{"title":"On the indirect measurement of airflow resistivity of thin specimens in mid-frequencies via measured transfer matrix (T12).","authors":"S Pandey, D P Jena","doi":"10.1121/10.0039103","DOIUrl":"https://doi.org/10.1121/10.0039103","url":null,"abstract":"<p><p>Recent experiments demonstrated that airflow resistivity (AFR) of fibrous porous materials can be calculated indirectly via impedance and transmission loss tubes in the mid-frequency region [Pandey and Jena (2025). Meas. Sci. Technol. 36, 035901]. In the present work, a method for estimating AFR is devised using the second element, T12, of the four-pole parameters or the transfer matrix (T), of the given porous material, as measured via a transmission loss tube. The theoretical background is discussed first, followed by the finite element simulation [conducted according to ASTM (2019a) E2611-19 standard] on fourteen materials, sourced from literature, with AFR ranging from ∼ 2 to 99 kPa·s/m2. It is observed that these results depend significantly on the sample thickness, and by keeping the thickness in the range of 10-15 mm, the AFR can be estimated in a broadband mid-frequency region with errors of ≤ 2.6%. At last, experiments are conducted on five materials, three (fibrous materials, high AFR) having samples of three different thicknesses and the other two (low AFR) having thicknesses of 10 mm and 15 mm. The results are presented to authenticate the observations made from simulations, followed by the uncertainty analyses to determine the reliability.</p>","PeriodicalId":17168,"journal":{"name":"Journal of the Acoustical Society of America","volume":"158 4","pages":"2664-2675"},"PeriodicalIF":2.3,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145206595","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}
Vladimir E Ostashev, Michael B Muhlestein, D Keith Wilson, Sergey N Vecherin, Michelle L Eggleston, Matthew J Kamrath, Kent L Gee
{"title":"Angle-of-arrival fluctuations in a turbulent atmosphere.","authors":"Vladimir E Ostashev, Michael B Muhlestein, D Keith Wilson, Sergey N Vecherin, Michelle L Eggleston, Matthew J Kamrath, Kent L Gee","doi":"10.1121/10.0039516","DOIUrl":"https://doi.org/10.1121/10.0039516","url":null,"abstract":"<p><p>Atmospheric turbulence causes fluctuations in the angle-of-arrival (AOA) of sound waves. These fluctuations adversely affect the performance of sensor arrays used for source detection, ranging, and recognition. This article examines, from a theoretical perspective, the variance of the AOA fluctuations measured with two microphones. The AOA variance is expressed in terms of the propagation range, transverse distance between two microphones, acoustic frequency, and effective spectrum of quasi-homogeneous and isotropic turbulence, with parameters dependent upon the height above the ground. The effective spectrum is modeled with the von Kármán and Kolmogorov spectral models. In the latter case, the results simplify significantly, and the variance depends on the path-averaged effective structure-function parameter, which characterizes the intensity of temperature and wind velocity fluctuations in the inertial subrange of turbulence. The standard deviation of the AOA fluctuations is studied numerically for typical meteorological regimes of the daytime atmospheric boundary layer. For the cases considered, the standard deviation varies from a fraction of degree to around 1°-2°, and increases with increasing friction velocity and surface heat flux.</p>","PeriodicalId":17168,"journal":{"name":"Journal of the Acoustical Society of America","volume":"158 4","pages":"2714-2722"},"PeriodicalIF":2.3,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145251545","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":"Channel estimation under short pilot length in deep-sea underwater acoustic communications.","authors":"Yizhen Jia, Yik-Chung Wu, Zhongtao Chen, Bingyang Cheng, Wei Ge, Xiao Han, Jingwei Yin","doi":"10.1121/10.0039546","DOIUrl":"https://doi.org/10.1121/10.0039546","url":null,"abstract":"<p><p>Deep-sea underwater acoustic (UWA) channels typically exhibit pronounced sparsity and long delay spreads, with the sparsity pattern highly dependent on the locations of the transmitter and receiver. These characteristics bring significant challenges for channel estimator design. As a result, most existing methods require long pilot sequences to achieve accurate channel estimation. However, the use of lengthy pilots introduces considerable communication overhead and latency, which is not desirable in practice. To overcome this challenge, we propose a flexible, sparsity-aware channel estimation algorithm based on a generalized inverse Gaussian (GIG) prior. This approach eliminates the need of heavy parameter tuning, effectively accommodates diverse sparsity levels, and fully exploits the inherent sparsity of UWA channels. Consequently, the required pilot length can be reduced to approximately the channel length, while still ensuring accurate channel recovery and noise variance estimation. Simulation results demonstrate that the proposed GIG prior-based algorithm maintains high accuracy across a wide range of sparsity patterns, even when the pilot length is comparable to the channel length. Furthermore, experiments using real-world data from the South China Sea show that the proposed algorithm consistently achieves lower bit error rate than other state-of-the-art channel estimators, regardless of the equalizers used.</p>","PeriodicalId":17168,"journal":{"name":"Journal of the Acoustical Society of America","volume":"158 4","pages":"2813-2828"},"PeriodicalIF":2.3,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145274952","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}
Sebastian Hakansson, Philipp Schulze, Ralf Burgmayer, Erik W Schneehagen, Thomas F Geyer
{"title":"Numerical investigation of the noise generation of electric motors in urban air mobility vehiclesa).","authors":"Sebastian Hakansson, Philipp Schulze, Ralf Burgmayer, Erik W Schneehagen, Thomas F Geyer","doi":"10.1121/10.0039427","DOIUrl":"https://doi.org/10.1121/10.0039427","url":null,"abstract":"<p><p>Current concepts of urban air mobility vehicles usually rely on a set of individual electrically driven propulsion systems. Although aerodynamically generated noise from the rotors or fans remains the main contribution to the overall noise, noise generated by electric machines may well add to the total noise. This is especially true for fast-spinning electric motors that cause high-frequency noise contributions, which may notably increase the total noise and lead to unwanted psychoacoustic effects. In the current paper, the noise generation of two versions of permanent magnet synchronous machines in a conventional inrunner configuration, intended for use in a concept vehicle propelled by eight tiltable rotors, is investigated through numerical simulations and analytical models. One version is a direct drive, designed to deliver the torque and rotational speed required for the rotor directly. The other is a geared version, delivering a higher rotational speed and lower torque, thus requiring an additional gear box to drive the rotor. The results show that the geared motor version leads to notable noise contributions at frequencies of 2 kHz and 9 kHz. Coupled with a high radiation efficiency in this frequency range, the findings imply that noise from electric machines contributes to the total noise from the vehicle.</p>","PeriodicalId":17168,"journal":{"name":"Journal of the Acoustical Society of America","volume":"158 4","pages":"2647-2658"},"PeriodicalIF":2.3,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145199939","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":"Development and validation of a procedure to test perception of speech prosody in listeners with cochlear implants.","authors":"Harley J Wheeler, Matthew B Winn","doi":"10.1121/10.0039570","DOIUrl":"https://doi.org/10.1121/10.0039570","url":null,"abstract":"<p><p>Understanding vocal prosody is essential to successful communication. However, evaluations of speech recognition have relied heavily on word repetition-type tasks where success does not hinge on prosody perception, or where stimuli do not have enough prosodic variation to even test for this ability. Individuals who use cochlear implants (CIs) are at risk for poorer perception of prosody because of their limited access to pitch perception. This study used a multi-slider visual analog interface to measure perception of contrastive focus prosody in sentence-length stimuli by participants with CIs or with typical hearing (TH). Compared to TH listeners, CI users were more likely to misidentify which word had prosodic focus, as well as having weaker perception of prosodic focus, on average. Whereas TH listeners scaled their perceived strength of prosodic focus based on F0 and vowel intensity features, CI users scaled ratings in accordance with vowel intensity and vowel duration, with no relationship to F0. These results suggest that CI users are at risk of complete misperception of a talker's intended message, even in instances where there was no uncertainty about the words that were spoken.</p>","PeriodicalId":17168,"journal":{"name":"Journal of the Acoustical Society of America","volume":"158 4","pages":"2916-2930"},"PeriodicalIF":2.3,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145292555","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":"Bayesian-driven cyclic-cross-spectral matrix completion: Non-synchronous measurements for cyclostationary acoustic sourcesa).","authors":"Chenyu Zhang, Youhong Xiao, Yi Kuang, Qiannan Xu, Jianyuan He, Liang Yu","doi":"10.1121/10.0039554","DOIUrl":"https://doi.org/10.1121/10.0039554","url":null,"abstract":"<p><p>Accurate identification of cyclostationary acoustic sources, such as those generated by rotating machinery, is critical for noise control and fault diagnosis. Non-synchronous measurement (NSM) techniques using microphone arrays offer a cost-effective solution to overcome hardware limitations like insufficient aperture and spatial aliasing. However, existing methods, particularly fast iterative shrinkage-thresholding algorithm (FISTA)-based matrix completion algorithms, face two major challenges: (1) cumbersome parameter tuning due to reliance on empirical regularization and (2) lack of theoretical validation for cyclostationary scenarios where the low-rankness of cyclic-cross-spectral matrices (CCSMs) remains unproven. To address these issues, this paper proposes a Bayesian matrix completion framework tailored for cyclostationary NSM. The low-rank property of CCSM is rigorously established under cyclostationary conditions, and spatial continuity constraints are derived from frequency-shifted Green's function bases. A hierarchical Bayesian model is developed to automate parameter inference, eliminating manual tuning while integrating physical constraints. Numerical simulations demonstrate superior performance over FISTA, with lower matrix completion errors and source reconstruction errors under low signal-to-noise ratios and high-frequency regimes. Experimental validations, including loudspeaker localization and high-pressure pump noise mapping, confirm the method's ability to suppress aliasing artifacts, narrow main-lobewidth, and enhance spatial resolution.</p>","PeriodicalId":17168,"journal":{"name":"Journal of the Acoustical Society of America","volume":"158 4","pages":"2963-2978"},"PeriodicalIF":2.3,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145301525","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":"Adjoint-based optimization of open-loop control for microfluidics of an inkjet printhead.","authors":"Javier Lorente-Macías, Matthew P Juniper","doi":"10.1121/10.0039526","DOIUrl":"https://doi.org/10.1121/10.0039526","url":null,"abstract":"<p><p>We find the optimal actuator velocity profile that cancels acoustic reverberations inside drop-on-demand inkjet printheads and ensures a certain meniscus state at a specific time after ejection. We formulate an optimization problem to minimize the total energy of the three-dimensional oscillating flow in the microchannel at a given time. The total energy comprises the acoustic energy inside the microchannel and the surface energy of the droplet. We use an adjoint method to compute efficiently the gradient of the cost function with respect to the control boundary and a gradient-based optimization algorithm to converge to the optimal solution. We apply this methodology to two generic inkjet printhead mechanisms: one that forces the faces adjacent to the nozzle face and the other that forces the face opposite the nozzle face. In both cases, the actuator first reduces the surface energy of the system by extracting fluid from the nozzle. This causes acoustic waves to propagate through the channel and reflect off the junction with the manifolds, increasing the acoustic energy of the system. The actuator then sends additional acoustic waves that cancel these reverberations. Both mechanisms reduce the total energy of the system by a factor of over 100 compared with uncontrolled cases.</p>","PeriodicalId":17168,"journal":{"name":"Journal of the Acoustical Society of America","volume":"158 4","pages":"3280-3303"},"PeriodicalIF":2.3,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145345982","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}
Tao Zhuang, Mengtong Li, Shaozhe Li, Jia-Xin Zhong, Jing Lu
{"title":"Wideband sound reproduction using a massive multi-channel focusing parametric array loudspeaker system.","authors":"Tao Zhuang, Mengtong Li, Shaozhe Li, Jia-Xin Zhong, Jing Lu","doi":"10.1121/10.0039639","DOIUrl":"https://doi.org/10.1121/10.0039639","url":null,"abstract":"<p><p>Generating high-contrast, wideband audio in a confined target area remains challenging for conventional electrodynamic loudspeaker (EDL) arrays due to their large size and complex multi-channel processing. We present a 576-channel focusing parametric array loudspeaker (PAL) with compact 24 × 24 cm dimensions that modulates ultrasonic signals rather than wideband audio, enabling focused beam control with reduced hardware and processing demands. This work represents the first demonstration of wideband reproduction using a massive multi-channel focusing PAL, achieved through field-programmable gate array-based ultrasonic delay control combined with single-digital-to-analog converter modulation. Experimental results validate the approach, showing effective focal sound reproduction. This work presents a compact-size approach for high-contrast, wideband sound field control, which offers a potential alternative to conventional EDL arrays.</p>","PeriodicalId":17168,"journal":{"name":"Journal of the Acoustical Society of America","volume":"158 4","pages":"3339-3347"},"PeriodicalIF":2.3,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145346039","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":"Striation-based beamforming for a ship of opportunity in shallow water.","authors":"Donghyeon Kim, Gihoon Byun, Sungho Cho, H C Song","doi":"10.1121/10.0039521","DOIUrl":"https://doi.org/10.1121/10.0039521","url":null,"abstract":"<p><p>Coherent multipath arrivals in oceanic waveguides generate complex interference patterns that degrade the performance of conventional beamforming (CBF) on horizontal arrays, often causing azimuthal bias and sidelobes-especially in the endfire direction. These limitations stem from grazing-angle multipath propagation in the vertical plane. As a physics-based alternative, this study proposes striation-based beamforming (SBF), which leverages the waveguide invariant. SBF consists of three steps: (1) estimating the time-domain Green's function of an unknown broadband source via ray-based blind deconvolution, (2) resampling this Green's function along striation slopes (relative frequency shifts) aligned to the first arrival, and (3) applying CBF to the resampled Green's function. Anchoring to the first arrival-corresponding to the minimum grazing angle-allows SBF to reduce azimuthal bias and sidelobes. This study also introduces a simplified variant, termed CB1, which applies CBF exclusively to the first arrival, bypassing the resampling step. CB1 offers substantial computational savings while achieving performance comparable to SBF. Experimental results using a bottom-mounted horizontal array confirm CB1's effectiveness in tracking the azimuth of a ship of opportunity in shallow water.</p>","PeriodicalId":17168,"journal":{"name":"Journal of the Acoustical Society of America","volume":"158 4","pages":"2694-2702"},"PeriodicalIF":2.3,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145239002","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":"Analytical modelling and simulations of acoustic interaction with avian egg.","authors":"Zhao Li, Angela G Webb, Dominique A Potvin","doi":"10.1121/10.0039636","DOIUrl":"https://doi.org/10.1121/10.0039636","url":null,"abstract":"<p><p>Sound reception inside avian eggs is crucial for embryonic development and hatching synchrony, yet, conventional techniques are unable to directly measure the complex transmission of sound within the egg. To address this, an analytical model is developed to predict the interaction between acoustic waves and avian eggs, providing comprehensive insights into the acoustic characteristics inside the eggshell. The model approximates the egg as a layered spherical system, consisting of an eggshell, albumen, and yolk, with the potential inclusion of an embedded sensor or embryonic structure. Governing equations for elastic and viscous media are formulated, and continuity conditions for displacement and stress are enforced at each interface. Comprehensive parametric simulations are conducted to examine the effects of geometric and mechanical properties on resonance frequencies and internal pressure amplification. The results demonstrate that the eggshell radius predominantly governs the acoustic response, whereas variations in shell thickness and material properties have secondary effects. Frequency-dependent pressure gains in the albumen and yolk reveal significant amplification near resonance. Additionally, the impact of sensor insertion is assessed to determine optimal dimensions for minimising measurement distortion.</p>","PeriodicalId":17168,"journal":{"name":"Journal of the Acoustical Society of America","volume":"158 4","pages":"3083-3096"},"PeriodicalIF":2.3,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145308483","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}