211 research outputs found
Signal-Adaptive and Perceptually Optimized Sound Zones with Variable Span Trade-Off Filters
Creating sound zones has been an active research field since the idea was
first proposed. So far, most sound zone control methods rely on either an
optimization of physical metrics such as acoustic contrast and signal
distortion or a mode decomposition of the desired sound field. By using these
types of methods, approximately 15 dB of acoustic contrast between the
reproduced sound field in the target zone and its leakage to other zone(s) has
been reported in practical set-ups, but this is typically not high enough to
satisfy the people inside the zones. In this paper, we propose a sound zone
control method shaping the leakage errors so that they are as inaudible as
possible for a given acoustic contrast. The shaping of the leakage errors is
performed by taking the time-varying input signal characteristics and the human
auditory system into account when the loudspeaker control filters are
calculated. We show how this shaping can be performed using variable span
trade-off filters, and we show theoretically how these filters can be used for
trading signal distortion in the target zone for acoustic contrast. The
proposed method is evaluated based on physical metrics such as acoustic
contrast and perceptual metrics such as STOI. The computational complexity and
processing time of the proposed method for different system set-ups are also
investigated. Lastly, the results of a MUSHRA listening test are reported. The
test results show that the proposed method provides more than 20% perceptual
improvement compared to existing sound zone control methods.Comment: Accepted for publication in IEEE/ACM TRANSACTIONS ON AUDIO, SPEECH,
AND LANGUAGE PROCESSIN
Real-time Microphone Array Processing for Sound-field Analysis and Perceptually Motivated Reproduction
This thesis details real-time implementations of sound-field analysis and perceptually motivated reproduction methods for visualisation and auralisation purposes. For the former, various methods for visualising the relative distribution of sound energy from one point in space are investigated and contrasted; including a novel reformulation of the cross-pattern coherence (CroPaC) algorithm, which integrates a new side-lobe suppression technique. Whereas for auralisation applications, listening tests were conducted to compare ambisonics reproduction with a novel headphone formulation of the directional audio coding (DirAC) method. The results indicate that the side-lobe suppressed CroPaC method offers greater spatial selectivity in reverberant conditions compared with other popular approaches, and that the new DirAC formulation yields higher perceived spatial accuracy when compared to the ambisonics method
Optimizing wide-area sound reproduction using a single subwoofer with dynamic signal decorrelation
A central goal in small room sound reproduction is achieving consistent sound energy distribution across a wide listening area. This is especially difficult at low-frequencies where room-modes result in highly position-dependent listening experiences. While numerous techniques for multiple-degree-of-freedom systems exist and have proven to be highly effective, this work focuses on achieving position-independent low-frequency listening experiences with a single subwoofer. The negative effects due to room-modes and comb-filtering are mitigated by applying a time-varying decorrelation method known as dynamic diffuse signal processing. Results indicate that spatial variance in magnitude response can be significantly reduced, although there is a sharp trade-off between the algorithm’s effectiveness and the resulting perceptual coloration of the audio signal.N/
Sonic interaction with a virtual orchestra of factory machinery
This paper presents an immersive application where users receive sound and
visual feedbacks on their interactions with a virtual environment. In this
application, the users play the part of conductors of an orchestra of factory
machines since each of their actions on interaction devices triggers a pair of
visual and audio responses. Audio stimuli were spatialized around the listener.
The application was exhibited during the 2013 Science and Music day and
designed to be used in a large immersive system with head tracking, shutter
glasses and a 10.2 loudspeaker configuration.Comment: Sonic Interaction for Virtual Environments, Minneapolis : United
States (2014
Perception of Reverberation in Domestic and Automotive Environments
nrpages: 227status: publishe
Proceedings of the EAA Joint Symposium on Auralization and Ambisonics 2014
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.European Acoustics Associatio
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