan as an example

Taking a residential district in Foshan along the city road as an example, the impact of urban road traffic noise on it is studied. Firstly, the data is monitored in the noise field, then three-dimensional simulation models of residential buildings and road distribution are established in Cadna/A software, and noise simulation prediction is carried out according to the actual situation and relevant norms and standards. The predicted noise values of the exterior surface of residential buildings are obtained, which has exceeded the permissible interior noise level for residential buildings. By comparing the application effects of noise reduction measures in buildings, the noise reduction design scheme of new residential buildings along urban roads is finally proposed: the sound insulation doors and windows that meet the requirements are adopted. After the completion of the house, the indoor background noise and the sound insulation performance of the doors and windows are measured. The measured results show that the selection of sound insulation doors and windows is suitable and the indoor noise environment meets the design requirements of noise reduction. The results are helpful to provide technical reference for the noise reduction design and renovation of other residential buildings along urban roads.

Conscious walk: integrating soundscape, biodiversity, and air quality metrics for holistic urban environmental assessment

The impact of environmental noise, poor biodiversity, and air pollution on urban populations poses a significant challenge to public health. Addressing these concerns requires a comprehensive approach that considers the perceptual experiences of citizens and objective environmental data. The Conscious Walks introduce a hybrid methodology designed to address the perceptive impact of citizens on their environment. Conscious Walks are citizen-science participative projects that combine the active involvement of citizens with scientific data collection. Implemented and tested in Barcelona, Conscious Walks provide a unique opportunity to assess urban soundscapes, and this contribution specifically evaluates the soundscapes of the Ciutadella Park in Barcelona for three consecutive years. The gathered data is carefully cross-referenced with information on air quality and biodiversity obtained during the walks. The novelty of this research lies in the development of integrated indicators that comprehensively capture the interplay between biodiversity, noise pollution, and air pollution. These indicators provide an understanding of urban environmental quality, offering valuable insights for sustainable urban planning and policy-making. The results presented in this contribution underscore the significance of adopting holistic methodologies to address the complex challenges posed by urban environments, emphasizing the need for integrated indicators in assessing the multifaceted aspects of urban sustainability.

Development of integrated noise analysis systems for ship propellers considering hull wake

Recently, the requirements for underwater radiated noise (URN) reductions in ships have become significant issues, driven by concerns over the impact of naval vessel performance and noise on marine ecosystems. The majority of URN generated from ships is attributed to the propeller. This study developed the integrated noise analysis systems that predict and analyze all the significant noises generated from the propellers, considering the hull wake. Since each type of noise has different sources and mechanisms, it is essential to analyze all types of noise to evaluate the propeller noise performances comprehensively. The model was developed for cavitation noise by compression and expansion motion of bubbles to evaluate the radiated noise. For non-cavitation noise, a noise model on the frequency domain was derived to cover the noise generated by changes in the wake. The unsteady pressure on the rotating blade was obtained using flow fields and wall pressure spectrum, extending to high frequencies. The developed system provides a valuable tool for propeller optimization designs by minimizing URN while considering the shape of the hull and appendages.