Pub Date : 2023-05-09DOI: 10.3390/acoustics5020028
Cristian Albero, Beatriz Sánchez-Tabuenca
In this paper, an experimental methodology to characterize the noise paths in a washing machine with a horizontal axis was developed. The noise paths considered in this research were the noise that escapes through holes, the non-resonant path through the panels, and the noise radiated by the panels of the cabinet. The characterization method was based on several sound intensity measurements on the outside panels of the washing machine. In addition to these measurements, characterization of the radiation factor was performed by applying a method that relates intensity and vibration measurements while the structure of the washing machine is excited using a shaker. Applying the methodology to a washing machine, the main transmission path of the noise along the frequency domain where this home appliance has its highest values was identified. This methodology can provide the manufacturer with a guide to improve the acoustic performance of washing machines by applying noise control solutions in the noise path depending on the frequency domain.
{"title":"Experimental Methodology to Characterize the Noise Paths in a Horizontal-Axis Washing Machine","authors":"Cristian Albero, Beatriz Sánchez-Tabuenca","doi":"10.3390/acoustics5020028","DOIUrl":"https://doi.org/10.3390/acoustics5020028","url":null,"abstract":"In this paper, an experimental methodology to characterize the noise paths in a washing machine with a horizontal axis was developed. The noise paths considered in this research were the noise that escapes through holes, the non-resonant path through the panels, and the noise radiated by the panels of the cabinet. The characterization method was based on several sound intensity measurements on the outside panels of the washing machine. In addition to these measurements, characterization of the radiation factor was performed by applying a method that relates intensity and vibration measurements while the structure of the washing machine is excited using a shaker. Applying the methodology to a washing machine, the main transmission path of the noise along the frequency domain where this home appliance has its highest values was identified. This methodology can provide the manufacturer with a guide to improve the acoustic performance of washing machines by applying noise control solutions in the noise path depending on the frequency domain.","PeriodicalId":72045,"journal":{"name":"Acoustics (Basel, Switzerland)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43068748","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-05-05DOI: 10.3390/acoustics5020027
Ante Skoblar, Goranka Štimac Rončević, D. Lanc, Sanjin Braut
In this paper, the dynamic response of a Euler–Bernoulli beam subjected to transverse harmonic forces is calculated. The method of separation of variables combined with the mode shape superposition method, which includes the determination of eigenvalues, is used to define the velocity field of the beam surface. The Rayleigh integral was used to calculate the sound radiation and the beam was placed in an infinite baffle. Additional actuators are introduced in order to minimize the sound radiation, or, more specifically, the total sound power level of the vibrating beam, and their optimal position and force amplitude are determined; the conclusions were drawn from the optimization results. This paper proposes a method for faster determination of the optimal actuator parameters in order to achieve the minimum total sound power level. The validity of the obtained results is demonstrated with examples, whose solutions are compared to the results in the published literature.
{"title":"Acoustic Radiation of a Beam Subjected to Transverse Load","authors":"Ante Skoblar, Goranka Štimac Rončević, D. Lanc, Sanjin Braut","doi":"10.3390/acoustics5020027","DOIUrl":"https://doi.org/10.3390/acoustics5020027","url":null,"abstract":"In this paper, the dynamic response of a Euler–Bernoulli beam subjected to transverse harmonic forces is calculated. The method of separation of variables combined with the mode shape superposition method, which includes the determination of eigenvalues, is used to define the velocity field of the beam surface. The Rayleigh integral was used to calculate the sound radiation and the beam was placed in an infinite baffle. Additional actuators are introduced in order to minimize the sound radiation, or, more specifically, the total sound power level of the vibrating beam, and their optimal position and force amplitude are determined; the conclusions were drawn from the optimization results. This paper proposes a method for faster determination of the optimal actuator parameters in order to achieve the minimum total sound power level. The validity of the obtained results is demonstrated with examples, whose solutions are compared to the results in the published literature.","PeriodicalId":72045,"journal":{"name":"Acoustics (Basel, Switzerland)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49331204","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-04-28DOI: 10.3390/acoustics5020025
E. Cárdenas, Samuel K. Takazawa, M. Garcés, D. Chichester, R. Hunley, Chris Young
Persistent low-frequency (<180 Hz) acoustic detection took place within the boundaries of Oak Ridge National Laboratory to monitor full power operations of the High Flux Isotope Reactor. Three acoustic sensors were installed at distances of 69, 101, and 914 m from the northeast corner of the cooling towers to monitor and assess four reactor power generation cycles. Features were extracted from power spectral density calculations where data were collected during reactor on and off operations. Diverse spectral features were present during full reactor power, including a 21.4 Hz fundamental frequency and ascending harmonics. Using bandpass filters, these related frequencies were isolated and summed, and the root mean square energy was calculated. The method of isolating and summing characteristic features provided a significant improvement in identifying acoustic behavior related to reactor power when the raw signals were obscured by noise.
{"title":"An Assessment of Persistent Acoustic Monitoring of a Nuclear Reactor during Full Power Generation","authors":"E. Cárdenas, Samuel K. Takazawa, M. Garcés, D. Chichester, R. Hunley, Chris Young","doi":"10.3390/acoustics5020025","DOIUrl":"https://doi.org/10.3390/acoustics5020025","url":null,"abstract":"Persistent low-frequency (<180 Hz) acoustic detection took place within the boundaries of Oak Ridge National Laboratory to monitor full power operations of the High Flux Isotope Reactor. Three acoustic sensors were installed at distances of 69, 101, and 914 m from the northeast corner of the cooling towers to monitor and assess four reactor power generation cycles. Features were extracted from power spectral density calculations where data were collected during reactor on and off operations. Diverse spectral features were present during full reactor power, including a 21.4 Hz fundamental frequency and ascending harmonics. Using bandpass filters, these related frequencies were isolated and summed, and the root mean square energy was calculated. The method of isolating and summing characteristic features provided a significant improvement in identifying acoustic behavior related to reactor power when the raw signals were obscured by noise.","PeriodicalId":72045,"journal":{"name":"Acoustics (Basel, Switzerland)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47084852","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-04-28DOI: 10.3390/acoustics5020026
R. Burnham, D. Duffus
Organisms use multi-modal, scale-dependent, sensory information to decipher their surroundings. This can include, for example, recognizing the presence of con- or heterospecifics, including a predatory threat, the presence and abundance of prey, or navigational cues to travel between breeding or feeding areas. Here we advocate for the use of the concept of active space to understand the extent to which an individual might be sending and receiving habitat information, describing this as the active component of their niche space. We present the use of active space as a means to understand ecological interactions, giving focus to those species whose active space is acoustically defined, in particular, cetacean species. We show how the application of estimates of active space, and changes in extent, can help better understand the potential disturbance effects of changes in the soundscape, and be a useful metric to estimate possible adverse effects even when stress responses, or behavioral or calling modifications are not obvious.
{"title":"Implication of Altered Acoustic Active Space for Cetacean Species That Result from Soundscape Changes and Noise Additions","authors":"R. Burnham, D. Duffus","doi":"10.3390/acoustics5020026","DOIUrl":"https://doi.org/10.3390/acoustics5020026","url":null,"abstract":"Organisms use multi-modal, scale-dependent, sensory information to decipher their surroundings. This can include, for example, recognizing the presence of con- or heterospecifics, including a predatory threat, the presence and abundance of prey, or navigational cues to travel between breeding or feeding areas. Here we advocate for the use of the concept of active space to understand the extent to which an individual might be sending and receiving habitat information, describing this as the active component of their niche space. We present the use of active space as a means to understand ecological interactions, giving focus to those species whose active space is acoustically defined, in particular, cetacean species. We show how the application of estimates of active space, and changes in extent, can help better understand the potential disturbance effects of changes in the soundscape, and be a useful metric to estimate possible adverse effects even when stress responses, or behavioral or calling modifications are not obvious.","PeriodicalId":72045,"journal":{"name":"Acoustics (Basel, Switzerland)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43477706","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-04-19DOI: 10.3390/acoustics5020024
Dapeng Wei, Bilong Liu, Ludi Kang
The control of decentralized velocity feedback on curved aircraft plates under turbulent boundary layer excitations is numerically investigated in this paper. Sixteen active control units are set on the plate to reduce the vibration and sound radiation of the plate. The computational results from the two methods are compared to verify the accuracy of the numerical model. The plate kinetic energy and the radiated sound power under turbulent boundary layer and control unit excitations are analyzed. The influences of control unit distribution, plate thickness and curvature on radiated sound are discussed. Unlike a flat plate, the control of the lower-order high radiation modes of a curved plate under TBL excitations is critical since these modes predominate the sound radiations. The control of these modes, however, is sensitive to the ratio of the stiffness associated with the membrane tensions to the stiffness associated with the bending forces. This ratio implies that the plate curvature and the thickness play an important role in the control effect. When the plate is thinner and the radius is smaller, the control is less effective.
{"title":"Numerical Investigation of Distributed Speed Feedback Control of Turbulent Boundary Layer Excitation Curved Plates Radiation Noise","authors":"Dapeng Wei, Bilong Liu, Ludi Kang","doi":"10.3390/acoustics5020024","DOIUrl":"https://doi.org/10.3390/acoustics5020024","url":null,"abstract":"The control of decentralized velocity feedback on curved aircraft plates under turbulent boundary layer excitations is numerically investigated in this paper. Sixteen active control units are set on the plate to reduce the vibration and sound radiation of the plate. The computational results from the two methods are compared to verify the accuracy of the numerical model. The plate kinetic energy and the radiated sound power under turbulent boundary layer and control unit excitations are analyzed. The influences of control unit distribution, plate thickness and curvature on radiated sound are discussed. Unlike a flat plate, the control of the lower-order high radiation modes of a curved plate under TBL excitations is critical since these modes predominate the sound radiations. The control of these modes, however, is sensitive to the ratio of the stiffness associated with the membrane tensions to the stiffness associated with the bending forces. This ratio implies that the plate curvature and the thickness play an important role in the control effect. When the plate is thinner and the radius is smaller, the control is less effective.","PeriodicalId":72045,"journal":{"name":"Acoustics (Basel, Switzerland)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47730957","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-04-12DOI: 10.3390/acoustics5020023
F. Martellotta, S. Liuzzi, Chiara Rubino
Rupestrian churches are spaces obtained from excavation of soft rocks that are frequently found in many Mediterranean countries. In the present paper the church dedicated to Saints Andrew and Procopius, located close to the city of Monopoli in Apulia (Italy) is studied. On-site acoustical measures were made, obtaining a detailed description of the acoustics in the current state pointing out, thanks to a combination of analysis techniques, the presence of significant modal behavior in the low frequencies, causing reverberation time to be about 2 s, four times longer than in the other bands, as well as being strongly dependent on source and receiver position (with variations of about 1 s when source is moved outside the chancel). However, as the church is characterized by significant degradation of surfaces and large amounts of debris cover the floor, the original acoustic conditions can be expected to somewhat differ. Acoustical modelling can be very helpful in grasping the original conditions, but given the small dimensions of the space, conventional geometrical acoustic prediction methods cannot be applied to simulate the low-frequency behavior. Thus, the present paper proposes an application of finite-difference-time-domain (FDTD) computation to simulate the low-frequency behavior and analyze a possible reconstruction of the original state. Results showed that a very good agreement was obtained between predictions and measurements, both in terms of resonance frequencies and reverberation times that differed by less than 5%. Modal response strongly affected the acoustical conditions also in the hypothetical reconstruction of the original state, although the sound field proved to be more uniform than in the current state.
{"title":"Reviving the Low-Frequency Response of a Rupestrian Church by Means of FDTD Simulation","authors":"F. Martellotta, S. Liuzzi, Chiara Rubino","doi":"10.3390/acoustics5020023","DOIUrl":"https://doi.org/10.3390/acoustics5020023","url":null,"abstract":"Rupestrian churches are spaces obtained from excavation of soft rocks that are frequently found in many Mediterranean countries. In the present paper the church dedicated to Saints Andrew and Procopius, located close to the city of Monopoli in Apulia (Italy) is studied. On-site acoustical measures were made, obtaining a detailed description of the acoustics in the current state pointing out, thanks to a combination of analysis techniques, the presence of significant modal behavior in the low frequencies, causing reverberation time to be about 2 s, four times longer than in the other bands, as well as being strongly dependent on source and receiver position (with variations of about 1 s when source is moved outside the chancel). However, as the church is characterized by significant degradation of surfaces and large amounts of debris cover the floor, the original acoustic conditions can be expected to somewhat differ. Acoustical modelling can be very helpful in grasping the original conditions, but given the small dimensions of the space, conventional geometrical acoustic prediction methods cannot be applied to simulate the low-frequency behavior. Thus, the present paper proposes an application of finite-difference-time-domain (FDTD) computation to simulate the low-frequency behavior and analyze a possible reconstruction of the original state. Results showed that a very good agreement was obtained between predictions and measurements, both in terms of resonance frequencies and reverberation times that differed by less than 5%. Modal response strongly affected the acoustical conditions also in the hypothetical reconstruction of the original state, although the sound field proved to be more uniform than in the current state.","PeriodicalId":72045,"journal":{"name":"Acoustics (Basel, Switzerland)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42934919","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-04-04DOI: 10.3390/acoustics5020022
Albert Prinn
Accurate predictions of the wave-dominated region of an acoustic field in a room can be generated using wave-based computational methods. One such method is the finite element method (FEM). With presently available computing power and advanced numerical techniques, it is possible to obtain FEM predictions of sound fields in rooms with complicated geometries and complex boundary conditions in realistic time frames. The FEM has been continuously developed since its inception and attempts to provide solutions in real time using finite element-based methods are beginning to appear in the literature; these developments are especially interesting for auralization and virtual acoustics applications. To support these efforts, and provide a resource for neophytes, the use of the FEM for room acoustics is reviewed in this article. A history is presented alongside examples of the method’s derivation, implementation, and solutions. The current challenges and state-of-the-art are also presented, and it is found that the most recent contributions to the field make use of one or a mixture of the following: the finite element-based discontinuous Galerkin method, extended reaction boundary conditions written in the frequency domain but solved in the time domain, and the solution of large-scale models using parallel processing and graphics processing units.
{"title":"A Review of Finite Element Methods for Room Acoustics","authors":"Albert Prinn","doi":"10.3390/acoustics5020022","DOIUrl":"https://doi.org/10.3390/acoustics5020022","url":null,"abstract":"Accurate predictions of the wave-dominated region of an acoustic field in a room can be generated using wave-based computational methods. One such method is the finite element method (FEM). With presently available computing power and advanced numerical techniques, it is possible to obtain FEM predictions of sound fields in rooms with complicated geometries and complex boundary conditions in realistic time frames. The FEM has been continuously developed since its inception and attempts to provide solutions in real time using finite element-based methods are beginning to appear in the literature; these developments are especially interesting for auralization and virtual acoustics applications. To support these efforts, and provide a resource for neophytes, the use of the FEM for room acoustics is reviewed in this article. A history is presented alongside examples of the method’s derivation, implementation, and solutions. The current challenges and state-of-the-art are also presented, and it is found that the most recent contributions to the field make use of one or a mixture of the following: the finite element-based discontinuous Galerkin method, extended reaction boundary conditions written in the frequency domain but solved in the time domain, and the solution of large-scale models using parallel processing and graphics processing units.","PeriodicalId":72045,"journal":{"name":"Acoustics (Basel, Switzerland)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43236581","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-03-26DOI: 10.3390/acoustics5020021
Francisco Fernández-Zacarías, Juan Luis Beira-Jiménez, Virginia Puyana-Romero, Ricardo Hernández-Molina
The study aims to diagnose the sound pressure levels inside incubators in a controlled environment under free-field conditions. The tests were carried out in a semi-anechoic room under the standard UNE-EN ISO 3745:2012/A1:2018 in three different operating states: off, on, and on with a temperature alarm triggered. Sound pressure levels were analyzed in three different models of incubators, both inside and outside. The main noise indices analyzed were the corrected equivalent continuous level (LKeq) and the equivalent continuous level (Leq) in third-octave bands. The results obtained under normal operating conditions showed variations among the different incubators, with overall values between 48.8 and 56.3 dBA. The influence of the alarm considerably worsened these data. The values obtained showed that premature newborns are exposed to noise levels above international recommendations. All incubators tested showed the presence of tonal components, both outside and inside the incubator cabin, and, in some cases, low-frequency components, but no impulsivity components were observed in any case.
该研究旨在诊断在自由场条件下受控环境下孵化器内的声压级。测试在半消声室内进行，符合UNE-EN ISO 3745:2012/A1:2018标准，在三种不同的工作状态下进行:关闭、打开和打开，并触发温度警报。分析了三种不同型号恒温箱内、外的声压级。分析的主要噪声指标是校正后的等效连续电平(LKeq)和三倍频程的等效连续电平(Leq)。在正常操作条件下获得的结果显示，不同的培养箱之间存在差异，总体值在48.8到56.3 dBA之间。警报的影响大大恶化了这些数据。所获得的数值表明，早产新生儿接触到的噪音水平高于国际建议水平。所有测试的孵化器都显示出音调成分的存在，在孵化器舱室内外，在某些情况下，低频成分，但在任何情况下都没有观察到冲动性成分。
{"title":"Diagnosis of Noise Inside Neonatal Incubators under Free-Field Conditions","authors":"Francisco Fernández-Zacarías, Juan Luis Beira-Jiménez, Virginia Puyana-Romero, Ricardo Hernández-Molina","doi":"10.3390/acoustics5020021","DOIUrl":"https://doi.org/10.3390/acoustics5020021","url":null,"abstract":"The study aims to diagnose the sound pressure levels inside incubators in a controlled environment under free-field conditions. The tests were carried out in a semi-anechoic room under the standard UNE-EN ISO 3745:2012/A1:2018 in three different operating states: off, on, and on with a temperature alarm triggered. Sound pressure levels were analyzed in three different models of incubators, both inside and outside. The main noise indices analyzed were the corrected equivalent continuous level (LKeq) and the equivalent continuous level (Leq) in third-octave bands. The results obtained under normal operating conditions showed variations among the different incubators, with overall values between 48.8 and 56.3 dBA. The influence of the alarm considerably worsened these data. The values obtained showed that premature newborns are exposed to noise levels above international recommendations. All incubators tested showed the presence of tonal components, both outside and inside the incubator cabin, and, in some cases, low-frequency components, but no impulsivity components were observed in any case.","PeriodicalId":72045,"journal":{"name":"Acoustics (Basel, Switzerland)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46418919","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-03-16DOI: 10.3390/acoustics5010020
Shashidhar Rudregowda, Sudarshan Patil Kulkarni, Gururaj H L, Vinayakumar Ravi, M. Krichen
Visual speech recognition (VSR) is a method of reading speech by noticing the lip actions of the narrators. Visual speech significantly depends on the visual features derived from the image sequences. Visual speech recognition is a stimulating process that poses various challenging tasks to human machine-based procedures. VSR methods clarify the tasks by using machine learning. Visual speech helps people who are hearing impaired, laryngeal patients, and are in a noisy environment. In this research, authors developed our dataset for the Kannada Language. The dataset contained five words, which are Avanu, Bagge, Bari, Guruthu, Helida, and these words are randomly chosen. The average duration of each video is 1 s to 1.2 s. The machine learning method is used for feature extraction and classification. Here, authors applied VGG16 Convolution Neural Network for our custom dataset, and relu activation function is used to get an accuracy of 91.90% and the recommended system confirms the effectiveness of the system. The proposed output is compared with HCNN, ResNet-LSTM, Bi-LSTM, and GLCM-ANN, and evidenced the effectiveness of the recommended system.
{"title":"Visual Speech Recognition for Kannada Language Using VGG16 Convolutional Neural Network","authors":"Shashidhar Rudregowda, Sudarshan Patil Kulkarni, Gururaj H L, Vinayakumar Ravi, M. Krichen","doi":"10.3390/acoustics5010020","DOIUrl":"https://doi.org/10.3390/acoustics5010020","url":null,"abstract":"Visual speech recognition (VSR) is a method of reading speech by noticing the lip actions of the narrators. Visual speech significantly depends on the visual features derived from the image sequences. Visual speech recognition is a stimulating process that poses various challenging tasks to human machine-based procedures. VSR methods clarify the tasks by using machine learning. Visual speech helps people who are hearing impaired, laryngeal patients, and are in a noisy environment. In this research, authors developed our dataset for the Kannada Language. The dataset contained five words, which are Avanu, Bagge, Bari, Guruthu, Helida, and these words are randomly chosen. The average duration of each video is 1 s to 1.2 s. The machine learning method is used for feature extraction and classification. Here, authors applied VGG16 Convolution Neural Network for our custom dataset, and relu activation function is used to get an accuracy of 91.90% and the recommended system confirms the effectiveness of the system. The proposed output is compared with HCNN, ResNet-LSTM, Bi-LSTM, and GLCM-ANN, and evidenced the effectiveness of the recommended system.","PeriodicalId":72045,"journal":{"name":"Acoustics (Basel, Switzerland)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42523493","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-03-14DOI: 10.3390/acoustics5010019
H. Autio, N. Vardaxis, Delphine Bard Hagberg
Ray tracing is a frequently used method for acoustic simulations, valued for its calculation speed and ease of use. Although it is fast, there are no fully ray tracing-based real-time simulation methods or engines. Under real-time restrictions, ray tracing simulations lose precision and the variance inherent in the random simulation method has too much impact on the outcome. In this paper, an algorithm called iterative ray tracing is presented that reduces the negative effects of real-time restrictions by iteratively improving the initial calculation and increasing the precision over time. In addition, new estimates of the expected value and variance of ray tracing simulations are presented and used to show the iteration steps in the new algorithm reduce variance, while maintaining the expected value. Simulations using iterative ray tracing are compared to measurements and simulations using the classical ray tracing method, and it is shown that iterative ray tracing can be used to improve precision over time. Although more testing is needed, iterative ray tracing can be used to extend most ray tracing algorithms, in order to decrease the adverse effects of real-time restrictions.
{"title":"An Iterative Ray Tracing Algorithm to Increase Simulation Speed While Maintaining Overall Precision","authors":"H. Autio, N. Vardaxis, Delphine Bard Hagberg","doi":"10.3390/acoustics5010019","DOIUrl":"https://doi.org/10.3390/acoustics5010019","url":null,"abstract":"Ray tracing is a frequently used method for acoustic simulations, valued for its calculation speed and ease of use. Although it is fast, there are no fully ray tracing-based real-time simulation methods or engines. Under real-time restrictions, ray tracing simulations lose precision and the variance inherent in the random simulation method has too much impact on the outcome. In this paper, an algorithm called iterative ray tracing is presented that reduces the negative effects of real-time restrictions by iteratively improving the initial calculation and increasing the precision over time. In addition, new estimates of the expected value and variance of ray tracing simulations are presented and used to show the iteration steps in the new algorithm reduce variance, while maintaining the expected value. Simulations using iterative ray tracing are compared to measurements and simulations using the classical ray tracing method, and it is shown that iterative ray tracing can be used to improve precision over time. Although more testing is needed, iterative ray tracing can be used to extend most ray tracing algorithms, in order to decrease the adverse effects of real-time restrictions.","PeriodicalId":72045,"journal":{"name":"Acoustics (Basel, Switzerland)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44359272","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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