Hasil untuk "Acoustics in engineering. Acoustical engineering"

Sasindran Shwetha, Devanand Nambukalithoppil, Srinivas Chelakkara Lakshmanan et al.

Accurate measurement of sound pressure level (SPL) is a cornerstone for understanding acoustic communication, animal behavior, and ecological dynamics. Acoustic signals can be broadly categorized into broadband and tonal sounds. Broadband noise – spanning a wide frequency range – is useful for assessing general noise levels, while tonal sounds, defined by distinct harmonic frequencies, provide critical insight into subtle phenomena such as animal communication, echolocation, and specific patterns of noise pollution. Smartphone-based SPL measurement has emerged as an accessible and cost-effective alternative to conventional sound level meters (SLMs). However, previous evaluations of SPL applications have primarily relied on iOS platforms and broadband noise measurements, leaving a significant gap in understanding how these tools perform for tonal sound measurements on Android devices – the more widely used operating system. To address these limitations, our study evaluated top three freely available Android SPL applications – Bolden, Kewlsoft, and KTW – against a Brüel & Kjær Class I SLM. The assessment employed both white noise and tonal stimuli across frequencies representative of natural soundscapes, facilitating a comprehensive performance comparison. Among these, the Bolden Sound Level Meter consistently delivered the most accurate readings for tonal measurements, whereas KTW performed well for broadband noise measurement, demonstrating the potential of Android-based tools in advancing environmental monitoring and wildlife conservation initiatives.

Redondo Martinez Patricia, King Eoin A.

It has been nearly three decades since the European Commission adopted the Green Paper on Future Noise Policy in 1996, marking a pivotal step towards developing an EU – wide noise policy, ultimately leading in 2002 to the formal adoption of Directive 2002/49/EC, known as the Environmental Noise Directive. The END mandates that the EU Member States develop strategic noise maps and action plans every five years. Since its inception, four rounds of noise mapping and action planning have been completed: the first in 2007, followed by subsequent rounds in 2012, 2017 and 2022. These efforts have systematically assessed environmental noise exposure across Europe, informing action plans aimed at reducing its impacts. A significant evolution in EU noise policy has been the requirement for all EU Member States to use Common Noise Assessment Methods in Europe for their noise mapping activities. Based on mapping results, road traffic continues to be the primary source of environmental noise in urban areas, with millions of individuals exposed to harmful noise levels. Increasing evidence underscores the health risks associated with noise exposure, with studies suggesting that reducing road traffic noise to levels recommended by the World Health Organization could lead to significant improvements in public health outcomes. Despite these concerns, obtaining accurate and comprehensive noise data from Member States remains a persistent challenge. This paper examines the data submitted from EU Member States under the END and identifies critical needs for the future.

Rindel Jens Holger, Petersen Claus Møller

Acoustic research and other activities at the Technical University of Denmark can be traced back to 1935, although it was not until 1966 that the university established an acoustical laboratory with new laboratory facilities of very high quality. The spark that initiated this development was the building of studios for the Danish Broadcasting 1931, that became an acoustical scandal and revealed the need for scientifically based knowledge on room acoustics and sound insulation. The rector of the Technical University, P.O. Pedersen, professor at the laboratory of tele-communication technique, started an acoustic research group in 1935, and he was the driving force in establishing a laboratory of sound technology in 1941. This was in the buildings of the Technical University, and some of the staff started to teach acoustics to the university students. P.O. Pedersen picked three young engineers for the acoustics research group: Vilhelm Jordan, Per Brüel, and Fritz Ingerslev. All three became of substantial importance for the development of acoustics in Denmark and worldwide; Jordan in concert hall acoustics, Brüel by establishing the B&K company, and Ingerslev as a professor at the university and a driving force in international cooperation (ICA, I-INCE) and standardization (ISO).

M. Scigliuzzo, L. Peyruchat, Riccardo Maria Marabini et al.

Precise control of mechanical modes in the quantum regime is a key resource for quantum technologies, offering promising pathways for quantum sensing with macroscopic systems and scalable architectures for quantum simulation. In this work, we realise a multimode mechanical cavity coupled to a superconducting Kerr resonator, which induces nonlinearity in the mechanical modes. The Kerr mode is realised by a flux-tunable SQUID array resonator, while the mechanical modes are implemented by a surface acoustic wave (SAW) cavity. Both mechanical and electromagnetic modes are individually addressable via dedicated measurement lines, enabling full spectroscopic characterisation. We introduce a straightforward protocol to measure the SQUID array resonator's participation ratio in the hybrid acoustic modes, quantifying the degree of hybridisation. The participation ratio reveals that our device operates at the onset of the multimode coupling regime, where multiple acoustic modes simultaneously interact with the nonlinear superconducting element. Furthermore, this platform allows controllable Kerr-type nonlinearities in multiple acoustic modes, with the participation ratio serving as the key parameter determining both the dissipation rates and nonlinear strengths of these hybridised modes. Close to the resonant regime, we measure a cross-Kerr interaction between seven pairs of mechanical modes, which is controllable via the SQUID array resonator detuning. These results establish a platform for engineering nonlinear multimode mechanical interactions, offering potential for future integration with superconducting qubits and implementation of multiple mechanical qubits.

Budnik Maximilian, Mees Valentin

This technical article presents a systematic methodology for efficient design, modeling, and validation of an Active Noise Control (ANC) system under free field conditions, aiming for global noise reduction. The presented three-dimensional (3D) Finite Element (FE) based simulation approach enables efficient ANC system design by generating valid data. It further allows for the optimization of control algorithms, evaluation of the attenuation performance, and methodical iteration of the overall concept design. A mock-up of a mobile ventilation system equipped with an ANC array serves as a demonstrator to present the stages of this methodology and its practicality. Starting with general concept considerations, the numerical modeling procedure, the different stages of verification and validation and concluding with an optimization task to achieve global noise reduction. The physical model of the demonstrator has been experimentally validated, and the efficiency of the developed ANC system confirmed through standardized sound power measurements in a semi-anechoic chamber. The findings reinforce the elaborated simulation process and demonstrate the real-world applicability of ANC systems. They also prove the potential for using simulations to develop free field 3D ANC systems capable of achieving global noise reduction.

Corcuera-Marruffo Andrea, Meyer-Kahlen Nils, Lokki Tapio

The directivity of sound sources plays an important role in the generation of auralizations. Researchers have invested a considerable amount of time and effort in generating directivity databases of musical instruments with high levels of detail. However, it is still unclear how precisely these data should be captured and modeled with respect to perception. Therefore, investigating if simplified patterns with lower spatial resolutions are perceptibly different from higher-resolution patterns provides valuable insights into determining the spatial resolution required for perceptually significant measurement and modeling of directivity patterns. In this study, we present a listening test that investigates the spatial resolution of the magnitude of directivity patterns using different spherical harmonic orders of two musical instruments (a trumpet and a flute) in two listener positions and rooms. Apart from changing the resolution for the entire simulation, we also tested hybrid responses for one of the rooms, where the order was modified only for the direct sound or the early reflections.

Zhao Huanqi, Chen Kean, Li Hao et al.

Acoustic comfort is an important factor that passengers and crew usually consider for their on-board wellness. The classification is an efficient way to show the level of acoustic comfort on board. Most of the existing classification approaches of on-board noise in different spaces are based on the decibel based indicators which describes the loudness. However, acoustic comfort is not only relevant to decibel based indicators but also perceptual attributes such as timbre and pitch. In order to provide more perceptual support, a satisfaction based classification method for acoustic comfort is modified, determining the limits of the noise in different task-oriented spaces on board. Perceptual assessments were carried out to obtain numerical values for acoustic comfort as noise comfort index (NCI) and measured satisfaction (SM) of each noise sample. Analysis made on these two descriptors indicated that the NCI has a strong relationship with SM. Therefore, satisfaction can be regarded as a basic perceptual guideline to classify the acoustic comfort and determine the limits of each level for each task-oriented space. A linear acoustic comfort model was established to predict the NCI based on the acoustic parameters. Comparison with the previous classification of on-board noise showed that there is a mismatch between the NCI and sound pressure level (SPL), and NCI can not be fully represented by SPL.

Lu Huanran, Xing Guangzhen, Yang Ping et al.

High-frequency focused ultrasonic technology offers distinct advantages in microstructural inspection and high-resolution imaging owing to its short wavelength and superior acoustic field-focusing capability. Accurate determination of focused acoustic field characteristics is essential for reliable defect evaluation and image quality. This study proposes a precise method for calibrating the effective radius of high-frequency focusing ultrasonic transducer and −6 dB beamwidth of its acoustic field – two key parameters that directly affect the spatial resolution and focusing accuracy. A theoretical acoustic field model was established based on the Rayleigh integral, and the computational efficiency was enhanced using the Fresnel approximation. A hydrophone-based experiment was designed: the iterative method was employed to invert the geometric focal length and effective radius by analyzing the extrema (maximum and minimum values) of the on-axis acoustic pressure distribution, while the −6 dB beamwidth was determined by incorporating a spatial averaging correction into the analysis of the focal plane pressure profile. The experimental results demonstrate that the determined beamwidths agree with the measured values to within 3% across a frequency range of up to 100 MHz, thereby confirming the accuracy, robustness and practical applicability of the proposed calibration approach.

Shraddha Surana, Ashwin Srinivasan, Michael Bain

Engineering information systems for scientific data analysis presents significant challenges: complex workflows requiring exploration of large solution spaces, close collaboration with domain specialists, and the need for maintainable, interpretable implementations. Traditional manual development is time-consuming, while "No Code" approaches using large language models (LLMs) often produce unreliable systems. We present iProg, a tool implementing Interactive Structured Inductive Programming. iProg employs a variant of a '2-way Intelligibility' communication protocol to constrain collaborative system construction by a human and an LLM. Specifically, given a natural-language description of the overall data analysis task, iProg uses an LLM to first identify an appropriate decomposition of the problem into a declarative representation, expressed as a Data Flow Diagram (DFD). In a second phase, iProg then uses an LLM to generate code for each DFD process. In both stages, human feedback, mediated through the constructs provided by the communication protocol, is used to verify LLMs' outputs. We evaluate iProg extensively on two published scientific collaborations (astrophysics and biochemistry), demonstrating that it is possible to identify appropriate system decompositions and construct end-to-end information systems with better performance, higher code quality, and order-of-magnitude faster development compared to Low Code/No Code alternatives. The tool is available at: https://shraddhasurana.github.io/dhaani/

Shalini Chakraborty, Sebastian Baltes

The IT industry provides supportive pathways such as returnship programs, coding boot camps, and buddy systems for women re-entering their job after a career break. Academia, however, offers limited opportunities to motivate women to return. We propose a diverse multicultural research project investigating the challenges faced by women with software engineering (SE) backgrounds re-entering academia or related research roles after a career break. Career disruptions due to pregnancy, immigration status, or lack of flexible work options can significantly impact women's career progress, creating barriers for returning as lecturers, professors, or senior researchers. Although many companies promote gender diversity policies, such measures are less prominent and often under-recognized within academic institutions. Our goal is to explore the specific challenges women encounter when re-entering academic roles compared to industry roles; to understand the institutional perspective, including a comparative analysis of existing policies and opportunities in different countries for women to return to the field; and finally, to provide recommendations that support transparent hiring practices. The research project will be carried out in multiple universities and in multiple countries to capture the diverse challenges and policies that vary by location.

Mia Mohammad Imran, Tarannum Shaila Zaman

Large Language Models (LLMs) are increasingly used in empirical software engineering (ESE) to automate or assist annotation tasks such as labeling commits, issues, and qualitative artifacts. Yet the reliability and reproducibility of such annotations remain underexplored. Existing studies often lack standardized measures for reliability, calibration, and drift, and frequently omit essential configuration details. We argue that LLM-based annotation should be treated as a measurement process rather than a purely automated activity. In this position paper, we outline the \textbf{Operationalization for LLM-based Annotation Framework (OLAF)}, a conceptual framework that organizes key constructs: \textit{reliability, calibration, drift, consensus, aggregation}, and \textit{transparency}. The paper aims to motivate methodological discussion and future empirical work toward more transparent and reproducible LLM-based annotation in software engineering research.

Mengxi Wu, Zhiteng Ma, Zhenhua Tian et al.

Advanced biofabrication techniques can create tissue-like constructs that can be applied for reconstructive surgery or as in vitro three-dimensional (3D) models for disease modeling and drug screening. While various biofabrication techniques have recently been widely reviewed in the literature, acoustics-based technologies still need to be explored. The rapidly increasing number of publications in the past two decades exploring the application of acoustic technologies highlights the tremendous potential of these technologies. In this review, we contend that acoustics-based methods can address many limitations inherent in other biofabrication techniques due to their unique advantages: noncontact manipulation, biocompatibility, deep tissue penetrability, versatility, precision in-scaffold control, high-throughput capabilities, and the ability to assemble multilayered structures. We discuss the mechanisms by which acoustics directly dictate cell assembly across various biostructures and examine how the advent of novel acoustic technologies, along with their integration with traditional methods, offers innovative solutions for enhancing the functionality of organoids. Acoustic technologies are poised to address fundamental challenges in biofabrication and tissue engineering and show promise for advancing the field in the coming years.

Joseph Rufo, Peiran Zhang, Ruoyu Zhong et al.

Newly developed acoustic technologies are playing a transformational role in life science and biomedical applications ranging from the activation and inactivation of mechanosensitive ion channels for fundamental physiological processes to the development of contact-free, precise biofabrication protocols for tissue engineering and large-scale manufacturing of organoids. Here, we provide our perspective on the development of future acoustic technologies and their promise in addressing critical challenges in biomedicine. Acoustic techniques are moving towards the clinic. Here the authors highlight recent developments in the areas of acoustic mechanobiology, point-of-care diagnostics, in vivo manipulation and tissues engineering, and provide their thoughts on the current challenges and directions for future work.

Ambrosio Leonardo A., Gouesbet Gérard

The description of acoustical waves can be achieved using an expansion over basic functions with weighting coefficients which may be called beam shape coefficients (BSCs). There is a strong analogy between the scalar formalism of acoustical waves and the vectorial electromagnetic formalism, known as generalized Lorenz–Mie theory (GLMT), describing the interaction between a homogeneous sphere and an arbitrary illuminating beam. In particular, BSCs have been introduced as well in GLMT and the mathematical arsenal to evaluate them, developed since several decades, can be used mutatis mutandis to evaluate BSCs in acoustics. In particular, the present paper introduces a method named localized approximation to the evaluation of the acoustical BSCs, similar to the localized approximation used to evaluate electromagnetic BSCs, in the case of Bessel beams. Such a formalism akin to the electromagnetic GLMT may be viewed as an acoustical GLMT and should allow a renewal of the calculation of various properties of acoustical wave scattering, in particular to the design of acoustical tweezers similar to optical tweezers.

Wang Qiaochu, Hongwei Wang, He Xiaoyu et al.

People exhibit a range of negative reactions to noise. However, previous study on masking secondary radiation noise focused on its impact on a single negative reaction, namely dissatisfaction. This is a gap in understanding the mechanisms that mitigate multi-dimensional negative reactions (MNR), which encompass various emotional responses to noise, including annoyance, dissatisfaction, and others. Therefore, this study selected four mutually independent critical reactions (subjective loudness, depression, discomfort, and dissatisfaction) and analyzed the masking effects of adding four types of water sounds (fountain, stream, water-drop, and waterfall sounds) on MNR caused by secondary radiation noise. Seventy-nine participants were presented with a series of combined sound samples before casting their votes of MNR in an auditory test booth. The results revealed that adding the four types of water sounds mitigated the MNR induced by secondary radiation noise. Among them, the water-drop sound was the most effective, while the waterfall sound was the least capable. The fountain sound was preferred over the stream sound for optimizing the MNR, focusing on subjective loudness, discomfort and dissatisfaction, which were caused by higher level of combined sound. Furthermore, as global A-weighted sound level (LAeq) increased from 55 to 65 dBA, the mean subjective loudness levels generally remained the highest. Beyond the subjective loudness, when global LAeq increased to 65 dBA, the mean depression level exceeded the mean discomfort level and mean dissatisfaction level when the fountain or water-drop sound was added, whereas the three mean levels remained approximately equal when the stream or waterfall sound was added.

Mohamed Mimoun, Fréour Vincent, Vergez Christophe et al.

Based on a physical model of a trumpet’s functioning, the numerical continuation approach is used to construct the model’s bifurcation diagram, which depends on the instrument’s acoustic characteristics and the musician’s parameters. In this article, we first identify 10 descriptors that account for the main characteristics of each bifurcation diagram. It is first shown that these descriptors can be used to classify four professional trumpets with a recognition rate close to 100%. The XGBoost algorithm is used for this purpose. Secondly, we evaluate the ability of different classical machine learning algorithms to predict the values of the 10 descriptors given the acoustic characteristics of a trumpet and the value of the musician’s parameters. The best surrogate model is obtained using the LassoLars method, trained on a dataset of 12,000 bifurcation diagrams calculated by numerical continuation. Training takes just 2 min, and real-time predictions are accurate, with an error of approximately 1%. A software interface has been developed to enable trumpet designers to predict the values of the descriptors for a trumpet being designed, without any knowledge of physics or nonlinear dynamics.

Nikhil Patnaik, Joseph Hallett, Awais Rashid

Writing secure code is challenging and so it is expected that, following the release of code-generative AI tools, such as ChatGPT and GitHub Copilot, developers will use these tools to perform security tasks and use security APIs. However, is the code generated by ChatGPT secure? How would the everyday software or security engineer be able to tell? As we approach the next decade we expect a greater adoption of code-generative AI tools and to see developers use them to write secure code. In preparation for this, we need to ensure security-by-design. In this paper, we look back in time to Saltzer & Schroeder's security design principles as they will need to evolve and adapt to the challenges that come with a world of AI-generated code.

Vimal Manohar, Szu-Jui Chen, Zhiqi Wang et al.

This paper summarizes our acoustic modeling efforts in the Johns Hopkins University speech recognition system for the CHiME-5 challenge to recognize highly-overlapped dinner party speech recorded by multiple microphone arrays. We explore data augmentation approaches, neural network architectures, front-end speech dereverberation, beamforming and robust i-vector extraction with comparisons of our in-house implementations and publicly available tools. We finally achieved a word error rate of 69.4% on the development set, which is a 11.7% absolute improvement over the previous baseline of 81.1%, and release this improved baseline with refined techniques/tools as an advanced CHiME-5 recipe.

Claudio Di Sipio, Riccardo Rubei, Juri Di Rocco et al.

Software engineering (SE) activities have been revolutionized by the advent of pre-trained models (PTMs), defined as large machine learning (ML) models that can be fine-tuned to perform specific SE tasks. However, users with limited expertise may need help to select the appropriate model for their current task. To tackle the issue, the Hugging Face (HF) platform simplifies the use of PTMs by collecting, storing, and curating several models. Nevertheless, the platform currently lacks a comprehensive categorization of PTMs designed specifically for SE, i.e., the existing tags are more suited to generic ML categories. This paper introduces an approach to address this gap by enabling the automatic classification of PTMs for SE tasks. First, we utilize a public dump of HF to extract PTMs information, including model documentation and associated tags. Then, we employ a semi-automated method to identify SE tasks and their corresponding PTMs from existing literature. The approach involves creating an initial mapping between HF tags and specific SE tasks, using a similarity-based strategy to identify PTMs with relevant tags. The evaluation shows that model cards are informative enough to classify PTMs considering the pipeline tag. Moreover, we provide a mapping between SE tasks and stored PTMs by relying on model names.

Yi Sun, Chihua Lu, Zhien Liu et al.