Sound signal processing for a virtual room

EURASIP Journal on Advances in Signal Processing, 2007

A real-time audio rendering system is introduced which combines a full room-specific simulation, dynamic crosstalk cancellation, and multitrack binaural synthesis for virtual acoustical imaging. The system is applicable for any room shape (normal, long, flat, coupled), independent of the a priori assumption of a diffuse sound field. This provides the possibility of simulating indoor or outdoor spatially distributed, freely movable sources and a moving listener in virtual environments. In addition to that, near-tohead sources can be simulated by using measured near-field HRTFs. The reproduction component consists of a headphone-free reproduction by dynamic crosstalk cancellation. The focus of the project is mainly on the integration and interaction of all involved subsystems. It is demonstrated that the system is capable of real-time room simulation and reproduction and, thus, can be used as a reliable platform for further research on VR applications.

We present an audio-visual Virtual Reality display system for simulated sound fields. This system combines the simulation of acoustics inside closed rooms, different approaches for visualizing the sound propagation as well as the auralization of the resulting signals. The room acoustic simulation is performed by use of a particle tracing algorithm, the Phonon Tracing, applied at middle and high frequency range, combined with a wave-based approach (FEM solver) utilized for low frequencies. For a realistic representation of the simulation results we use a stereoscopic back projection system for rendering as well as a professional sound system for audio reproduction. For auralization purposes we developed a soundfield synthesis approach for accurate control of the loudspeaker system.

1999

Virtual home theatre systems provide an efficient means of multichannel sound reproduction with two loudspeakers. Six commercial and academically developed systems have been collected and subjectively evaluated under controlled conditions against discrete 5-channel reproduction. Tests have been carried out in two test rooms. The experimental design and the detailed analysis of results are presented in this paper. 1 It should be noted that all virtual surround or virtual home theater concepts discussed in this experiment refer to 2-loudspeaker reproduction of 5.1 audio material in such a way that at least the surround (and possibly also the center, left and right) audio channels are processed virtually. 2 Written petition with signatures radiating from circles to conceal the order of writing-The Oxford English dictionary.

Ear & Hearing, 2020

To assess perception with and performance of modern and future hearing devices with advanced adaptive signal processing capabilities, novel evaluation methods are required that go beyond already established methods. These novel methods will simulate to a certain extent the complexity and variability of acoustic conditions and acoustic communication styles in real life. This article discusses the current state and the perspectives of virtual reality technology use in the lab for designing complex audiovisual communication environments for hearing assessment and hearing device design and evaluation. In an effort to increase the ecological validity of lab experiments, that is, to increase the degree to which lab data reflect real-life hearing-related function, and to support the development of improved hearing-related procedures and interventions, this virtual reality lab marks a transition from conventional (audio-only) lab experiments to the field. The first part of the article intro...

2004

Procedia Technology, 2012

This paper focuses on the behavior of sound on combining: "Navigation, 3D objects and 3D sound", in different virtual worlds, which are displayed on multiple screens. Our project allows building different virtual environment using one or more screens, with a full navigation system, four ways of manipulating using keyboard, head tracker, remote control and input files with different predefined tours. Furthermore, with this project we can also build a Wheatstone-type stereoscope. We have implemented three virtual worlds for the different environments: The first one shows a collection of anaglyphic photographs; the second one is a collection of photographs of roman art; the third one is a computing center.

Proc. of Int'l Conf. Auditory …, 1998

This paper describes multi-speaker display systems for immersive auditory environments, collaborative projects, realistic acoustic modeling, and live musical performance. Two projects are described. The sound sub-system of the Princeton Display Wall project, and the NBody musical instrument body radiation response project. The Display Wall is an 18' x 8' rear-projection screen, illuminated by 8 high-resolution video projectors. Each projector is driven by a 4-way symmetric-multi-processor PC. The audio sub-system of this project involves 26 loudspeakers and server PCs to drive the speakers in real time from soundfile playback, audio effects applied to incoming audio streams, and parametric sound synthesis. The NBody project involves collecting and using directional impulse responses from a variety of stringed musical instruments. Various signal processing techniques were used to investigate, factor, store, and implement the collected impulse responses. A software workbench was created which allows virtual microphones to be placed around a virtual instrument, and then allows signals to be processed through the resulting derived transfer functions. Multi-speaker display devices and software programs were constructed which allow real-time application of of the filter functions to arbitrary sound sources. This paper also discusses the relation of spherical display systems to conventional systems in terms of spatial audio and sound-field reconstruction, with the conclusion that most conventional techniques can be used for spherical display systems as well.

2011

Authenticity of the simulation of room acoustics is evaluated by comparing auralizations with real recordings. Impulse responses are recorded in two concert halls with 34 loudspeakers positioned on the stage in the shape of an orchestra and a 3D microphone probe for spatial reproduction. The acoustics of the same concert halls are simulated with acoustics modeling software. B-format impulse responses are calculated by using the identical source and receiver positions as in the real halls.

1986

A real-time virtual audio reality model has been created. The system includes model-based soundsynthesizers, geometrical room acoustics modeling, binaural auralization for headphone or loudspeakerlistening, and hiqh-quality animation. This paper discusses the following subsystems of thedesigned environment: The implementation of the audio processing soft- and hardware, and the designof a dedicated multiprocessor DSP hardware platform. The design goal of the overall

2003