Sabine, Eyring and Millington formulas are commonly used for reverberation time prediction, mainly, as a calculation tool in building acoustics design. These classical theories are valid only for rooms with diffuse sound fields, in which the energy density is constant throughout the enclosure, an acoustic condition that is achieved only when using surfaces with low sound absorption. Despite these limitations, Sabine’s formula is still the most widely used in the prediction of the reverberation time, when spaces such as classrooms or offices are addressed. However, for these rooms, after the construction works are completed, it is quite often verified that the implemented sound-absorbent surface area is manifestly insufficient to fulfill the reverberation time requirement. In this technical note a simplified approach for reverberation time prediction, based on the use of Sabine’s formula, is proposed, that can be useful in acoustic design of classrooms or offices, due to its simplicity. A previous correction to the sound absorption coefficient of the lining materials declared by the manufacturer is here proposed, making use of an empirical correction that was achieved from in situ experimental results and through geometrical room acoustic modelling. The empirical correction can be employed for room conditions where diffuse sound field is not met, composed of small or medium volumes (volume below 300 m3), with regular geometry, approaching parallelepipedal shapes, where the average height is below 4.0 m.
{"title":"Proposal of a simplified methodology for reverberation time prediction in standard medium size rooms with non-uniformly distributed sound absorption","authors":"D. Mateus, A. Pereira","doi":"10.1051/aacus/2023025","DOIUrl":"https://doi.org/10.1051/aacus/2023025","url":null,"abstract":"Sabine, Eyring and Millington formulas are commonly used for reverberation time prediction, mainly, as a calculation tool in building acoustics design. These classical theories are valid only for rooms with diffuse sound fields, in which the energy density is constant throughout the enclosure, an acoustic condition that is achieved only when using surfaces with low sound absorption. Despite these limitations, Sabine’s formula is still the most widely used in the prediction of the reverberation time, when spaces such as classrooms or offices are addressed. However, for these rooms, after the construction works are completed, it is quite often verified that the implemented sound-absorbent surface area is manifestly insufficient to fulfill the reverberation time requirement. In this technical note a simplified approach for reverberation time prediction, based on the use of Sabine’s formula, is proposed, that can be useful in acoustic design of classrooms or offices, due to its simplicity. A previous correction to the sound absorption coefficient of the lining materials declared by the manufacturer is here proposed, making use of an empirical correction that was achieved from in situ experimental results and through geometrical room acoustic modelling. The empirical correction can be employed for room conditions where diffuse sound field is not met, composed of small or medium volumes (volume below 300 m3), with regular geometry, approaching parallelepipedal shapes, where the average height is below 4.0 m.","PeriodicalId":48486,"journal":{"name":"Acta Acustica","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88993812","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}
S. Dupont, Maryna Sanalatii, M. Melon, O. Robin, A. Berry, J. Le Roux
A method for measuring the diffuse field sound absorption coefficient of a material using sound field synthesis is proposed. A planar loudspeaker array is first used to generate acoustic plane waves with variable incidence angle on the surface of a material under test. Using a two-microphone probe positioned closely to the sample’s surface, the angle-dependent sound absorption coefficients are then estimated. Finally, the diffuse field absorption coefficient is computed following Paris formula. Numerical simulations are used to evaluate the respective effects of the maximum incidence angle value and the number of individual incidence angles that are required for a robust calculation of the diffuse sound field absorption. Measurements are conducted on three different materials and compared with either simulation results obtained using the Johnson-Champoux-Allard theory, or with measurement results obtained using the standard reverberation chamber method. For all considered materials and over a wide frequency range, the proposed method leads to results that are in better agreement with theoretical predictions than those obtained using standardized methods.
{"title":"Measurement of the diffuse field sound absorption using a sound field synthesis method","authors":"S. Dupont, Maryna Sanalatii, M. Melon, O. Robin, A. Berry, J. Le Roux","doi":"10.1051/aacus/2023021","DOIUrl":"https://doi.org/10.1051/aacus/2023021","url":null,"abstract":"A method for measuring the diffuse field sound absorption coefficient of a material using sound field synthesis is proposed. A planar loudspeaker array is first used to generate acoustic plane waves with variable incidence angle on the surface of a material under test. Using a two-microphone probe positioned closely to the sample’s surface, the angle-dependent sound absorption coefficients are then estimated. Finally, the diffuse field absorption coefficient is computed following Paris formula. Numerical simulations are used to evaluate the respective effects of the maximum incidence angle value and the number of individual incidence angles that are required for a robust calculation of the diffuse sound field absorption. Measurements are conducted on three different materials and compared with either simulation results obtained using the Johnson-Champoux-Allard theory, or with measurement results obtained using the standard reverberation chamber method. For all considered materials and over a wide frequency range, the proposed method leads to results that are in better agreement with theoretical predictions than those obtained using standardized methods.","PeriodicalId":48486,"journal":{"name":"Acta Acustica","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85451608","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}
Wiring, of different degrees of complexity, is a dominant part of mechanical support in constructions, electromagnetic and telecommunication signal transmission cables, among other applications. Single and manifold twisted wires are prominent examples of such utilities and are susceptible to mechanical irritations and deterioration. They require ultrasonic non-destructive testing and health monitoring. The objective is to develop an ultrasound-based technique to automatically measure the number of twists per meter in winded wire strands implementable in the industry, to be used during an ultrasonic scan and provide the number of twists per meter during cable production, for instance, to verify that calibration is still in place. Fourier transformation is applied as an expedited non-destructive testing method of twisted wires. Digital signal processing to obtain spatial and time spectral representation recognition due to amplitude variance, induced by the varying distance between the transducer and wire, is developed depending on the number of twists. Two different spatial spectral analyses satisfactorily quantify the number of twists by providing the distance between each twist. The method is robust and applicable when the distance between the transducer and strand is not constant, as the industry requires.
{"title":"Assessing the number of twists of stranded wires using ultrasound","authors":"P. Pomarède, E. T. Ahmed Mohamed, N. Declercq","doi":"10.1051/aacus/2023012","DOIUrl":"https://doi.org/10.1051/aacus/2023012","url":null,"abstract":"Wiring, of different degrees of complexity, is a dominant part of mechanical support in constructions, electromagnetic and telecommunication signal transmission cables, among other applications. Single and manifold twisted wires are prominent examples of such utilities and are susceptible to mechanical irritations and deterioration. They require ultrasonic non-destructive testing and health monitoring. The objective is to develop an ultrasound-based technique to automatically measure the number of twists per meter in winded wire strands implementable in the industry, to be used during an ultrasonic scan and provide the number of twists per meter during cable production, for instance, to verify that calibration is still in place. Fourier transformation is applied as an expedited non-destructive testing method of twisted wires. Digital signal processing to obtain spatial and time spectral representation recognition due to amplitude variance, induced by the varying distance between the transducer and wire, is developed depending on the number of twists. Two different spatial spectral analyses satisfactorily quantify the number of twists by providing the distance between each twist. The method is robust and applicable when the distance between the transducer and strand is not constant, as the industry requires.","PeriodicalId":48486,"journal":{"name":"Acta Acustica","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81380846","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}
This article aims to study the interaction of Rayleigh or surface wave with a varying angled wedge using numerical simulations. This work uses numerical tools to understand this complex problem and fills some existing gaps such as the influence of frequency and geometry of the wedge (curved vs. sharp transition). Quantitative analysis was carried out by calculating the transmission and reflection coefficients, and qualitative analysis used displacement vector plots to study the scattering and mode conversion phenomenon. The results suggest a strong dependence of transmission and reflection coefficients on the frequency and geometry of transition, which has not been reported before in the literature.
{"title":"Numerical study of Rayleigh wave interaction with wedge geometry","authors":"Alex Vu, S. Chakrapani","doi":"10.1051/aacus/2023030","DOIUrl":"https://doi.org/10.1051/aacus/2023030","url":null,"abstract":"This article aims to study the interaction of Rayleigh or surface wave with a varying angled wedge using numerical simulations. This work uses numerical tools to understand this complex problem and fills some existing gaps such as the influence of frequency and geometry of the wedge (curved vs. sharp transition). Quantitative analysis was carried out by calculating the transmission and reflection coefficients, and qualitative analysis used displacement vector plots to study the scattering and mode conversion phenomenon. The results suggest a strong dependence of transmission and reflection coefficients on the frequency and geometry of transition, which has not been reported before in the literature.","PeriodicalId":48486,"journal":{"name":"Acta Acustica","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80896313","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}
Théophile Dupré, Sébastien Denjean, M. Aramaki, R. Kronland-Martinet
In traditional combustion engine vehicles, the sound of the engine plays an important role in enhancing the driver’s experience of the vehicle’s dynamics, and contributes to both comfort and safety. However, with the development of quieter electric vehicles, drivers no longer receive this important auditory feedback, and this can lead to a less satisfying acoustic environment in the vehicle cabin. To address this issue, sonification strategies have been developed for electric vehicles to provide similar auditory feedback to the driver, but feedback from users has suggested that the sounds produced by these strategies do not blend seamlessly with the other sounds in the vehicle cabin. This study focuses on identifying the key acoustic parameters that create a sense of cohesion between the synthetic sounds and the vehicle’s natural soundscape, based on the characteristics of traditional combustion engine vehicles. Through analyzing the time and frequency of the noises produced by combustion engine vehicles, the presence of micro-modulations in both frequency and amplitude was identified, as well as resonances caused by the transfer of sound between the engine and the cabin. These parameters were incorporated into a synthesis model for the sonification of electric vehicle dynamics, based on the Shepard-Risset illusion. A perceptual test was conducted, and the results showed that the inclusion of resonances in the synthesized sounds significantly enhanced their naturalness, while micro-modulations had no significant impact.
{"title":"Analysis by synthesis of engine sounds for the design of dynamic auditory feedback of electric vehicles","authors":"Théophile Dupré, Sébastien Denjean, M. Aramaki, R. Kronland-Martinet","doi":"10.1051/aacus/2023031","DOIUrl":"https://doi.org/10.1051/aacus/2023031","url":null,"abstract":"In traditional combustion engine vehicles, the sound of the engine plays an important role in enhancing the driver’s experience of the vehicle’s dynamics, and contributes to both comfort and safety. However, with the development of quieter electric vehicles, drivers no longer receive this important auditory feedback, and this can lead to a less satisfying acoustic environment in the vehicle cabin. To address this issue, sonification strategies have been developed for electric vehicles to provide similar auditory feedback to the driver, but feedback from users has suggested that the sounds produced by these strategies do not blend seamlessly with the other sounds in the vehicle cabin. This study focuses on identifying the key acoustic parameters that create a sense of cohesion between the synthetic sounds and the vehicle’s natural soundscape, based on the characteristics of traditional combustion engine vehicles. Through analyzing the time and frequency of the noises produced by combustion engine vehicles, the presence of micro-modulations in both frequency and amplitude was identified, as well as resonances caused by the transfer of sound between the engine and the cabin. These parameters were incorporated into a synthesis model for the sonification of electric vehicle dynamics, based on the Shepard-Risset illusion. A perceptual test was conducted, and the results showed that the inclusion of resonances in the synthesized sounds significantly enhanced their naturalness, while micro-modulations had no significant impact.","PeriodicalId":48486,"journal":{"name":"Acta Acustica","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76176406","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}
M. Döllinger, Zhaoyan Zhang, S. Schoder, P. Šidlof, Bogac Tur, S. Kniesburges
Numerical modeling of the human phonatory process has become more and more in focus during the last two decades. The increase in computational power and the use of high-performance computation (HPC) yielded more complex models being closer to the actual fluid-structure-acoustic interaction (FSAI) within the human phonatory process. However, several different simulation approaches with varying mathematical complexity and focus on certain parts of the phonatory process exist. Currently, models are suggested based on ordinary differential equations (reduced order models) but also on partial differential equations based on continuum mechanics as e.g. the Navier–Stokes equations for the flow discretized by Finite-Volume or Finite-Element-Methods. This review will illuminate current trends and recent progress within the area. In summary, the ultimate simulation model satisfying all physiological needs and scientific opinions still has to be developed.
{"title":"Overview on state-of-the-art numerical modeling of the phonation process","authors":"M. Döllinger, Zhaoyan Zhang, S. Schoder, P. Šidlof, Bogac Tur, S. Kniesburges","doi":"10.1051/aacus/2023014","DOIUrl":"https://doi.org/10.1051/aacus/2023014","url":null,"abstract":"Numerical modeling of the human phonatory process has become more and more in focus during the last two decades. The increase in computational power and the use of high-performance computation (HPC) yielded more complex models being closer to the actual fluid-structure-acoustic interaction (FSAI) within the human phonatory process. However, several different simulation approaches with varying mathematical complexity and focus on certain parts of the phonatory process exist. Currently, models are suggested based on ordinary differential equations (reduced order models) but also on partial differential equations based on continuum mechanics as e.g. the Navier–Stokes equations for the flow discretized by Finite-Volume or Finite-Element-Methods. This review will illuminate current trends and recent progress within the area. In summary, the ultimate simulation model satisfying all physiological needs and scientific opinions still has to be developed.","PeriodicalId":48486,"journal":{"name":"Acta Acustica","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76714860","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}
This study describes the design considerations, principles, and performance of a water-filled ultrasonic reactor formed by a 125 mm size titanium cylinder covered with 67 piezoelectric transducers, tuned as a system for peak emissions at 500 kHz. The total acoustic power measured by a radiation force balance is 107 W. The sound intensity is amplified by the cavity and focusing attributes of the cylindrical wall. The reactor can generate ZnO nanoparticles from ZnAc2 solution, and the nanoparticle are found fixated to an epoxy substrate as observed under a scanning transmission electron microscope. These indications are similar to a sonochemical reaction reported at 20 kHz, which validates that inertial cavitation has been reached. The titanium wall has a transmission efficiency of 51% compared to a well-matched POCO graphite-resin layer. The efficiency exceeds the value of 17% expected from a naïve calculation based on the impedance-translation theorem. The problem of optimal emission from a piezoelectric source is more complex than a simple reduction of reflections at the transducer boundary. COMSOL simulations show that the condition for optimal transmission requires consideration of elasticity and piezoelectric charge matrices instead of acoustic impedance. Approximated analytical calculation is suggested as a preliminary guidance for design of an optimal matching layer.
{"title":"Titanium ultrasonic reactor tuned to 500 kHz","authors":"Shahar Seifer","doi":"10.1051/aacus/2023001","DOIUrl":"https://doi.org/10.1051/aacus/2023001","url":null,"abstract":"This study describes the design considerations, principles, and performance of a water-filled ultrasonic reactor formed by a 125 mm size titanium cylinder covered with 67 piezoelectric transducers, tuned as a system for peak emissions at 500 kHz. The total acoustic power measured by a radiation force balance is 107 W. The sound intensity is amplified by the cavity and focusing attributes of the cylindrical wall. The reactor can generate ZnO nanoparticles from ZnAc2 solution, and the nanoparticle are found fixated to an epoxy substrate as observed under a scanning transmission electron microscope. These indications are similar to a sonochemical reaction reported at 20 kHz, which validates that inertial cavitation has been reached. The titanium wall has a transmission efficiency of 51% compared to a well-matched POCO graphite-resin layer. The efficiency exceeds the value of 17% expected from a naïve calculation based on the impedance-translation theorem. The problem of optimal emission from a piezoelectric source is more complex than a simple reduction of reflections at the transducer boundary. COMSOL simulations show that the condition for optimal transmission requires consideration of elasticity and piezoelectric charge matrices instead of acoustic impedance. Approximated analytical calculation is suggested as a preliminary guidance for design of an optimal matching layer.","PeriodicalId":48486,"journal":{"name":"Acta Acustica","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76299232","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}
Roman Kiyan, Jakob Bergner, Stephan Preihs, Yves Wycisk, Daphne Schössow, Kilian Sander, Jürgen Peissig, Reinhard Kopiez
When evaluating surround sound loudspeaker reproduction, perceptual effects are commonly analyzed in relationship to different loudspeaker configurations. The presented work contributes to this by modeling perceptual effects based on acoustic properties of various reproduction formats. A model of immersion in music listening is derived from the results of an experimental study analyzing the psychological construct of immersive music experience. The proposed approach is evaluated with respect to the relationship between immersion ratings and sound field features obtained from re-recordings of the stimuli using a spherical microphone array at the listening position. Spatial sound field parameters such as inter-aural cross-correlation (IACC), diffuseness and directivity are found to be of particular relevance. Further, immersion is observed to reach a point of saturation with greater numbers of loudspeakers, which is confirmed to be predictable from the physical properties of the sound field. Although effects related to participants and musical pieces outweigh the impact of sound field features, the proposed approach is found to be suitable for predicting population-average ratings, i.e. immersion experienced by an average listener for unknown content. The proposed method could complement existing research on multichannel loudspeaker reproduction by establishing a more generalizable framework independent of particular speaker setups.
{"title":"Towards predicting immersion in surround sound music reproduction from sound field features","authors":"Roman Kiyan, Jakob Bergner, Stephan Preihs, Yves Wycisk, Daphne Schössow, Kilian Sander, Jürgen Peissig, Reinhard Kopiez","doi":"10.1051/aacus/2023040","DOIUrl":"https://doi.org/10.1051/aacus/2023040","url":null,"abstract":"When evaluating surround sound loudspeaker reproduction, perceptual effects are commonly analyzed in relationship to different loudspeaker configurations. The presented work contributes to this by modeling perceptual effects based on acoustic properties of various reproduction formats. A model of immersion in music listening is derived from the results of an experimental study analyzing the psychological construct of immersive music experience. The proposed approach is evaluated with respect to the relationship between immersion ratings and sound field features obtained from re-recordings of the stimuli using a spherical microphone array at the listening position. Spatial sound field parameters such as inter-aural cross-correlation (IACC), diffuseness and directivity are found to be of particular relevance. Further, immersion is observed to reach a point of saturation with greater numbers of loudspeakers, which is confirmed to be predictable from the physical properties of the sound field. Although effects related to participants and musical pieces outweigh the impact of sound field features, the proposed approach is found to be suitable for predicting population-average ratings, i.e. immersion experienced by an average listener for unknown content. The proposed method could complement existing research on multichannel loudspeaker reproduction by establishing a more generalizable framework independent of particular speaker setups.","PeriodicalId":48486,"journal":{"name":"Acta Acustica","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135799098","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}
This study examined how talker accentedness affects the recognition of noise-vocoded speech by native English listeners and how contextual information interplays with talker accentedness during this process. The listeners included 20 native English-speaking, normal-hearing adults aged between 19 and 23 years old. The stimuli were English Hearing in Noise Test (HINT) and Revised Speech Perception in Noise (R-SPIN) sentences produced by four native Mandarin talkers (two males and two females) who learned English as a second language. Two talkers (one in each sex) had a mild foreign accent and the other two had a moderate foreign accent. A six-channel noise vocoder was used to process the stimulus sentences. The vocoder-processed and unprocessed sentences were presented to the listeners. The results revealed that talkers’ foreign accents introduced additional detrimental effects besides spectral degradation and that the negative effect was exacerbated as the foreign accent became stronger. While the contextual information provided a beneficial role in recognizing mildly accented vocoded speech, the magnitude of contextual benefit decreased as the talkers’ accentedness increased. These findings revealed the joint influence of talker variability and sentence context on the perception of degraded speech.
{"title":"Recognition of foreign-accented vocoded speech by native English listeners","authors":"Jing Yang, Jenna Barrett, Zhigang Yin, Li Xu","doi":"10.1051/aacus/2023038","DOIUrl":"https://doi.org/10.1051/aacus/2023038","url":null,"abstract":"This study examined how talker accentedness affects the recognition of noise-vocoded speech by native English listeners and how contextual information interplays with talker accentedness during this process. The listeners included 20 native English-speaking, normal-hearing adults aged between 19 and 23 years old. The stimuli were English Hearing in Noise Test (HINT) and Revised Speech Perception in Noise (R-SPIN) sentences produced by four native Mandarin talkers (two males and two females) who learned English as a second language. Two talkers (one in each sex) had a mild foreign accent and the other two had a moderate foreign accent. A six-channel noise vocoder was used to process the stimulus sentences. The vocoder-processed and unprocessed sentences were presented to the listeners. The results revealed that talkers’ foreign accents introduced additional detrimental effects besides spectral degradation and that the negative effect was exacerbated as the foreign accent became stronger. While the contextual information provided a beneficial role in recognizing mildly accented vocoded speech, the magnitude of contextual benefit decreased as the talkers’ accentedness increased. These findings revealed the joint influence of talker variability and sentence context on the perception of degraded speech.","PeriodicalId":48486,"journal":{"name":"Acta Acustica","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135495425","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}
Fabio Di Giusto, Sjoerd van Ophem, Wim Desmet, Elke Deckers
Individual Head-Related Transfer Functions (HRTFs) are necessary for the accurate rendering of virtual scenes. However, their acquisition is challenging given the complex pinna shape. Numerical methods can be leveraged to compute HRTFs on meshes originating from precise scans of a subject. Although photogrammetry can be used for the scanning, its inaccuracy might affect the spatial cues of simulated HRTFs. This paper aims to assess the significance of the photogrammetric error affecting a Neumann KU100 dummy head scan. The geometrical differences between the photogrammetric scan and a laser scan are mainly located at the pinna cavities. The computed photogrammetric HRTFs, compared to measured and simulated data using objective and perceptually inspired metrics, show deviation in high frequency spectral features, stemming from the photogrammetric scanning error. This spectral deviation hinders the modelled elevation perception with photogrammetric HRTFs to levels comparable to renderings with nonindividual data. Extracting the photogrammetric geometry at individual ear cavities and merging it to the laser mesh, an assessment of the influence of the inaccuracy at different pinna structures is conducted. Correlation analysis between acoustic and geometrical metrics computed on the results is used to identify the most relevant geometrical metrics in relation to the HRTFs.
{"title":"Analysis of laser scanning and photogrammetric scanning accuracy on the numerical determination of Head-Related Transfer Functions of a dummy head","authors":"Fabio Di Giusto, Sjoerd van Ophem, Wim Desmet, Elke Deckers","doi":"10.1051/aacus/2023049","DOIUrl":"https://doi.org/10.1051/aacus/2023049","url":null,"abstract":"Individual Head-Related Transfer Functions (HRTFs) are necessary for the accurate rendering of virtual scenes. However, their acquisition is challenging given the complex pinna shape. Numerical methods can be leveraged to compute HRTFs on meshes originating from precise scans of a subject. Although photogrammetry can be used for the scanning, its inaccuracy might affect the spatial cues of simulated HRTFs. This paper aims to assess the significance of the photogrammetric error affecting a Neumann KU100 dummy head scan. The geometrical differences between the photogrammetric scan and a laser scan are mainly located at the pinna cavities. The computed photogrammetric HRTFs, compared to measured and simulated data using objective and perceptually inspired metrics, show deviation in high frequency spectral features, stemming from the photogrammetric scanning error. This spectral deviation hinders the modelled elevation perception with photogrammetric HRTFs to levels comparable to renderings with nonindividual data. Extracting the photogrammetric geometry at individual ear cavities and merging it to the laser mesh, an assessment of the influence of the inaccuracy at different pinna structures is conducted. Correlation analysis between acoustic and geometrical metrics computed on the results is used to identify the most relevant geometrical metrics in relation to the HRTFs.","PeriodicalId":48486,"journal":{"name":"Acta Acustica","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134883409","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}