Applied Acoustics最新文献

{"title":"Characterization and warning criteria of metro rail corrugation based on vibration and noise data fusion","authors":"Yang Wang ,&nbsp;Hong Xiao ,&nbsp;Shaolei Wei ,&nbsp;Xiubo Liu ,&nbsp;Jiafu Cai ,&nbsp;Weize Zhao","doi":"10.1016/j.apacoust.2025.110686","DOIUrl":"10.1016/j.apacoust.2025.110686","url":null,"abstract":"<div><div>Online monitoring of track conditions using commercial trains is pivotal for advancing intelligent railway maintenance. This study introduces a novel Corrugation Vibration-Noise Index (CVNI) based on vibration-noise data fusion to detect rail corrugation via train body dynamic responses. The correlation between train body vibrations, carriage interior noise, and rail corrugation is systematically analyzed, and the CVNI calculation process is derived. The effects of measurement point location, train type, track structure, and curve radius on CVNI are thoroughly investigated. Additionally, an Energy Coupling Index (ECI) is introduced as an auxiliary indicator for rail corrugation detection. A rail corrugation warning criterion based on CVNI is established and validated using field data. The results indicate that, under the same rail corrugation excitation, vertical vibration acceleration signals of the train body are more sensitive to short-wavelength corrugation of 40–60 mm, while carriage interior noise signals are more sensitive to medium-to-long wavelength corrugation of 160 mm. CVNI balances the Vibration Index (VI) and Noise Index (NI), demonstrating robust generalization across varying curve radii and track structures. The combined use of CVNI and ECI effectively mitigates low-frequency noise interference during low-speed operations and accurately identifies rail corrugation sections. When compared to traditional testing methods, the error is reduced to just 1.27 %.</div></div>","PeriodicalId":55506,"journal":{"name":"Applied Acoustics","volume":"235 ","pages":"Article 110686"},"PeriodicalIF":3.4,"publicationDate":"2025-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143686847","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Speech intelligibility improvement for public address systems in noisy environments based on automatic gain selection in octave bands","authors":"Józef Kotus,&nbsp;Grzegorz Szwoch","doi":"10.1016/j.apacoust.2025.110683","DOIUrl":"10.1016/j.apacoust.2025.110683","url":null,"abstract":"<div><div>A method of speech intelligibility improvement in public address (PA) systems installed in reverberant acoustic spaces is proposed. The method is mainly intended for systems operating in high background noise levels. The algorithm is based on the near end listening enhancement approach. Signal-to-noise ratio (SNR) is evaluated in the octave frequency bands. Signal levels in the acoustic space are estimated using the measured impulse response of the room. Noise level is measured with the microphone, also a method of noise level estimation in presence of speech is proposed. Based on the calculated SNR values, a set of gain limits is selected, which allows for optimal utilization of the available acoustic power. Finally, gain values for the octave bands are calculated and applied to the speech signal. The overall performance of the proposed method was evaluated in a series of experiments performed in real acoustic spaces. Speech intelligibility was estimated using the STIPA index, measured with and without an additional, high-level noise source. The results indicate that the proposed method improved speech intelligibility in all tested cases, compared with the default PA system, especially in presence of a high-level background noise. The proposed method may be integrated with PA systems equipped with a digital signal processor.</div></div>","PeriodicalId":55506,"journal":{"name":"Applied Acoustics","volume":"235 ","pages":"Article 110683"},"PeriodicalIF":3.4,"publicationDate":"2025-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143686829","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Analysis and validation method for polarization phenomena based on acoustic vector Hydrophones","authors":"Zi Yang ,&nbsp;Erzheng Fang","doi":"10.1016/j.apacoust.2025.110669","DOIUrl":"10.1016/j.apacoust.2025.110669","url":null,"abstract":"<div><div>The concept of polarization originated in optics and has been extensively developed and applied in fields such as electromagnetism and seismicity. With the advent of vector sensors, this concept has been introduced into acoustics. However, research on acoustic polarization phenomena in underwater acoustics remains relatively scarce. Therefore, it is necessary to conduct an in-depth investigation into polarization phenomena in acoustic fields. This study proposes a method to analyze and verify the polarization phenomenon in underwater acoustic vector fields. Firstly, the article establishes the basic model of polarization phenomenon in an acoustic vector field, illustrates the time evolution of a bivariate signal in a three-dimensional representation, and elucidates the physical significance underlying this phenomenon. Subsequently, the polarization ellipse in the acoustic vector field and its characterization parameters are derived theoretically and estimated by simulation images. On this basis, the theory is extended to three-dimensional space, and a visual representation of signal polarization characteristics is achieved through the concept of polarization degree. Finally, the proposed method is validated by external field experiments and data analysis. The experimental results are consistent with the theoretical expectations, demonstrating the existence of polarization phenomena in the acoustic vector field.</div></div>","PeriodicalId":55506,"journal":{"name":"Applied Acoustics","volume":"235 ","pages":"Article 110669"},"PeriodicalIF":3.4,"publicationDate":"2025-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143643507","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Design and analysis of a microlattice structure for enhanced broadband sound absorption","authors":"Longhu Chen ,&nbsp;Chaoyan Wang ,&nbsp;Hongli Ji ,&nbsp;Jinhao Qiu","doi":"10.1016/j.apacoust.2025.110681","DOIUrl":"10.1016/j.apacoust.2025.110681","url":null,"abstract":"<div><div>This paper presents a novel microlattice structure designed for enhanced broadband sound absorption, leveraging the integration of a body-centered cubic (BCC) lattice with a triply periodic minimal surface (TPMS) I-Wrapped Package (IWP). The proposed microlattice sound absorber (MSA) features a hollow, two-stage parallel-coupled structure, which introduces multi-frequency dissipation components, achieving tunable and broadband sound absorption across a wide frequency range. The study employs both the LRF and JCA models to derive acoustic performance, and results are validated through numerical simulations and impedance tube experiments, demonstrating good agreement. Additionally, parametric analysis results demonstrate that increasing material thickness and reducing unit cell size can enhance overall sound absorption performance. Increasing the depth of the reserved back cavity can lower the peak frequency of the first-order sound absorption. The developed MSA structure is further applied in a muffler system, exhibiting broadband noise reduction and excellent ventilation performance. This research contributes a customizable and efficient approach to noise control, suitable for extreme environments, with broad applications in engineering fields such as aerospace and automotive industries.</div></div>","PeriodicalId":55506,"journal":{"name":"Applied Acoustics","volume":"235 ","pages":"Article 110681"},"PeriodicalIF":3.4,"publicationDate":"2025-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143686813","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Multifunctional hybrid metastructure with a combination of flower-shaped Helmholtz resonator and spiral labyrinth: Synergy enhancement in broadband sound absorption and high energy absorption performance","authors":"Weifan Kong ,&nbsp;Tao Fu ,&nbsp;Tao Liu ,&nbsp;Jinxiang Fang ,&nbsp;Sen Wang ,&nbsp;Chao Yang ,&nbsp;Miao Zhao","doi":"10.1016/j.apacoust.2025.110684","DOIUrl":"10.1016/j.apacoust.2025.110684","url":null,"abstract":"<div><div>The increase of the running speed of high-speed trains is accompanied by the continuous increase of the internal noise of the carriage, and the total noise reduction capacity of the sandwich structure, which is the main component of the carriage wall, is limited under the constraints of space dimension and size, which poses a new challenge to the acoustic performance design of the sandwich structure. Based on that, this paper proposes a novel compact composite structure, which consists of a flower-shaped Helmholtz resonator incorporating an embedded tube, a microperforated plate, and a spiral-shaped labyrinth sound-absorbing structure from top to bottom. Simulations of the structure were performed utilizing the finite element analysis software COMSOL, and the results were verified through standing wave tube sound absorption tests. A strong alignment was noted between the experimental outcomes and the simulation results. The results reveal that the average sound absorption coefficient of the structure surpasses 0.95 within the frequency band of 394 Hz to 548 Hz, achieving nearly perfect sound wave absorption. At the resonance frequency of 394 Hz, the peak absorption coefficient attains 0.981369, despite the structure’s thickness being only one-fifteenth of the wavelength corresponding to the absorption peak frequency, highlighting its distinctive deep-subwavelength properties. Even when the structure’s height is reduced to 60 mm, it maintains a wide sound absorption bandwidth, featuring a bandwidth ratio of 70 % where the sound absorption coefficient exceeds 0.5. The structure exemplifies deep-subwavelength properties by effectively managing large wavelengths despite its small size. Furthermore, the energy absorption characteristics of the composite structure are analyzed. It is found that the composite structure has excellent energy absorption characteristics and sound absorption performance. This study proposes a lightweight metastructure with exceptional acoustic performance, it has potential application value in the skin structure of high-speed trains and other transportation equipment.</div></div>","PeriodicalId":55506,"journal":{"name":"Applied Acoustics","volume":"235 ","pages":"Article 110684"},"PeriodicalIF":3.4,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143643511","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Experimental Investigations on the Interplay between a thermoacoustic oscillator and an external acoustic driver with different waveforms","authors":"Shancheng Tao ,&nbsp;Liu Liu ,&nbsp;Zhaoyu Li ,&nbsp;Lihua Tang ,&nbsp;Zhibin Yu ,&nbsp;Geng Chen","doi":"10.1016/j.apacoust.2025.110678","DOIUrl":"10.1016/j.apacoust.2025.110678","url":null,"abstract":"<div><div>Recent studies have reported on the various nonlinear behaviors (e.g., synchronization) resulting from the mutual interaction between a thermoacoustic oscillator and an external acoustic driver producing sinusoidal waves. This work extends previous research by experimentally investigating the dynamic behavior of a thermoacoustic oscillator subjected to external disturbances with different waveforms including triangular and irregular waves. The experimental data are analyzed using various signal processing techniques such as Fast Fourier Transform, wavelet transform, and phase space trajectories. Results reveal that apart from sinusoidal waves, both triangular and irregular waves can be utilized to synchronize the thermoacoustic oscillator. When synchronization occurs, the oscillator will transit from initial periodic oscillations at the natural frequency to final periodic oscillations at the driving frequency. The acoustic pressure resembles the external disturbance at the open end (e.g., triangular waves) but shifts towards sinusoidal waves when approaching the closed end. It is found that synchronization can happen if the dominant frequency of the external disturbance closely aligns with the natural frequency of the oscillator, even in the presence of harmonic components. This study provides an experimental framework for investigating the dynamic behavior of thermoacoustic oscillators under external disturbances, enhancing our understanding of synchronization phenomena in thermoacoustic devices.</div></div>","PeriodicalId":55506,"journal":{"name":"Applied Acoustics","volume":"235 ","pages":"Article 110678"},"PeriodicalIF":3.4,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143643509","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Bio-inspired underwater acoustic communication through PCHIP-based whistle generation and improved CSS modulation","authors":"Zhiwen Qiao ,&nbsp;Songzuo Liu ,&nbsp;Dexu Wang ,&nbsp;Yipeng Xing ,&nbsp;Tianyi Liu ,&nbsp;Jiaxuan Li","doi":"10.1016/j.apacoust.2025.110673","DOIUrl":"10.1016/j.apacoust.2025.110673","url":null,"abstract":"<div><div>Bio-inspired underwater acoustic communication has emerged as a promising approach for secure underwater communication by camouflaging signals as marine mammal vocalizations. However, conventional bio-inspired communication methods predominantly rely on fixed cetacean whistle patterns or limited whistle databases. The inherent predictability in signal frame structures significantly boosts their vulnerability to pattern recognition and adversarial detection. This consequently weakens the fundamental premise of bio-inspired communication systems, namely, their capacity to emulate natural marine mammal vocalizations for covert operations. To address this limitation, our research group proposed a novel bio-inspired secure communication model utilizing a piecewise cubic hermite interpolating polynomial (PCHIP) for simple whistle generation. The proposed approach ensured frequency continuity in signal design while maintaining high similarity to natural cetacean whistles. Subsequently, an improved chirp spread spectrum (CSS) modulation scheme was developed, and a PCHIP-based spread spectrum algorithm was introduced to generate random time-frequency spectral profiles. Particularly, randomly generated synchronization headers were incorporated with sliding correlation in the proposed system, enabling individual whistles to achieve both synchronization and information transmission capabilities. The integrated method significantly reinforced the covertness of bio-inspired communication while maintaining communication efficiency. The simulation results in shallow water environments demonstrated the effectiveness of our approach. Meanwhile, sea trials successfully achieved communication over 10 km distances with a bit error rate of <span><math><msup><mrow><mn>10</mn></mrow><mrow><mo>−</mo><mn>4</mn></mrow></msup></math></span>, validating the practical viability of the proposed system.</div></div>","PeriodicalId":55506,"journal":{"name":"Applied Acoustics","volume":"235 ","pages":"Article 110673"},"PeriodicalIF":3.4,"publicationDate":"2025-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143637595","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Efficient speech encryption algorithm based on three-dimensional quadratic exponential robust chaos","authors":"Yibo Huang ,&nbsp;Chong Li ,&nbsp;Zhiyong Li ,&nbsp;Qiuyu Zhang","doi":"10.1016/j.apacoust.2025.110672","DOIUrl":"10.1016/j.apacoust.2025.110672","url":null,"abstract":"<div><div>The computational accuracy and parameter spacing of the existing chaos result in the gradual degradation of the chaos, which makes the sequence become periodic sequence, and the divergence rate and divergence index of the existing chaos are low. In addition, the current speech encryption algorithm has high complexity and low computational efficiency. To solve these problems, a three-dimensional quadratic exponential chaos is proposed and an efficient speech encryption algorithm is designed. To solve the problem of slow numerical divergence, the double exponential nesting structure is used and the expansion factor <span><math><mi>b</mi><mi>e</mi><mi>t</mi><mi>a</mi></math></span> is introduced to effectively reduce the number of iterations when complete chaos is reached. In order to improve the internal complexity of chaotic sequence, the whole chaotic equation is standardized, so that the generated chaotic sequence has a wide distribution. Considering that the algorithm can be stably deployed in the hardware chip in the future, and take into account the encryption rate. In this paper, the speech encryption algorithm adopts the parallel processing of confusion and diffusion, and makes the residual processing of the generated encrypted speech to improve the scrambling effect and encryption efficiency. Simulation results show that the proposed chaos equation achieves remarkable exponential divergence rate, robustness and hardware deployability. The proposed speech encryption algorithm has high efficiency, low complexity, high noise ratio, can resist a series of attacks, and has high security. This paper presents an efficient encryption strategy for speech encryption.</div></div>","PeriodicalId":55506,"journal":{"name":"Applied Acoustics","volume":"235 ","pages":"Article 110672"},"PeriodicalIF":3.4,"publicationDate":"2025-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143637596","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Reflected sound field over microperforated panel systems","authors":"Raffaele Dragonetti ,&nbsp;Elio Di Giulio ,&nbsp;Annunziata Bruno ,&nbsp;Antonio Scofano ,&nbsp;Rosario Aniello Romano","doi":"10.1016/j.apacoust.2025.110628","DOIUrl":"10.1016/j.apacoust.2025.110628","url":null,"abstract":"<div><div>In this paper the reflected sound field over micro-perforated systems (MPPS) is investigated by using experimental, numerical and theoretical approaches. Two types of MPPS configurations are considered: one with an air cavity termination and the other with a honeycomb layer termination. A theoretical model to assess the reflected sound pressure and particles velocity fields by a microperforated panel backed by a honeycomb layer or by a simple air layer, as well as the angle of reflection, is reported. The theoretical method has been validated by means of experimental measurements in free field and numerical finite element simulations. Results highlight significant differences between MPPS in the case of honeycomb layer or when a simple air cavity is considered. Measurements performed in reverberation chamber and standing wave tube for the same micro-perforated panel have been carried out as well, allowing a further validation of the theoretical model. The latter measurements make possible, at the same time, experimentally appreciate the differences of the absorption coefficient values with and without honeycomb layer, in the case of normal, oblique and diffuse sound incidence.</div></div>","PeriodicalId":55506,"journal":{"name":"Applied Acoustics","volume":"235 ","pages":"Article 110628"},"PeriodicalIF":3.4,"publicationDate":"2025-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143620601","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Broadband sound reduction in space-coiling ventilation structures with microperforated shells","authors":"Yonghui Zhang,&nbsp;Lei Zhang,&nbsp;Youdong Duan,&nbsp;Xiaoming Zhou","doi":"10.1016/j.apacoust.2025.110676","DOIUrl":"10.1016/j.apacoust.2025.110676","url":null,"abstract":"<div><div>Ventilation structures supported by the Fano-like interference can act as high-performance sound silencers, yet the bandwidth gets limited eventually by coexisting resonant transmission. In this work, we focus on the space-coiling ventilation structure, and overcome the limitation by introducing a cylindrical shell made of microperforated panels (MPPs) in between the channel and ventilation pipe. The underlying mechanism is due to the resonance-induced field intensity enhancement within coiling channels, which can produce a significant pressure difference on both sides of the MPP to damp resonant acoustic transmission. Based on this behavior, broadband sound reduction with the bandwidth exceeding an octave can be achieved when two such structural elements are cascaded. Enhanced acoustic damping by MPPs and broadband sound reduction in bi-cell structures are numerically analyzed and validated experimentally.</div></div>","PeriodicalId":55506,"journal":{"name":"Applied Acoustics","volume":"235 ","pages":"Article 110676"},"PeriodicalIF":3.4,"publicationDate":"2025-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143620602","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}