Acta Acustica united with Acustica最新文献

{"title":"Anthropogenic Noise Mapping of a Periurban Natural Park on the Coastal Area in the SW of Spain: Case Study of Bird's Ecosystem Protection","authors":"J. Cueto, D. Bienvenido-Huertas, Francisco Fernández-Zacarías, Ricardo Gey, Ricardo Hernández-Molina","doi":"10.3813/aaa.919380","DOIUrl":"https://doi.org/10.3813/aaa.919380","url":null,"abstract":"This article presents a methodological approach to try to respond to some of the protection and management needs against the noise of a peri-urban natural park. The methodology presented is based on the generation of \"ad hoc\" noise maps. To analyze its possibilities and the limits of\u0000 use, a coastal park surrounded by a densely populated area in the southwest of Spain is used as a case study. In this study, birds in their diverse ecosystems are the main target noise receiver of the study. The source of noise pollution considered is the traffic noise of the highways and\u0000 the urbanized areas surrounding the park. However, the methodology can be extrapolated to any source of noise and other protection figures. An adequate diagnosis of the environmental noise would help to overcome the supposed incompatibility between the preservation of nature and the tourist\u0000 exploitation of natural spaces. With this in mind, it has also been proposed as target noise receivers, the ornithologists and visitors who wish to become bird-watchers and bird-listeners. To this end, it has been proposed to produce noise maps with certain methodological guidelines that fit\u0000 on a case-by-case basis. Several heights are used in this paper, adapting the map to noise receivers. With the same purpose, noise level maps in octave bands were developed. The tonal frequencies of interest are those that the birds use in their songs (according to the species, normally between\u0000 2 and 8 kHz). The maps have been contrasted with noise measurements carried out throughout the park. The study shows that in the areas most exposed to the noise of the Rio San Pedro and the university campus, noise levels at 2 kHz can reach 74 dB during the peak traffic hours. In addition,\u0000 a large percentage of the area of both areas is affected by noise levels that exceed 50 dB (100% and 44% respectively). We are also concerned that a small population of birds has been counted in these areas based on preliminary observations at peak traffic times. The results can help the decision-makers\u0000 to evaluate how traffic noise invades different ecosystems and where it can mask the sound of birds.","PeriodicalId":35085,"journal":{"name":"Acta Acustica united with Acustica","volume":"43 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87869203","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}

{"title":"Acoustical Classification of the Urban Road Traffic with Large Arrays of Microphones","authors":"R. Leiba, F. Ollivier, R. Marchiano, N. Misdariis, J. Marchal, P. Challande","doi":"10.3813/aaa.919385","DOIUrl":"https://doi.org/10.3813/aaa.919385","url":null,"abstract":"This work is part of a study dealing with city-dwellers' quality of life. Noise is known to be an important factor influencing the quality of life. In order to diagnose it properly, we propose a noise monitoring system of urban areas. It is based on the use of large microphone arrays\u0000 in order to extract the radiated sound field from each passing-by vehicle in typical urban scenes. A machine learning algorithm is trained so as to classify these extracted signals in clusters combining both the vehicle type and the driving conditions. This system makes it possible to monitor\u0000 the evolution of the noise levels for each cluster. The proposed system was first tested on passing-by isolated vehicles measurements and then implemented in a real street in Paris (France).","PeriodicalId":35085,"journal":{"name":"Acta Acustica united with Acustica","volume":"5 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76371642","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}

{"title":"Rating Level as a Method to Assess the Impact of Speech Noise on Cognitive Performance and Annoyance in Offices","authors":"T. Renz, P. Leistner, Andreas Liebl","doi":"10.3813/aaa.919390","DOIUrl":"https://doi.org/10.3813/aaa.919390","url":null,"abstract":"In Germany, the rating level is an important parameter to assess noise immissions in occupied offices. The rating level denotes the energy-equivalent sound pressure level during a measurement period with speech sounds and considers penalties for tonal, informational and impulsive constituents.\u0000 There is little evidence that the rating level correlates with the performance and perceived annoyance of office workers. This study evaluates 89 different sound conditions under which subjects have to complete a short-term memory task and a questionnaire in laboratory conditions with respect\u0000 to their relationships with the rating level. The relationships of the penalty for impulsiveness and the penalty for tonality or informational constituents with the rating level are analyzed separately. In addition, the penalty for tonality or informational constituents is substituted by percentile\u0000 level statistics, namely the difference between the 10th and 90th percentile levels. In contrast to the penalty for tonality or informational constituents, this metric is objectively measurable. Using the rating level to assess the noise at office workplaces could be\u0000 improved by using percentile level statistics to account for informational constituents. To improve the predictive validity, it is suggested to report the penalties separately.","PeriodicalId":35085,"journal":{"name":"Acta Acustica united with Acustica","volume":"7 2 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77494001","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}

{"title":"Suppression of Lateral Vibration in Rectangular Ultrasonic Plastic Soldering Tool Based on Phononic Crystal Structure","authors":"T. Zhao, Shu-Yu Lin","doi":"10.3813/aaa.919376","DOIUrl":"https://doi.org/10.3813/aaa.919376","url":null,"abstract":"In this paper, the design of large-size rectangular ultrasonic plastic soldering system is studied by using the band gap theory of phononic crystal and coupled vibration theory of large-size rectangular tool. In practical engineering applications, lateral vibration of the large-size\u0000 rectangular tool will seriously cause the displacement of the tool's radiation surface uneven. So the lateral vibration of the tool should be suppressed. As we all know, phononic crystal materials can suppress the vibration and they are composed of two or more different materials periodically\u0000 (including matrix material and scattering material). This paper uses periodic slotted structure to suppress the lateral vibration of the large-size rectangular tool. The lateral vibration band gap of the large-size rectangular tool which has periodic slotted structure in this paper is simulated.\u0000 In addition, the influence of the scatterer's size on the lateral vibration band gap is also obtained. At the same time, the magnitude and uniformity of the tool's radiation surface displacement before and after slotting is compared in experiments. The research shows that by reasonably designing\u0000 the periodic structure and size of the phononic crystal, the lateral vibration of the large-size rectangular tool can be effectively suppressed, and the displacement of the tool's radiation surface can be more even.","PeriodicalId":35085,"journal":{"name":"Acta Acustica united with Acustica","volume":"7 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81942807","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}

{"title":"Solving Galbrun's Equation with a Discontinuous galerkin Finite Element Method","authors":"M. Maeder, A. Peplow, M. Meindl, S. Marburg","doi":"10.3813/aaa.919369","DOIUrl":"https://doi.org/10.3813/aaa.919369","url":null,"abstract":"Over many years, scientists and engineers have developed a broad variety of mathematical formulations to investigate the propagation and interactions with flow of flow-induced noise in early-stage of product design and development. Beside established theories such as the linearized\u0000 Euler equations (LEE), the linearized Navier–Stokes equations (LNSE) and the acoustic perturbation equations (APE) which are described in an Eulerian framework, Galbrun utilized a mixed Lagrange–Eulerian framework to reduce the number of unknowns by representing perturbations by\u0000 means of particle displacement only. Despite the advantages of fewer degrees of freedom and the reduced effort to solve the system equations, a computational approach using standard continuous finite element methods (FEM) suff ers from instabilities called spurious modes that pollute the solution.\u0000 In this work, the authors employ a discontinuous Galerkin approach to overcome the difficulties related to spurious modes while solving Galbrun's equation in a mixed and pure displacement based formulation. The results achieved with the proposed approach are compared with results from previous\u0000 attempts to solve Galbrun's equation. The numerical determination of acoustic modes and the identification of vortical modes is discussed. Furthermore, case studies for a lined-duct and an annulus supporting a rotating shear-flow are investigated.","PeriodicalId":35085,"journal":{"name":"Acta Acustica united with Acustica","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79690039","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}

{"title":"Measurement of \"Reed to Room\"-Transfer Functions","authors":"T. Grothe, S. V. A. Garí","doi":"10.3813/aaa.919370","DOIUrl":"https://doi.org/10.3813/aaa.919370","url":null,"abstract":"A method is proposed here to synthesize the acoustic response of a room to a musical reed wind instrument with tone holes played by a musician. The procedure uses convolution of a) two measured pulse responses and b) the mouthpiece pressure during playing. The novelty of the approach\u0000 is to include the sound radiation directivity of the source in the impulse response measurement of the room by using the wind instrument's air column as an exciter. At the reed input end of the air column pressure pulses at typical peak pressures of several kilopascals are generated using\u0000 a compressor and a solenoid valve, which provides a high SNR even at distant measurement positions. For auralization purpose, the source signal measurement is done very close to the sound generation locus, i.e. inside the mouthpiece. Because this measurement is largely insensitive to room\u0000 acoustics, the proposed method can be considered a very convenient alternative to music recordings in anechoic conditions. As a proof of concept we report here experimental results for the case of a bassoon. The method can be extended to auralizations of reed and lip-reed musical instruments\u0000 in virtual acoustic scenes, and sheds light on the importance of the reflective and radiative properties of the air column for the sound coloration.","PeriodicalId":35085,"journal":{"name":"Acta Acustica united with Acustica","volume":"101 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77226765","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}

{"title":"Performance of a Low-Height Acoustic Screen for Urban Roads: Field Measurement and Numerical Study","authors":"Jens Forssén, Laura Estévez Mauriz, Clas Torehammar, P. Jean, Östen Axelsson","doi":"10.3813/aaa.919381","DOIUrl":"https://doi.org/10.3813/aaa.919381","url":null,"abstract":"Field measurements and numerical modelling were used to study the acoustic performance of a low screen in an urban road setting. The results show the usefulness of low screens as well as suggests improvements in screen design. For the measurements, an acoustic screen built up from concrete\u0000 modules was temporarily installed beside a small park on the reservation between a two-lane road and a track for walking and cycling. A larger traffic system, of which the two-lane road is a part, determines the daytime equivalent noise level within the urban area. The screen height was about\u0000 1.4 m as measured from the level of the road surface and the width of the screen top was 0.3 m. Measurements were carried out both at 20 m distance from the road (within the park) and at 5 m distance from the road (at the cycle track). Insertion loss in maximum level, using controlled lightvehicle\u0000 pass-by at 50 km/h, was measured to 10 dB at 5 m distance and to 6 dB at 20 m distance, at 1.5 m height. Insertion loss in equivalent level was measured within the park to 4 dB at 1.5 m height. A listening experiment confirmed a perceived improvement from installing the screen. The measured\u0000 results were also compared with predicted results using a boundary element method (BEM) and a noise mapping software, the latter showing good agreement, overestimating the equivalent level insertion loss by 1 dB in the park. The BEM comparison showed reasonable agreement in maximum level insertion\u0000 loss considering that facade reflections were excluded, with an overestimation of 5 dB at the cycle track, and good agreement in the park, overestimating by up to 1 dB the equivalent and maximum level insertion losses. BEM predictions were used to also investigate other screen designs, showing\u0000 a positive effect of an acoustically soft screen top, significant for a screen width of 0.2 m and increasing for wider screens.","PeriodicalId":35085,"journal":{"name":"Acta Acustica united with Acustica","volume":"23 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82527857","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}

{"title":"A Canonicalization of Distinctive Phonetic Features to Improve Arabic Speech Recognition","authors":"Y. Alotaibi, S. Selouani, M. S. Yakoub, Yasser M. Seddiq, A. Meftah","doi":"10.3813/aaa.919404","DOIUrl":"https://doi.org/10.3813/aaa.919404","url":null,"abstract":"The robustness of speech classification and recognition systems can be improved by the adoption of language distinctive phonetic feature (DPF) elements that can increase the effective characterization of a speech signal. This paper presents the results of applying Hidden Markov Models\u0000 (HMMs) that perform Arabic phoneme recognition in conjunction with the inclusion and classification of their DPF element classes. The research focuses on classifying Modern Standard Arabic (MSA) phonemes within isolated words without a language context. HMM-based phoneme recognition is tested\u0000 using 8, 16, and 32 HMM Gaussian mixture models. The monophone configuration is designed with consideration of 2-gram language model to evaluate the inherent performance of the system. The overall correct rates for classifying DPF element classes for the three versions of HMM systems are 83.29%\u0000 88.96%, and 92.70% for 8, 16, and 32 HMM Gaussian mixture model systems, respectively.","PeriodicalId":35085,"journal":{"name":"Acta Acustica united with Acustica","volume":"6 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90699054","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}

{"title":"Compressive Spherical Beamforming for Acoustic Source Identification","authors":"Guoli Ping, Zhigang Chu, Yang Yang","doi":"10.3813/aaa.919406","DOIUrl":"https://doi.org/10.3813/aaa.919406","url":null,"abstract":"This study examines a compressive spherical beamforming (CSB) method, using a rigid spherical microphone array to localize and quantify the acoustic contribution of sources. The method relies on the array signal model in the spherical harmonics domain that can be represented as a spatially\u0000 sparse problem. This makes it possible to use compressive sensing to solve an underdetermined problem via promoting sparsity. The estimation of the angular position of sources with respect to the microphone array, as well as the three-dimensional localization over a volume are investigated.\u0000 Several sparse recovery algorithms [orthogonal matching pursuit (OMP), generalized OMP, ϱ1-norm minimization, and reweighted ϱ1-norm minimization] are examined for this purpose. The numerical and experimental results indicate that sparse\u0000 recovery methods outperform conventional spherical harmonics beamforming. Reweighted ϱ1-norm has good adaptability to noise, improving the robustness of CSB. The method can successfully localize the angular position of sources, and quantify their relative pressure\u0000 contribution. The method is promising to localize sources in a three-dimensional domain of interest. However, the three-dimensional localization is more sensitive to noise, source distance, and properties of the sensing matrix than the two-dimensional localization.","PeriodicalId":35085,"journal":{"name":"Acta Acustica united with Acustica","volume":"60 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84186252","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}

{"title":"Acoustic Scattering from Bi-Layered Cylindrical Shells: Influence of the Layers Thicknesses on the Guided Waves","authors":"Y. Khandouch, E. Aassif, S. Agounad","doi":"10.3813/aaa.919402","DOIUrl":"https://doi.org/10.3813/aaa.919402","url":null,"abstract":"The current work focuses on the study of acoustic scattering from bi-layered stainless steel-copper and copper-stainless steel cylindrical shells filled with air and immersed in water. This paper is interested in revealing the effects of physical and geometrical characteristics of the\u0000 layers constituting the shells on the scattering phenomenon. The object of this work, is to study the influence of the layers thicknesses on guided waves, the overall thickness of the shells is fixed. The plane of modal identification was chosen to analyze the scattering phenomenon. We investigate\u0000 the resonance trajectories of the guided waves, especially the curves change. The investigation and comparison made on resonance trajectories, show a shape change, a gradual deviation, or both, appear on the resonance trajectories of different guided waves, for the reduced cutoff frequencies\u0000 of guided waves a sliding to higher and lower value are noticed. The interaction between guided waves is also manifested in the scattering phenomenon. The findings for the bi-layered cylindrical shells are then compared with those obtained for the mono-layered stainless steel and copper cylindrical\u0000 shells. Then, this work is completed by an investigation on the reduced cut-off frequencies of the A1 wave, that have been extracted for different possible values of the intermediary radius. In this part, to understand the observed phenomena, other examples of bi-layered\u0000 cylindrical shells are introduced. The obtained results are analyzed and investigated.","PeriodicalId":35085,"journal":{"name":"Acta Acustica united with Acustica","volume":"75 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88024104","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}