Download or read book Uncertainties in Acoustical Transfer Functions written by Pascal Dietrich and published by Logos Verlag Berlin GmbH. This book was released on 2013 with total page 220 pages. Available in PDF, EPUB and Kindle. Book excerpt: Measured transfer functions of acoustic systems are often used to derive single-number parameters. The uncertainty analysis is commonly focused on the derived parameters but not on the transfer function as the primary quantity. This thesis presents an approach to assess the uncertainty contributions in these transfer functions by using analytic models. Uncertainties caused by the measurement method are analyzed with a focus on the underlying signal processing. In particular, the influence of nonlinearities in the acoustic measurement chain are modeled to predict artifacts in the measured signals and hence the calculated acoustic transfer function. Secondly, characterization methods commonly applied in the field of signal processing are linked to the acoustic scenarios and the main influencing parameters. Acoustic parameters are then derived analytically and by means of Monte Carlo simulations considering the uncertainty of these input parameters. In order to provide airborne applications, analytic models for sound barrier and room acoustic measurements are developed incorporating the directivity and the orientation of the sound source as well as the positions of sources and receivers. The simulated uncertainty contributions are validated by measurements. The same approach is also applied to structure-borne sound applications.

Download or read book Anthropometric Individualization of Head Related Transfer Functions Analysis and Modeling written by Ramona Bomhardt and published by Logos Verlag Berlin GmbH. This book was released on 2017-09-04 with total page 162 pages. Available in PDF, EPUB and Kindle. Book excerpt: Human sound localization helps to pay attention to spatially separated speakers using interaural level and time differences as well as angle-dependent monaural spectral cues. In a monophonic teleconference, for instance, it is much more difficult to distinguish between different speakers due to missing binaural cues. Spatial positioning of the speakers by means of binaural reproduction methods using head-related transfer functions (HRTFs) enhances speech comprehension. These HRTFs are influenced by the torso, head and ear geometry as they describe the propagation path of the sound from a source to the ear canal entrance. Through this geometry-dependency, the HRTF is directional and subject-dependent. To enable a sufficient reproduction, individual HRTFs should be used. However, it is tremendously difficult to measure these HRTFs. For this reason this thesis proposes approaches to adapt the HRTFs applying individual anthropometric dimensions of a user. Since localization at low frequencies is mainly influenced by the interaural time difference, two models to adapt this difference are developed and compared with existing models. Furthermore, two approaches to adapt the spectral cues at higher frequencies are studied, improved and compared. Although the localization performance with individualized HRTFs is slightly worse than with individual HRTFs, it is nevertheless still better than with non-individual HRTFs, taking into account the measurement effort.

Download or read book European Conference on Underwater Acoustics written by M. Weydert and published by CRC Press. This book was released on 2004-01-14 with total page 786 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book represents the proceedings of the Conference on Underwater Acoustics, held in September 1992, to bring together all the various disciplines involved in a forum to present the latest research on all aspects of marine acoustics.

Download or read book GB Z 27764 2011 Translated English of Chinese Standard GB Z 27764 2011 GBZ27764 2011 written by https://www.chinesestandard.net and published by https://www.chinesestandard.net. This book was released on 2023-06-25 with total page 41 pages. Available in PDF, EPUB and Kindle. Book excerpt: This guiding technical document stipulates the measurement of normal incidence sound insulation (or normal incidence sound transmission loss) of acoustic materials or acoustic structures, in impedance tubes, by using the transfer matrix method. This guiding technical document is applicable to the measurement of the normal incidence sound insulation of locally reactive acoustic materials, such as sponges, cotton felts, soft thin plates, whose test frequency is in the quality control area (that is, there is no sound propagation parallel to the material inside the material). It is applicable to the comparison of sound insulation performance of acoustic materials, in the development stage. Since the sound transmission loss of a material is closely related to its physical properties (such as elastic modulus, density, structure factor, etc.), the measurement methods specified in this guiding technical document can be applied to relevant basic research and product development. This guiding technical document is not applicable to the identification test of the sound insulation performance of the product. This guiding technical document uses an impedance tube, one or more microphones, and a digital acquisition & analysis system.

Download or read book Uncertainty in Acoustics written by Robert Peters and published by CRC Press. This book was released on 2020-07-27 with total page 467 pages. Available in PDF, EPUB and Kindle. Book excerpt: This guide to estimating uncertainties in the measurement, prediction and assessment of noise and vibration applies across environmental noise and vibration, occupational noise and vibration exposure, and building and architectural acoustics. The book collates information from the various Standards and from research, with explanation, examples and case studies. It enables estimation of uncertainty in the measurement and prediction of acoustic quantities, suitable for use in environmental impact and occupational exposure assessments. It is for acoustic consultants, mechanical and building service engineers, architect and building professionals and environmental health officers. Bob Peters worked for more than forty years in acoustics and noise control – teaching, research, consultancy. He was a principal acoustic consultant with Applied Acoustic Design, a senior research fellow at London South Bank University, and a tutor on Institute of Acoustics distance learning courses.

Download or read book IUTAM Symposium on the Vibration Analysis of Structures with Uncertainties written by Alexander K. Belyaev and published by Springer Science & Business Media. This book was released on 2010-12-02 with total page 471 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Symposium was aimed at the theoretical and numerical problems involved in modelling the dynamic response of structures which have uncertain properties due to variability in the manufacturing and assembly process, with automotive and aerospace structures forming prime examples. It is well known that the difficulty in predicting the response statistics of such structures is immense, due to the complexity of the structure, the large number of variables which might be uncertain, and the inevitable lack of data regarding the statistical distribution of these variables. The Symposium participants presented the latest thinking in this very active research area, and novel techniques were presented covering the full frequency spectrum of low, mid, and high frequency vibration problems. It was demonstrated that for high frequency vibrations the response statistics can saturate and become independent of the detailed distribution of the uncertain system parameters. A number of presentations exploited this physical behaviour by using and extending methods originally developed in both phenomenological thermodynamics and in the fields of quantum mechanics and random matrix theory. For low frequency vibrations a number of presentations focussed on parametric uncertainty modelling (for example, probabilistic models, interval analysis, and fuzzy descriptions) and on methods of propagating this uncertainty through a large dynamic model in an effi cient way. At mid frequencies the problem is mixed, and various hybrid schemes were proposed. It is clear that a comprehensive solution to the problem of predicting the vibration response of uncertain structures across the whole frequency range requires expertise across a wide range of areas (including probabilistic and non-probabilistic methods, interval and info-gap analysis, statistical energy analysis, statistical thermodynamics, random wave approaches, and large scale computations) and this IUTAM symposium presented a unique opportunity to bring together outstanding international experts in these fields.

Download or read book Rotating Machinery Vibro Acoustics Laser Vibrometry Volume 7 written by Dario Di Maio and published by Springer. This book was released on 2018-06-04 with total page 244 pages. Available in PDF, EPUB and Kindle. Book excerpt: Rotating Machinery, Vibro-Acoustics & Laser Vibrometry, Volume 7: Proceedings of the 36th IMAC, A Conference and Exposition on Structural Dynamics, 2018, the seveth volume of nine from the Conference brings together contributions to this important area of research and engineering. The collection presents early findings and case studies on fundamental and applied aspects of Rotating Machinery, Hybrid Testing, Vibro-Acoustics & Laser Vibrometry, including papers on: Rotating Machinery Vibro-Acoustics Experimental Techniques Scanning Laser Doppler Vibrometry Methods

Download or read book Adaptive Feed Forward Control of Low Frequency Interior Noise written by Thomas Kletschkowski and published by Springer Science & Business Media. This book was released on 2011-10-29 with total page 352 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents a mechatronic approach to Active Noise Control (ANC). It describes the required elements of system theory, engineering acoustics, electroacoustics and adaptive signal processing in a comprehensive, consistent and systematic manner using a unified notation. Furthermore, it includes a design methodology for ANC-systems, explains its application and describes tools to be used for ANC-system design. From the research point of view, the book presents new approaches to sound source localization in weakly damped interiors. One is based on the inverse finite element method, the other is based on a sound intensity probe with an active free field. Furthermore, a prototype of an ANC-system able to reach the physical limits of local (feed-forward) ANC is described. This is one example for applied research in ANC-system design. Other examples are given for (i) local ANC in a semi-enclosed subspace of an aircraft cargo hold and (ii) for the combination of audio entertainment with ANC.

Download or read book Sound Reinforcement for Audio Engineers written by Wolfgang Ahnert and published by CRC Press. This book was released on 2022-08-31 with total page 450 pages. Available in PDF, EPUB and Kindle. Book excerpt: Sound Reinforcement for Audio Engineers illustrates the current state of the art in sound reinforcement. Beginning with an outline of various fields of applications, from sports venues to religious venues, corporate environments and cinemas, this book is split into 11 chapters covering room acoustics, loudspeakers, microphones and acoustic modelling among many other topics. This comprehensive book packed with references and a historical overview of sound reinforcement design is an essential reference book for students of acoustics and electrical engineering, but also for engineers looking to expand their knowledge of designing sound reinforcement systems.

Download or read book Automotive Tire Noise and Vibrations written by Xu Wang and published by Butterworth-Heinemann. This book was released on 2020-07-29 with total page 400 pages. Available in PDF, EPUB and Kindle. Book excerpt: Automotive Tire Noise and Vibrations: Analysis, Measurement and Simulation presents the latest generation mechanisms of tire/road noise. The book focuses not only on tire/road noise issues from the tire/road structures, materials and dynamics, but also from a whole vehicle system. The analyses cover finite element modeling, mathematical simulations and experimental tests, including works done to mitigate noise. This book provides a summary of tire noise and vibration research, with a focus on new simulation and measurement techniques. Covers new measurements techniques and simulation strategies that are critical in accurately assessing tire noise and vibration Provides recent simulation progress and findings of CAE on analysis of generation mechanisms of the tire/road noise Features a Statistical Energy Analysis (SEA) and model of a multilayer trim to enhance the sound absorption of tire/road noise

Download or read book Engineering Vibroacoustic Analysis written by Stephen A. Hambric and published by John Wiley & Sons. This book was released on 2016-02-18 with total page 536 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book describes analytical methods (based primarily on classical modal synthesis), the Finite Element Method (FEM), Boundary Element Method (BEM), Statistical Energy Analysis (SEA), Energy Finite Element Analysis (EFEA), Hybrid Methods (FEM-SEA and Transfer Path Analysis), and Wave-Based Methods. The book also includes procedures for designing noise and vibration control treatments, optimizing structures for reduced vibration and noise, and estimating the uncertainties in analysis results. Written by several well-known authors, each chapter includes theoretical formulations, along with practical applications to actual structural-acoustic systems. Readers will learn how to use vibroacoustic analysis methods in product design and development; how to perform transient, frequency (deterministic and random), and statistical vibroacoustic analyses; and how to choose appropriate structural and acoustic computational methods for their applications. The book can be used as a general reference for practicing engineers, or as a text for a technical short course or graduate course.

Download or read book Model Validation and Uncertainty Quantification Volume 3 written by Zhu Mao and published by Springer Nature. This book was released on 2022-07-01 with total page 151 pages. Available in PDF, EPUB and Kindle. Book excerpt: Model Validation and Uncertainty Quantification, Volume 3: Proceedings of the 40th IMAC, A Conference and Exposition on Structural Dynamics, 2022, the third volume of nine from the Conference brings together contributions to this important area of research and engineering. The collection presents early findings and case studies on fundamental and applied aspects of Model Validation and Uncertainty Quantification, including papers on: Uncertainty Quantification and Propagation in Structural Dynamics Bayesian Analysis for Real-Time Monitoring and Maintenance Uncertainty in Early Stage Design Quantification of Model-Form Uncertainties Fusion of Test and Analysis MVUQ in Action

Download or read book Handbook of Noise and Vibration Control written by Malcolm J. Crocker and published by John Wiley & Sons. This book was released on 2007-10-05 with total page 1594 pages. Available in PDF, EPUB and Kindle. Book excerpt: Two of the most acclaimed reference works in the area of acoustics in recent years have been our Encyclopedia of Acoustics, 4 Volume set and the Handbook of Acoustics spin-off. These works, edited by Malcolm Crocker, positioned Wiley as a major player in the acoustics reference market. With our recently published revision of Beranek & Ver's Noise and Vibration Control Engineering, Wiley is a highly respected name in the acoustics business. Crocker's new handbook covers an area of great importance to engineers and designers. Noise and vibration control is one largest areas of application of the acoustics topics covered in the successful encyclopedia and handbook. It is also an area that has been under-published in recent years. Crocker has positioned this reference to cover the gamut of topics while focusing more on the applications to industrial needs. In this way the book will become the best single source of need-to-know information for the professional markets.

Download or read book Combined Wave and Ray Based Room Acoustic Simulations of Small Rooms written by Marc Aretz and published by Logos Verlag Berlin GmbH. This book was released on 2012 with total page 221 pages. Available in PDF, EPUB and Kindle. Book excerpt: The present thesis establishes a complete framework for the combination of finite element and classical ray based acoustic simulations in small rooms and discusses the inherent challenges and limitations including all aspects of sound generation, sound reflection and sound reception. In this context, the thesis gives detailed guidelines for the best-possible determination of all necessary input data for both simulation domains. The overall potential of the presented combined approach is assessed by conducting extensive objective and subjective comparisons of measurement and simulation results for three types of acoustically relevant small spaces (a scale-model reverberation room, a recording studio and two different car passenger compartments).

Download or read book Sound and Music Computing written by Tapio Lokki and published by MDPI. This book was released on 2018-06-26 with total page 621 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is a printed edition of the Special Issue "Sound and Music Computing" that was published in Applied Sciences

Download or read book Acoustics of Ducts and Mufflers written by M. L. Munjal and published by John Wiley & Sons. This book was released on 2014-02-04 with total page 379 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fully updated second edition of the premier reference book on muffler and lined duct acoustical performance Engine exhaust noise pollutes the street environment and ventilation fan noise enters dwellings along with fresh air. People have become conscious of their working environment. Governments of most countries have responded to popular demand with mandatory restrictions on sound emitted by automotive engines, and a thorough knowledge of acoustics of ducts and mufflers is needed for the design of efficient muffler configurations. This fully updated Second Edition of Acoustics of Ducts and Mufflers deals with propagation, reflection and dissipation/absorption of sound along ducts/pipes/tubes, area discontinuities, perforated elements and absorptive linings that constitute the present-day mufflers and silencers designed to control noise of exhaust and intake systems of automotive engines, diesel-generator sets, compressors and HVAC systems. It includes equations, figures, tables, references, and solved examples and unsolved exercises with answers, so it can be used as a text book as well as a reference book. It also offers a complete presentation and analysis of the major topics in sound suppression and noise control for the analysis and design of acoustical mufflers, air conditioning and ventilation duct work. Both the fundamentals and the latest technology are discussed, with an emphasis on applications. Deals with reactive mufflers, dissipative silencers, the frequency-domain approach, and the time-domain approach. Fully updated second edition of the premier reference book on muffler and lined duct acoustical performance, in one complete volume Presents original new research on topics including baffle silencers and louvers, 3D analytical techniques, and flow-acoustic analysis of multiply-connected perforated-element mufflers Includes a general design procedure to help muffler designers in the automotive industry, exhaust noise being a major component of automobile and traffic noise pollution Written by an expert with four decades’ experience in teaching to graduate students, publishing extensively in reputed international journals, and consulting with industry for noise control as well as designing for quietness

Download or read book Uncertainty Management for Robust Industrial Design in Aeronautics written by Charles Hirsch and published by Springer. This book was released on 2018-07-21 with total page 819 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book covers cutting-edge findings related to uncertainty quantification and optimization under uncertainties (i.e. robust and reliable optimization), with a special emphasis on aeronautics and turbomachinery, although not limited to these fields. It describes new methods for uncertainty quantification, such as non-intrusive polynomial chaos, collocation methods, perturbation methods, as well as adjoint based and multi-level Monte Carlo methods. It includes methods for characterization of most influential uncertainties, as well as formulations for robust and reliable design optimization. A distinctive element of the book is the unique collection of test cases with prescribed uncertainties, which are representative of the current engineering practice of the industrial consortium partners involved in UMRIDA, a level 1 collaborative project within the European Commission's Seventh Framework Programme (FP7). All developed methods are benchmarked against these industrial challenges. Moreover, the book includes a section dedicated to Best Practice Guidelines for uncertainty quantification and robust design optimization, summarizing the findings obtained by the consortium members within the UMRIDA project. All in all, the book offers a authoritative guide to cutting-edge methodologies for uncertainty management in engineering design, covers a wide range of applications and discusses new ideas for future research and interdisciplinary collaborations.