Author: Michael Vorländer
Publisher: Springer Science & Business Media
ISBN: 9783540488309
Size: 12.80 MB
Format: PDF, Mobi
View: 87

This is the first focused and detailed textbook on acoustic virtual reality. Auralization is the creation of audible acoustic sceneries from computer-generated data. The term "auralization" is to be understood as being analogue to the well-known technique of "visualization". In visual illustration of scenes, data or any other meaningful information, in movie animation and in computer graphics, we describe the process of "making visible" as visualization. In acoustics, auralization is taking place when acoustic effects, primary sound signals or means of sound reinforcement or sound transmission, are processed to be presented by using electro-acoustic equipment. This book is organized as a comprehensive collection of basics, methodology and strategies of acoustic simulation and auralization.

Partitioned Convolution Algorithms For Real Time Auralization

Author: Frank Wefers
Publisher: Logos Verlag Berlin GmbH
ISBN: 9783832539436
Size: 12.29 MB
Format: PDF, ePub, Mobi
View: 63

This work discusses methods for efficient audio processing with finite impulse response (FIR) filters. Such filters are widely used for high-quality acoustic signal processing, e.g. for headphone or loudspeaker equalization, in binaural synthesis, in spatial sound reproduction techniques and for the auralization of reverberant environments. This work focuses on real-time applications, where the audio processing is subject to minimal delays (latencies). Different fast convolution concepts (transform-based, interpolation-based and number-theoretic), which are used to implement FIR filters efficiently, are examined regarding their applicability in real-time. These fast, elementary techniques can be further improved by the concept of partitioned convolution. This work introduces a classification and a general framework for partitioned convolution algorithms and analyzes the algorithmic classes which are relevant for real-time filtering: Elementary concepts which do not partition the filter impulse response (e.g. regular Overlap-Add and Overlap-Save convolution) and advanced techniques, which partition filters uniformly and non-uniformly. The algorithms are thereby regarded in their analytic complexity, their performance on target hardware, the optimal choice of parameters, assemblies of multiple filters, multi-channel processing and the exchange of filter impulse responses without audible artifacts. Suitable convolution techniques are identified for different types of audio applications, ranging from resource-aware auralizations on mobile devices to extensive room acoustics audio rendering using dedicated multi-processor systems.

Physically Based Real Time Auralization Of Interactive Virtual Environments

Author: Dirk Schröder
Publisher: Logos Verlag Berlin GmbH
ISBN: 9783832530310
Size: 12.23 MB
Format: PDF, Kindle
View: 88

Analogous to visualization, the auralization of virtual environments describes the simulation of sound propagation inside enclosures where methods of Geometrical Acoustics are mostly applied for a high-quality synthesis of aural stimuli that go along with a certain realistic behavior. In the course of this thesis, the design and implementation of the real-time room acoustics simulation software RAVEN will be described, which is a vital part of the implemented 3D sound-rendering system of RWTH Aachen University's immersive Virtual Reality system. RAVEN relies on present-day knowledge of room acoustical simulation techniques and enables a physically accurate auralization of sound propagation in complex environments including important wave effects such as sound scattering, airborne sound insulation between rooms and sound diffraction. Despite this realistic sound field rendering, not only spatially distributed and freely movable sound sources and receivers are supported at runtime but also modifications and manipulations of the environment itself. All major features are evaluated by investigating both the overall accuracy of the room acoustics simulation and the performance of implemented algorithms, and possibilities for further simulation optimizations are identified by assessing empirical studies of subjects operating in immersive environments

Proceedings Of The Eaa Joint Symposium On Auralization And Ambisonics 2014

Author: Weinzierl, Stefan
Publisher: Universitätsverlag der TU Berlin
ISBN: 9783798327047
Size: 14.27 MB
Format: PDF
View: 52

In consideration of the remarkable intensity of research in the field of Virtual Acoustics, including different areas such as sound field analysis and synthesis, spatial audio technologies, and room acoustical modeling and auralization, it seemed about time to organize a second international symposium following the model of the first EAA Auralization Symposium initiated in 2009 by the acoustics group of the former Helsinki University of Technology (now Aalto University). Additionally, research communities which are focused on different approaches to sound field synthesis such as Ambisonics or Wave Field Synthesis have, in the meantime, moved closer together by using increasingly consistent theoretical frameworks. Finally, the quality of virtual acoustic environments is often considered as a result of all processing stages mentioned above, increasing the need for discussions on consistent strategies for evaluation. Thus, it seemed appropriate to integrate two of the most relevant communities, i.e. to combine the 2nd International Auralization Symposium with the 5th International Symposium on Ambisonics and Spherical Acoustics. The Symposia on Ambisonics, initiated in 2009 by the Institute of Electronic Music and Acoustics of the University of Music and Performing Arts in Graz, were traditionally dedicated to problems of spherical sound field analysis and re-synthesis, strategies for the exchange of ambisonics-encoded audio material, and – more than other conferences in this area – the artistic application of spatial audio systems. This publication contains the official conference proceedings. It includes 29 manuscripts which have passed a 3-stage peer-review with a board of about 70 international reviewers involved in the process. Each contribution has already been published individually with a unique DOI on the DepositOnce digital repository of TU Berlin. Some conference contributions have been recommended for resubmission to Acta Acustica united with Acustica, to possibly appear in a Special Issue on Virtual Acoustics in late 2014. These are not published in this collection.

Handbook Of Signal Processing In Acoustics

Author: David Havelock
Publisher: Springer Science & Business Media
ISBN: 9780387776989
Size: 12.29 MB
Format: PDF, ePub
View: 64

The Handbook of Signal Processing in Acoustics brings together a wide range of perspectives from over 100 authors to reveal the interdisciplinary nature of the subject. It brings the key issues from both acoustics and signal processing into perspective and is a unique resource for experts and practitioners alike to find new ideas and techniques within the diversity of signal processing in acoustics.