Acoustic Environment Research Articles

Measurement of sound perception to improve the performance of military ships

The performance of military ships relies on the performance of equipment and operators. Acoustic performance of military ships consists of: - the acoustic discretion of the vessel, allowing a strategical advantage in the event of a threat (more specifically: noise and vibrations management of ship sources); - the acoustic comfort of the operators in the ship, allowing better oral communication, better perception of safety alarms and a better focus. These effects can reduce time loss, and prevent operators from making errors. It is therefore important to manage the acoustic environment on board throughout the design process, in order to ensure both the acoustic discretion of the ship and the performance of its operators on board. For several years, Naval Group is interested in optimizing the performance of the operators, coupling both acoustic and visual perceptions through virtual reality (VR). This congress is an opportunity to expose recent works on acoustic perception in a ship. Our results are based on both numerical simulations and experimental measurements.

Relationship between greenery and the health of Madrid's citizens

The increase in parks will be one of the interventions in future cities to reduce pollution and enhance the quality of life. However, it is crucial to identify the variables within parks that have the most significant impact on well-being and health, given the substantial limitation of urban space. Different parks in Madrid were analyzed in this study, and simultaneously with the recording of environmental variables, their users were surveyed. The study's hypothesis aimed to determine whether the activities carried out in the parks have a greater impact on health than their mere presence. The quality of parks is an influential factor in these relationships; therefore, the quality of the acoustic environment was considered. The results indicate that the quality of the soundscape is a significant factor in the development of various activities and the overall perception of the park, making it a variable to consider in the design and improvement of the quality of green spaces. Greenery visibility is significantly related to the perception of health status, but this relationship is less intense than that provided by frequent activities in these green spaces such as walking and relaxation.

On the effect of indoor acoustic conditions in performing cognitive tests in primary school

The quality of the acoustic environment is essential to foster learning as students learn by listening to the teacher. Prolonged exposure to noise during critical learning periods at school can impair development and have a lifelong effect on academic achievement. This is why the problem of noise is of concern in learning environments such as schools. Poor acoustic quality leads to increased cognitive effort that is associated with greater difficulty in processing and remembering information in the short and long term. Preliminary results from the administration of neuropsychological tests under quiet and noise conditions only partially supported the hypothesis that noise negatively impacts children's cognitive performance. In fact, only in one of the two monitored schools the children's performance was affected by the presence of noise during the execution of the tests. In this paper, new results obtained from the correlation between the acoustic parameters and the children's responses to the cognitive load assessment questionnaire are presented to confirm the validity of the hypotheses.

Dual-stream Noise and Speech Information Perception based Speech Enhancement

In real-world scenarios, dynamic ambient noise often degrades speech quality, highlighting the need for advanced speech enhancement techniques. Traditional methods, which rely on static embeddings as auxiliary features, struggle to address the complexities of varying noise conditions. To overcome this, we propose a Dual-stream Noise and Speech Information Perception (DNSIP) approach that dynamically detects and processes both noise and speech through innovative information extraction and suppression mechanisms. Initially, non-speech segments predominantly contain environmental noise, while speech segments carry information about the intended speaker. To handle this dynamic nature, real-time voice activity detection (VAD) is employed to accurately differentiate between speech and noise components. Building on VAD estimates, we propose an innovative information extraction framework that selectively extracts relevant noise and speech features from the noisy input, establishing a dual-stream network for concurrent noise and speech learning. To account for the temporal and spectral variability of noise and speech, a frequency-sequence attention mechanism is integrated, enhancing the model’s ability to learn contextual and spectral dependencies. Additionally, an information suppression module is introduced to minimize cross-stream interference by attenuating noise within the speech stream and suppressing speech content within the noise stream. The derived noise and speech spectrograms are then utilized to formulate a minimum mean square error log-spectral amplitude (MMSE-LSA) estimator for robust speech enhancement. Experimental evaluations on the WSJ0 and VCTK+DEMAND datasets demonstrate that our DNSIP approach surpasses existing state-of-the-art methods, underscoring its efficacy in challenging acoustic environments.

Assessment of the acoustic environments in dementia care units: a case study

Dementia patients represent a particularly vulnerable group of people that are easily affected by their surroundings. Minor disturbances can lead to challenging behavior for the caregiving staff. Sensory stimulation is a critical factor in the treatment of these patients. At the same time, there is a challenge associated with it overstimulation as this can lead to social isolation, known as a factor that increases the risk of developing a dementia diagnosis. Therefore, a tailored sound environments is important to promote an inclusive environment for the patients to increase their well being and life quality. This study aims to discover the acoustical conditions at dementia care units in two hospitals, examine the impact of acoustic environment on patients and provide feedback about the existing standards and regulations for such buildings. In-depth interviews and measurements are combined to conduct both qualitative and quantitative feedback from the actual environment and users. The results can be used to develop acoustical design criteria for dementia units in the future.

Optimization and adjustment of indoor acoustic environment of theatre - Taking Guangzhou design capital-design hall theatre as an example

Theater is a place for all kinds of performing arts, and its design and function are usually diversified to meet the needs of different types of performances. odeon software is calculated with the sound source method and sound line tracking method, and adopts the Lambert scattering algorithm to calculate the sound diffusion, so that the simulation process is more and more realistic, and the calculated results are closer to the actual measured values. using odeon software to simulate the Using ODEON software to simulate the Guangzhou Design Capital - Design Hall Theater, according to the simulation results, the reverberation time is relatively short and other issues such as corresponding adjustments and recommendations, to give the Guangzhou Design Capital - Design Hall Theater indoor sound-absorbing material layout plan.

Sound prediction of an electric car using numerical simulation and sound synthesis techniques

The automotive industry's transition to electrification raises new challenges to maintain a comfortable acoustics environment both inside and outside the car. This paper presents an innovative way to make an early prediction of the overall sound of a vehicle at driver's ear by mixing noise sources that can be simulated and noise sources measured at component level. This hybrid approach combining Test and Simulation data helps define acoustic and vibration specifications at component level and take decisions on design strategies. For instance, the mounting method of the Electric motor to the body can be decided using a combination of Electric motor numerical simulation and Rolling noise sound synthesis techniques. Realistic signals could be generated and compared with sound quality metrics to choose the best vibration isolation strategy.

Characterizing urban acoustic environments by clustering sensor node measurements

Equivalent sound pressure levels have been widely used to assess the impact of the sonic environment on persons. At the same time, it has been demonstrated that sound sensor networks allow to extract a wealth of information about the living environment. Nevertheless it has not been clearly demonstrated how to summarize this information. To this end, we used advanced non-linear clustering methods to group 15-minute sound environments based on a wide range of classical acoustic indicators such as peak levels, statistical levels, spectral center of gravity. Machine learning methods identifying the sound sources that are present based on 1/3 octave band levels measured at 125 msec interval, are then used to better understand why these clusters emerge. The methodology is applied to 150 bedroom window measurements gathered in the Equal-Life project. Preliminary results show that groups of pre-school children with specific cognitive development and mental health are related to different diurnal patterns of sound environment clusters. These results can be interpreted in the larger context of living environments extracted from environmental sound sensing networks.

Exploring perception and immersive experience of visually impaired people in 360° video and 3D ambisonic audio

For a long time, immersive experiences have been designed with primarily sighted users in mind. However, recent advancements open exciting possibilities for expanding this realm to include individuals with visual impairments such as Cataracts, Glaucoma, and Severe low visual. One promising avenue lies in utilizing 360-degree videos with 3D Ambisonic audio recordings to create immersive experiences specifically tailored to their unique perceptual abilities. In this context, this preliminary study investigates audio-visual perception and presence of visually impaired people (VIP) in immersive reality (IR) environments, by applying 360-degree video and 3D Ambisonic audio recordings in three different environments of a public park "Parking area, Green space, and Playground". The methodological approach of this study is based on a comparative study between sighted (SIG) and visually impaired people (VIP), by conducting questionnaires such as the presence questionnaire and the emotional salience questionnaire. The findings show that both categories can experience the same presence within the IR environment with a difference in the evaluation of the acoustic environment, where the visually impaired show a greater influence on mechanical sounds. By designing inclusive experiences for all, IR has the potential to be equally engaging and immersive for everyone, regardless of sight.

A deep learning approach to predicting UAV sound affect

The most prevalent method by which the impact of an acoustic environment upon people is assessed is the `environmental noise' approach, in which the sounds are quantified based entirely on their recorded weighted sound pressure levels. This does not account, however, for the character of sounds outside of their loudness. Objective metrics such as psychoacoustic annoyance have been developed to attempt to rectify this, however this is still heavily weighted towards loudness as the most important factor and may not provide a good estimate for subjective perceived annoyance for all sound sources, including unconventional aircraft such as unmanned aerial vehicles (UAVs). Here we present a novel method using a convolutional neural network (CNN) to predict perceived annoyance directly from mel-spectrograms derived from recorded audio featuring both traditional and unconventional aircraft sources. The network is trained and tested using data collated from five separate listening tests, and is shown to outperform conventional regression models based on psychoacoustic annoyance as a predictor of perceived annoyance. The time-frequency resolution of the calculated mel-spectrograms is shown to be a key factor in performance.

Reshaping workspace soundscapes: An in-depth analysis of ISO 22955 compliance and its influence on acoustic comfort and wellbeing - a case study

The prevalence of hybrid office landscapes is on the rise, eliciting concerns among users primarily due to noise and the challenge of balancing two conflicting acoustic activities: oral communication and concentrated individual work. This study investigates the interplay between acoustic comfort and wellbeing in an office setting, utilizing evidence-based data gathered through occupant surveys before and after a comprehensive renovation. Prior to the renovation, room acoustic calculations were performed to assess compliance with the acoustic parameters from the ISO 22955:2021: "Acoustic quality of open office spaces". The office was transformed, guided by a human-centric approach, from a predominantly enclosed layout into one that incorporates a blend of open-plan areas and closed rooms designed for meetings, concentrated work and phone calls. Room acoustic measurements were taken before and after the renovation that confirm compliance with ISO 22955. The results of the questionnaire indicate improvements in concentration, decision-making and contemplation, which corresponds well with acoustic parameter values achieved. Nevertheless, "disturbance of nearby conversations" was not reduced as expected. The research delves into the connection between the indoor acoustic environment and subjective experiences of health, well-being, and responses to noise disturbances, emphasizing the need for tailored acoustic design to optimize overall workplace experiences.

Design solutions to optimise acoustic requirements for specific work activities in open-plan offices

A high level of concentration is required in open-plan offices, which entails an optimized acoustic environment. The aim is to create a fit-employee environment in which speech privacy is guaranteed without compromising the sense of cooperation among occupants. The purpose of this study is to investigate the design solutions which optimize the acoustic requirements of ISO 3382-3 for a specific work activity defined in ISO 22955, such as non-collaborative work, collaborative work between people and mixed between collaborative and non-collaborative. The case study is one open-plan office occupied by 12 workers, which was not compliant with the standard. Acoustic measurements were used to calibrate the acoustic model in the Odeon software. Two screen and cubicle heights, three types of ceilings and two wall absorption configurations have been tested in a matrix of solutions for the office in the simulation model. This allowed us to investigate the design solutions that guarantee optimal values for the acoustical parameters chosen for each specific activity.

Robotic arm, 3D vision and geometric matching for an efficient implementation of inverse Patch Transfer Function method

The inverse patch transfer function method was developed to reconstruct the acoustic fields (velocity, pressure, intensity) at the surface of a vibrating source with a complex geometry using the concept of a virtual acoustic domain. This method can be used to manage sources with complex shapes in a non-anechoic acoustic environment, even in the presence of masking objects. However, this method is quite demanding experimentally as it requires a large number of measurement positions with good spatial positioning accuracy. This article presents a dedicated experimental platform developed to simplify and automate the entire measurement process. First, a 3D camera placed on a robotic arm constructs a point cloud characterising the source and its environment. Using a geometric matching algorithm, the CAD of the object under test is detected in the cloud of points, enabling the different coordinate systems (CAD, robot and physical part) to be matched. Secondly, the measurement points required to apply iPTF can be defined directly in the CAD and reproduced in near-real time on the test rig, regardless of the type of antenna used, providing an efficient means of applying iPTF and opening the way to many advanced applications.

Sounding São Paulo: exploring the acoustic environment of Vai-Vai Samba School

In the study, a broader approach to urban planning was explored, surpassing traditional noise analyses that often neglect subjective aspects. The focus centered on the soundscape of the Vai-Vai Samba School, a cultural landmark in São Paulo's Bixiga neighborhood, renowned for its Afro-Brazilian heritage since its establishment in 1930. Following ISO 12913 guidelines, measurements of sound pressure level, binaural analyses for psychoacoustic parameters, and interviews with attendees were conducted to comprehend sound sources, perceived quality, and perceptions of the surrounding sound environment. By correlating quantitative and qualitative data, the interaction between objective and subjective analyses was examined. This study offers valuable insights for urban planning, underlining the significance of considering history and culture when addressing soundscape matters.

Interplay of perception, behavior, and sound: analyzing music activities in urban open spaces

This study conducted an exploratory investigation into the impacts of music activities in urban open spaces, focusing on the interrelations between perception, behavior, and A-weighted sound pressure levels (LAeq) associated with these activities. Utilizing observational and questionnaire methods, the research categorized music activities into dynamic (e.g., dancing) and static (e.g., singing) types. It revealed significant differences in participant numbers, age demographics, and LAeq between the two categories. Results indicated that dynamic music activities typically attracted an older participant and had lower LAeq than static activities. However, participants in dynamic activities reported lower levels of sound comfort and spatial satisfaction. Within dynamic music activities, a negative correlation was found between LAeq and sound comfort, whereas no significant correlation was observed in static music activities. Additionally, participant numbers in dynamic activities showed no relation to sound pressure levels, which increased with the activity area. Conversely, in static activities, both participant numbers and activity area were found to positively influence LAeq. The study also discovered that for both dynamic and static music activities, the lower the LAeq were when the people's formation approached a circular shape. This research offers valuable insights into understanding the acoustic environment and participant experience in urban open spaces.

How to get high-rise residential design to respond road traffic noise

Rapid urbanization causes acute contradictions of road traffic noise on residents' health. Although many works have been done in this field, specific investigations of how to get a design of residential area to correspond road traffic noise is still limited, especially in a high population dense area. This paper, therefore, focused on high-rise residential blocks, researching relations between design variables and distribution of road traffic noise. In the study, a typical high population dense city, Shenzhen was employed as study case. Based on noise map simulation, design element, block layout, design of individual buildings was proved important in traffic noise impact. The results discovered that the noise reduction effect is relatively significant when the building setback is within 30 - 40 meters of setback curb. To minimize traffic noise impact, flexible layout of board point perimeter type might play an important role. Lowering building heights with increasing the number of building rows, two-story podiums around high-rise buildings, and the addition of balcony railing plate could result in significant noise reductions. Focusing on design elements, this work developed an overall evaluation to improve acoustic environment of high-rise residentials based on noise map simulation, and provided significant contributions in responding road traffic noise.

Designing a practical physical framework for AI-enhanced sound detection and localization in vehicles

This paper presents the practical framework of an AI-implemented system currently in development for the detection and localization of external sound events to the vehicle. We delve into the initial block of the automotive project, analyzing sounds of interest and the noise we encounter, addressing the strategic arrangement of the four microphones on the sides of the vehicle, conceived as the sound input system. This configuration not only optimizes signal capture but also acts as sensitive ears, allowing the system to effectively analyze the acoustic environment. To mitigate wind interference, we have designed a microphone placement system that considers the vehicle's aerodynamics. The strategic location and implementation of aerodynamic protectors significantly minimize the impact of wind on the microphones, ensuring a sharper capture of acoustic signals. Complementing this arrangement, we apply advanced noise elimination processes, further enhancing the quality of the captured signals. Although in its early stages, this project aspires to provide effective solutions for vehicular acoustic perception, marking the beginning of a journey towards innovation in the detection and localization of sounds in mobile environments.

Navigating soundscape standardization: understanding barriers to the ISO 12913 implementation

This paper explores challenges and opportunities surrounding the implementation of the ISO 12913 series on soundscape, established by the International Organization for Standardization (ISO) to standardize definitions, frameworks, and methodologies for soundscape research. Through semi-structured interviews with National Standards Bodies (NSBs) representatives and focus group discussions with soundscape experts and stakeholders, the paper unveils barriers such as a lack of national interest, resource constraints, and insufficient awareness and literacy about soundscape theory. This study offers an opportunity to the broader field of environmental standards, giving practical insights for overcoming barriers and promoting the (further) adoption of ISO 12913 for healthier acoustic environments.

Noise in a UK intensive care unit: a retrospective cohort study

Excessive noise in hospital Intensive care units (ICU) has been associated with adverse health effects and human factor impacts acknowledged to negatively affect both patients and healthcare providers. Aims: Evaluation of the acoustic environment of the Royal Liverpool University Hospital (RLUH) ICU versus WHO and UK guidelines. Methods: Noise measurements were taken from a six-bedded bay within the RLUH ICU between 15th June and 1st July 2022. This audit focussed on noise data > 87dBA, in accordance with the national exposure limit established by UK Noise Regulations. A retrospective review of relevant patients' records was conducted to identify potential noisy events during the audit period. Results: The highest and lowest LAeq value was 77.9 and 63.5dBA, respectively. All LAeq and LAmax noise measurements recorded exceeded recommended guidelines. Noise fell below recommended daytime guidelines less than 1% of the time. The top potential causes of noise were patient repositioning/personal care, medication administration and suctioning. Conclusion: Noise levels in the RLUH ICU considerably exceed national and international guidelines. These findings highlight the need to address noise pollution in the ICU setting. Hospital staff and policy makers should consider implementing strategies and interventions for noise reduction in ICUs.

Implementation of an experimental set-up for insertion loss measurements of sonic crystal acoustic screens

The use of metamaterials for the implementation of noise control devices in the context of environmental acoustics is a topic that has gained more and more attention in recent years. The complex design of such devices and the difficulty of their construction in real-world applications complicates the acquisition of experimental data related to their acoustical performance. Numerical simulation tools are used to simulate the behaviour of these novel noise control devices in their design phase and help to validate the designs by comparing them with experimental data. This data, usually acquired under controlled conditions, holds significant importance in confirming the increasingly precise numerical models that have been developed over the years to simulate the behaviour of these physical systems. In this paper, an experimental set-up that enables acquisition of acoustical performance data for a particular metamaterial-based noise control device, consisting of networks of isolated scatterers, is presented. This prototype possesses several distinctive characteristics that render it particularly interesting, including its adaptability, ease of use, speed of obtaining results, and, particularly, its economic viability in relation to the tests that can be conducted in an anechoic chamber.