Special Issue "Modelling, Simulation and Data Analysis in Acoustical Problems"

A special issue of Applied Sciences (ISSN 2076-3417). This special issue belongs to the section "Acoustics and Vibrations".

Deadline for manuscript submissions: 31 December 2018

Special Issue Editors

Guest Editor
Prof. Dr. Claudio Guarnaccia

Civil Engineering Department, University of Salerno, 4084 Fisciano SA, Italy
Website | E-Mail
Interests: acoustics; environmental acoustics; room acoustics; field measurements; modelling and simulation; data analysis
Guest Editor
Prof. Dr. Lamberto Tronchin

Department of Architecture, University of Bologna, 40126 Bologna BO, Italy
Website 1 | Website 2 | E-Mail
Interests: energy performance; noise and vibration; 3D auralisation; buildings' exergy; architectural acoustics; musical acoustics
Guest Editor
Prof. Eng. Massimo Viscardi

Department of Industrial Engineering, University of Napoli, 80138 Napoli NA, Italy
Website | E-Mail
Interests: acoustic; vibration; aircraft/train/automotive noise emission and control; environmental and interior acoustics; experimental testing methods; computational vibroacoustic; passive noise control; active noise control

Special Issue Information

Dear Colleagues,

Modelling and simulation in acoustics problems are gathering more and more importance. In fact, with the development and improvement of innovative computational techniques, and with the growing need for predictive models, an impressive boost has been observed in this domain. The design of a model needs a proper conversion of reality to functions and parameters. On the other hand, once a model has been designed, an adequate simulation must be run, in terms of modelling and computational parameters. Keeping in mind the limitations and the approximations of any model, data analysis, both online and offline, is the last step of this process and can be extremely important to extract the required output from the process. This Special Issue is aimed at the collection of original research papers on theoretical and applicative studies on acoustics modelling, simulation, and data analysis. An interdisciplinary approach is encouraged. Research topics to be considered for a valid submission are all the issues related to the above description. Authors are invited to submit their work related to the following topics (but not limited to them):

  • Modelling and Simulation in Environmental Acoustics

  • Modelling and Simulation in Room Acoustics

  • Modelling and Simulation in Musical Acoustics

  • Online and offline data analysis

  • Predictive model implementation and validation

  • Residuals and Error evaluation and statistics

  • Signal analysis and parameters evaluation

  • etc.

Prof. Dr. Claudio Guarnaccia
Prof. Dr. Lamberto Tronchin
Prof. Eng. Massimo Viscardi
Guest Editors

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All papers will be peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Applied Sciences is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 1400 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • Acoustics

  • Vibration

  • Environmental acoustics

  • Room Acoustics

  • Modelling

  • Simulation

  • Data Analysis

  • Error evaluation and metrics

Published Papers (11 papers)

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Research

Open AccessArticle Spatial Information on Voice Generation from a Multi-Channel Electroglottograph
Appl. Sci. 2018, 8(9), 1560; https://doi.org/10.3390/app8091560
Received: 13 August 2018 / Revised: 31 August 2018 / Accepted: 3 September 2018 / Published: 5 September 2018
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Abstract
In the acoustics of human voice, an important role is reserved for the study of larynx movements. One of the most important aspects of the physical behavior of the larynx is the proper description and simulation of swallowing and singing register changes, which
[...] Read more.
In the acoustics of human voice, an important role is reserved for the study of larynx movements. One of the most important aspects of the physical behavior of the larynx is the proper description and simulation of swallowing and singing register changes, which require complex laryngeal manoeuvres. In order to describe (and solve, in some cases) these actions, it is fundamental to analyze the accurate synchronization of vocal fold adduction/abduction and the change of the larynx position. In the case of dysfunction, which often occurs for professional singers, this synchronization can be disturbed. The simultaneous assessment of glottal dynamics (typically electroglottograph, EGG signal) and larynx position might be useful for the diagnosis of disordered voice and swallowing. Currently, it is very difficult to instantaneously gather this information because of technology problems. In this work, we implemented a time-multiplex measurement approach of space-resolved transfer impedances through the larynx (Multi-Channel electroglottograph MC-EGG). For this purpose, we developed specific software (Labview code) for the visualization of the main waveforms in the study of the EGG signals. Moreover, the data acquired by the Labview code have been used to create a theoretical algorithm for deriving the position of the larynx inside the neck. Finally, we verified the results of the algorithm for the 3D larynx movement by comparing the data acquired with the values described in the literature. The paths of the larynx and the displacement on the sagittal and transverse plans matched the ones known for the emission of low/high notes and for swallowing. Besides, we have introduced the possibility to study the movement on the coronal (x) plan (so far, unexplored), which might be a starting point for further analysis. Full article
(This article belongs to the Special Issue Modelling, Simulation and Data Analysis in Acoustical Problems)
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Open AccessArticle Enhancing Target Speech Based on Nonlinear Soft Masking Using a Single Acoustic Vector Sensor
Appl. Sci. 2018, 8(9), 1436; https://doi.org/10.3390/app8091436
Received: 15 June 2018 / Revised: 24 July 2018 / Accepted: 25 July 2018 / Published: 23 August 2018
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Abstract
Enhancing speech captured by distant microphones is a challenging task. In this study, we investigate the multichannel signal properties of the single acoustic vector sensor (AVS) to obtain the inter-sensor data ratio (ISDR) model in the time-frequency (TF) domain. Then, the monotone functions
[...] Read more.
Enhancing speech captured by distant microphones is a challenging task. In this study, we investigate the multichannel signal properties of the single acoustic vector sensor (AVS) to obtain the inter-sensor data ratio (ISDR) model in the time-frequency (TF) domain. Then, the monotone functions describing the relationship between the ISDRs and the direction of arrival (DOA) of the target speaker are derived. For the target speech enhancement (SE) task, the DOA of the target speaker is given, and the ISDRs are calculated. Hence, the TF components dominated by the target speech are extracted with high probability using the established monotone functions, and then, a nonlinear soft mask of the target speech is generated. As a result, a masking-based speech enhancement method is developed, which is termed the AVS-SMASK method. Extensive experiments with simulated data and recorded data have been carried out to validate the effectiveness of our proposed AVS-SMASK method in terms of suppressing spatial speech interferences and reducing the adverse impact of the additive background noise while maintaining less speech distortion. Moreover, our AVS-SMASK method is computationally inexpensive, and the AVS is of a small physical size. These merits are favorable to many applications, such as robot auditory systems. Full article
(This article belongs to the Special Issue Modelling, Simulation and Data Analysis in Acoustical Problems)
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Open AccessArticle The Accuracy of Predicted Acoustical Parameters in Ancient Open-Air Theatres: A Case Study in Syracusae
Appl. Sci. 2018, 8(8), 1393; https://doi.org/10.3390/app8081393
Received: 20 June 2018 / Revised: 9 August 2018 / Accepted: 10 August 2018 / Published: 17 August 2018
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Abstract
Nowadays, ancient open-air theatres are often re-adapted as performance spaces for the additional historical value they can offer to the spectators’ experience. Therefore, there has been an increasing interest in the modelling and simulation of the acoustics of such spaces. These open-air performance
[...] Read more.
Nowadays, ancient open-air theatres are often re-adapted as performance spaces for the additional historical value they can offer to the spectators’ experience. Therefore, there has been an increasing interest in the modelling and simulation of the acoustics of such spaces. These open-air performance facilities pose several methodological challenges to researchers and practitioners when it comes to precisely measure and predict acoustical parameters. Therefore this work investigates the accuracy of predicted acoustical parameters, that is, the Reverberation Time (T20), Clarity (C80) and Sound Strength (G), taking the ancient Syracusae open-air theatre in Italy as a case study. These parameters were derived from both measured and simulated Impulse Responses (IR). The accuracy of the acoustic parameters predicted with two different types of acoustic software, due to the input variability of the absorption and scattering coefficients, was assessed. All simulated and measured parameters were in good agreement, within the range of one “just noticeable difference” (JND), for the tested coefficient combinations. Full article
(This article belongs to the Special Issue Modelling, Simulation and Data Analysis in Acoustical Problems)
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Open AccessArticle Acoustic Localization for a Moving Source Based on Cross Array Azimuth
Appl. Sci. 2018, 8(8), 1281; https://doi.org/10.3390/app8081281
Received: 5 June 2018 / Revised: 24 July 2018 / Accepted: 28 July 2018 / Published: 1 August 2018
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Abstract
Acoustic localization for a moving source plays a key role in engineering applications, such as wildlife conservation and health protection. Acoustic detection methods provide an alternative to traditional radar and infrared detection methods. Here, an acoustic locating method of array signal processing based
[...] Read more.
Acoustic localization for a moving source plays a key role in engineering applications, such as wildlife conservation and health protection. Acoustic detection methods provide an alternative to traditional radar and infrared detection methods. Here, an acoustic locating method of array signal processing based on intersecting azimuth lines of two arrays is introduced. The locating algorithm and the precision simulation of a single array shows that such a single array has good azimuth precision and bad range estimation. Once another array of the same type is added, the moving acoustic source can be located precisely by intersecting azimuth lines. A low-speed vehicle is used as the simulated moving source for the locating experiments. The length selection of short correlation and moving path compensation are studied in the experiments. All results show that the proposed novel method locates the moving sound source with high precision (<5%), while requiring fewer instruments than current methods. Full article
(This article belongs to the Special Issue Modelling, Simulation and Data Analysis in Acoustical Problems)
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Open AccessArticle Automatic Bowel Motility Evaluation Technique for Noncontact Sound Recordings
Appl. Sci. 2018, 8(6), 999; https://doi.org/10.3390/app8060999
Received: 9 May 2018 / Revised: 8 June 2018 / Accepted: 13 June 2018 / Published: 19 June 2018
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Abstract
Information on bowel motility can be obtained via magnetic resonance imaging (MRI)s and X-ray imaging. However, these approaches require expensive medical instruments and are unsuitable for frequent monitoring. Bowel sounds (BS) can be conveniently obtained using electronic stethoscopes and have recently been employed
[...] Read more.
Information on bowel motility can be obtained via magnetic resonance imaging (MRI)s and X-ray imaging. However, these approaches require expensive medical instruments and are unsuitable for frequent monitoring. Bowel sounds (BS) can be conveniently obtained using electronic stethoscopes and have recently been employed for the evaluation of bowel motility. More recently, our group proposed a novel method to evaluate bowel motility on the basis of BS acquired using a noncontact microphone. However, the method required manually detecting BS in the sound recordings, and manual segmentation is inconvenient and time consuming. To address this issue, herein, we propose a new method to automatically evaluate bowel motility for noncontact sound recordings. Using simulations for the sound recordings obtained from 20 human participants, we showed that the proposed method achieves an accuracy of approximately 90% in automatic bowel sound detection when acoustic feature power-normalized cepstral coefficients are used as inputs to artificial neural networks. Furthermore, we showed that bowel motility can be evaluated based on the three acoustic features in the time domain extracted by our method: BS per minute, signal-to-noise ratio, and sound-to-sound interval. The proposed method has the potential to contribute towards the development of noncontact evaluation methods for bowel motility. Full article
(This article belongs to the Special Issue Modelling, Simulation and Data Analysis in Acoustical Problems)
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Open AccessArticle A Multi-Frame PCA-Based Stereo Audio Coding Method
Appl. Sci. 2018, 8(6), 967; https://doi.org/10.3390/app8060967
Received: 18 April 2018 / Revised: 8 June 2018 / Accepted: 9 June 2018 / Published: 12 June 2018
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Abstract
With the increasing demand for high quality audio, stereo audio coding has become more and more important. In this paper, a multi-frame coding method based on Principal Component Analysis (PCA) is proposed for the compression of audio signals, including both mono and stereo
[...] Read more.
With the increasing demand for high quality audio, stereo audio coding has become more and more important. In this paper, a multi-frame coding method based on Principal Component Analysis (PCA) is proposed for the compression of audio signals, including both mono and stereo signals. The PCA-based method makes the input audio spectral coefficients into eigenvectors of covariance matrices and reduces coding bitrate by grouping such eigenvectors into fewer number of vectors. The multi-frame joint technique makes the PCA-based method more efficient and feasible. This paper also proposes a quantization method that utilizes Pyramid Vector Quantization (PVQ) to quantize the PCA matrices proposed in this paper with few bits. Parametric coding algorithms are also employed with PCA to ensure the high efficiency of the proposed audio codec. Subjective listening tests with Multiple Stimuli with Hidden Reference and Anchor (MUSHRA) have shown that the proposed PCA-based coding method is efficient at processing stereo audio. Full article
(This article belongs to the Special Issue Modelling, Simulation and Data Analysis in Acoustical Problems)
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Open AccessArticle Prediction of HIFU Propagation in a Dispersive Medium via Khokhlov–Zabolotskaya–Kuznetsov Model Combined with a Fractional Order Derivative
Appl. Sci. 2018, 8(4), 609; https://doi.org/10.3390/app8040609
Received: 17 March 2018 / Revised: 6 April 2018 / Accepted: 10 April 2018 / Published: 12 April 2018
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Abstract
High intensity focused ultrasound (HIFU) has been proven to be promising in non-invasive therapies, in which precise prediction of the focused ultrasound field is crucial for its accurate and safe application. Although the Khokhlov–Zabolotskaya–Kuznetsov (KZK) equation has been widely used in the calculation
[...] Read more.
High intensity focused ultrasound (HIFU) has been proven to be promising in non-invasive therapies, in which precise prediction of the focused ultrasound field is crucial for its accurate and safe application. Although the Khokhlov–Zabolotskaya–Kuznetsov (KZK) equation has been widely used in the calculation of the nonlinear acoustic field of HIFU, some deviations still exist when it comes to dispersive medium. This problem also exists as an obstacle to the Westervelt model and the Spherical Beam Equation. Considering that the KZK equation is the most prevalent model in HIFU applications due to its accurate and simple simulation algorithms, there is an urgent need to improve its performance in dispersive medium. In this work, a modified KZK (mKZK) equation derived from a fractional order derivative is proposed to calculate the nonlinear acoustic field in a dispersive medium. By correcting the power index in the attenuation term, this model is capable of providing improved prediction accuracy, especially in the axial position of the focal area. Simulation results using the obtained model were further compared with the experimental results from a gel phantom. Good agreements were found, indicating the applicability of the proposed model. The findings of this work will be helpful in making more accurate treatment plans for HIFU therapies, as well as facilitating the application of ultrasound in acoustic hyperthermia therapy. Full article
(This article belongs to the Special Issue Modelling, Simulation and Data Analysis in Acoustical Problems)
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Open AccessArticle Application of Elastic Wave Velocity for Estimation of Soil Depth
Appl. Sci. 2018, 8(4), 600; https://doi.org/10.3390/app8040600
Received: 21 March 2018 / Revised: 3 April 2018 / Accepted: 5 April 2018 / Published: 11 April 2018
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Abstract
Because soil depth is a crucial factor for predicting the stability at landslide and debris flow sites, various techniques have been developed to determine soil depth. The objective of this study is to suggest the graphical bilinear method to estimate soil depth through
[...] Read more.
Because soil depth is a crucial factor for predicting the stability at landslide and debris flow sites, various techniques have been developed to determine soil depth. The objective of this study is to suggest the graphical bilinear method to estimate soil depth through seismic wave velocity. Seismic wave velocity rapidly changes at the interface of two different layers due to the change in material type, packing type, and contact force of particles and thus, it is possible to pick the soil depth based on seismic wave velocity. An area, which is susceptible to debris flow, was selected, and an aerial survey was performed to obtain a topographic map and digital elevation model. In addition, a seismic survey and a dynamic cone penetration test were performed in this study. The comparison between the soil depth based on dynamic cone tests and the graphical bilinear method shows good agreement, indicating that the newly suggested soil depth estimating method may be usefully applied to predict soil depth. Full article
(This article belongs to the Special Issue Modelling, Simulation and Data Analysis in Acoustical Problems)
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Open AccessArticle A CFD Results-Based Approach to Investigating Acoustic Attenuation Performance and Pressure Loss of Car Perforated Tube Silencers
Appl. Sci. 2018, 8(4), 545; https://doi.org/10.3390/app8040545
Received: 1 March 2018 / Revised: 27 March 2018 / Accepted: 29 March 2018 / Published: 2 April 2018
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Abstract
This paper proposes an approach to investigating the effect of different temperatures and flow velocities on the acoustic performance of silencers in a more accurate and meticulous fashion, based on steady computational results of the flow field inside the silencer using computational fluid
[...] Read more.
This paper proposes an approach to investigating the effect of different temperatures and flow velocities on the acoustic performance of silencers in a more accurate and meticulous fashion, based on steady computational results of the flow field inside the silencer using computational fluid dynamics (CFD). This approach can transfer the CFD results—including temperature and flow velocity distribution—to acoustic meshes by mesh mapping. A numerical simulation on the sound field inside the silencer is then performed, using the CFD results as a boundary condition. This approach facilitates the analysis of complex silencer designs such as perforated tube silencers, and the numerical predictions are verified by a comparison with available experimental data. In the case of the three-pass perforated tube silencer of a car, the proposed approach is implemented to calculate the transmission loss (TL) of the silencer at different temperatures and flow velocities. We found that increasing the air temperature shifts the TL curve to a higher frequency and reduces the acoustic attenuation at most frequencies. As the air flow increases, the curve moves to a slightly lower frequency and the acoustic attenuation increases slightly. Additionally, the pressure loss of perforated tube silencers could be calculated according to the total pressure distribution of their inlet and outlet from the steady computational results using CFD. Full article
(This article belongs to the Special Issue Modelling, Simulation and Data Analysis in Acoustical Problems)
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Open AccessArticle A Pseudo-3D Model for Electromagnetic Acoustic Transducers (EMATs)
Appl. Sci. 2018, 8(3), 450; https://doi.org/10.3390/app8030450
Received: 31 January 2018 / Revised: 27 February 2018 / Accepted: 9 March 2018 / Published: 15 March 2018
Cited by 1 | PDF Full-text (6041 KB) | HTML Full-text | XML Full-text
Abstract
Previous methods for modelling Rayleigh waves produced by a meander-line-coil electromagnetic acoustic transducer (EMAT) consisted mostly of two-dimensional (2D) simulations that focussed on the vertical plane of the material. This paper presents a pseudo-three-dimensional (3D) model that extends the simulation space to both
[...] Read more.
Previous methods for modelling Rayleigh waves produced by a meander-line-coil electromagnetic acoustic transducer (EMAT) consisted mostly of two-dimensional (2D) simulations that focussed on the vertical plane of the material. This paper presents a pseudo-three-dimensional (3D) model that extends the simulation space to both vertical and horizontal planes. For the vertical plane, we combines analytical and finite-difference time-domain (FDTD) methods to model Rayleigh waves’ propagation within an aluminium plate and their scattering behaviours by cracks. For the horizontal surface plane, we employ an analytical method to investigate the radiation pattern of Rayleigh waves at various depths. The experimental results suggest that the models and the modelling techniques are valid. Full article
(This article belongs to the Special Issue Modelling, Simulation and Data Analysis in Acoustical Problems)
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Open AccessArticle Calculation of Noise Barrier Insertion Loss Based on Varied Vehicle Frequencies
Appl. Sci. 2018, 8(1), 100; https://doi.org/10.3390/app8010100
Received: 14 December 2017 / Revised: 2 January 2018 / Accepted: 5 January 2018 / Published: 11 January 2018
Cited by 1 | PDF Full-text (1875 KB) | HTML Full-text | XML Full-text
Abstract
A single frequency of 500 Hz is used as the equivalent frequency for traffic noise to calculate the approximate diffraction in current road barrier designs. However, the noise frequency changes according to the different types of vehicles moving at various speeds. The primary
[...] Read more.
A single frequency of 500 Hz is used as the equivalent frequency for traffic noise to calculate the approximate diffraction in current road barrier designs. However, the noise frequency changes according to the different types of vehicles moving at various speeds. The primary objective of this study is the development of a method of calculating the insertion loss based on frequencies. First, the noise emissions of a large number of vehicles classified by speed and type were measured to obtain data the noise spectrum. The corresponding relation between vehicle type, speed, and noise frequency was obtained. Next, the impact of different frequencies on the insertion loss was analyzed and was verified to be reasonable in experiments with different propagation distances compared to the analysis of a pure 500 Hz sound. In addition, calculations were applied in a case with different traffic flows, and the effect of a road noise barrier with different types of constituents and flow speeds were analyzed. The results show that sound pressure levels behind a barrier of a heavy vehicle flow or with a high speed are notably elevated. Full article
(This article belongs to the Special Issue Modelling, Simulation and Data Analysis in Acoustical Problems)
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