Two multi-channel microphone techniques for natural music and sound effects reproduction are experimentally compared. Simultaneous surround sound recordings of several genres of music and ambience are made in concert hall, studio, and outdoors. Trained listeners subjectively evaluate the abilities and tradeoffs of each system to recreate accurate panoramic localization and spatial impression of opera, bluegrass with audience participating, flute quartet, brass quintet, marching bands with surrounding crowd and building echoes, and 360° “Walkabout” azimuth test. Differing speaker layouts for 5.1 and “Panor-Ambiophonic” Surround are shown to satisfy two distinct listening audiences, which are further divided into home, automotive, and PC markets. An approach to recording level-setting, compatible production, and delivery formats are introduced to satisfy these diverse end uses.
Convention Paper 5577

09:30 h
M2 Surround Audio That Lasts: Future-proof Ambisonic Recording and Processing Technique for the Real World – Culann mac Caba, Cuan, Spiddal, Ireland

The evolution of surround audio presents new challenges to recording engineers. While there may be some consensus on best practice for the 5.1 playback format, content compatibility for future formats is increasingly important. This paper describes practical experiences of these issues in a Music Recording context, using Ambisonic technology to achieve excellent spatial realism without changing classic workflow practices. Furthermore, the paper shows how this approach allows for simultaneous mixes to be made for playback scenarios as yet undefined, including possible "with-height" formats.
Convention Paper 5578

10:00 h
M3 Parameterization and Reproduction of Concert Hall Acoustics Measured with a Circular Microphone Array – Edo Hulsebos, Diemer de Vries, Delft University of Technology, Delft, Netherlands

In order to correctly reproduce the acoustic wave field in a hall over a large listening area through a Wave Field Synthesis reproduction system, impulse responses are nowadays measured along arrays of microphone positions. These measurements could be used directly for reproduction if the positions of the microphones in the hall correspond to the positions of the loudspeakers in the reproduction array (holophony). However, this approach is not very flexible and the amount of data and real-time processing required is extremely large. Therefore a relatively small circular microphone array is used instead and the measured data are spatially and temporarily parameterized to obtain more playback flexibility and to reduce the amount of data and real-time processing without sacrificing perceptual quality and listening area size. In this paper these parameterization techniques are discussed and applied to circular array measurements done in the Amsterdam Concertgebouw. The main application of all this is future high quality audio with realistic room acoustic reproduction over a large listening area.
Convention Paper 5579

10:30 h
M4 Perception-Based Design of Virtual Rooms for Sound Reproduction – Renato Pellegrini, Ulrich Horbach, Studer Prof. Audio AG, Regensdorf, Switzerland

A perception-based parametric model to design auditory virtual environments using a limited small number of reflections and a model of diffusion was used to simulate virtual environments in a binaural (2 channels) and a wave field synthesis (more than 28 channels) reproduction system. Different perceptual parameters such as the room-size, the distance to the source(s), the positioning of the sources(s), the apparent source width, and more can be adjusted by simple control parameters. Rather than recreating a real room as accurately as possible, the main goal was to design nice-sounding environments for speech and music-reproduction. The achieved quality of the resulting virtual rooms is compared to the quality of measured real rooms.
Convention Paper 5580

11:00 h
M5 Natural Reproduction of Music and Environmental Sounds – Nick Zacharov¹, Matti Fredriksson² - ¹Nokia Research Center, Tampere, Finland; ²Sibelius Academy, Helsinki, Finland

This study considers the spatial sound reproduction requirements to reproduce environmental sounds in a subjectively natural manner. Recordings for this work were performed in six different sound environments, including different styles of musical performances and also other environmental sounds. Both Soundfield microphone and binaural techniques were used for these recordings. The recordings were processed for reproduction over seven different multichannel sound systems in a standard listening room, ranging from stereo to periphonic reproduction. A formal listening test was arranged employing 14 listeners to evaluate the naturalness of reproduction through these systems in a standard listening room. The results indicate that large number of reproduction channels is not always necessary to reproduce subjectively natural sound. This paper presents the results of the study.
Convention Paper 5581

11:30 h
M6 Subjective Experiments on the Effects of Combining Spatialized Audio and 2D Video Projection in Audio-Visual Systems – Werner de Bruijn, Marinus Boone, Delft University of Technology, Delft, Netherlands

When in an audio-visual system spatialized audio reproduction is combined with 2D video projection this has effects on the resulting audio-visual experience of observers. Specifically, a mismatch between perceived auditory and visual source directions may occur for observers that are not in the ideal viewpoint of the video projection. Subjective experiments were carried out to investigate the effects in the context of a life-size video conferencing system. Results show that the non-identical perspectives of the audio and video reproductions indeed have a significant influence on subjects' evaluation of the total system. Solutions are proposed to improve the matching of the audio and video scenes for a large listening area.
Convention Paper 5582

12:00 h
M7 Making Surround Audio Considering Image Proximity Effect – Andrzej Czyzewski, Bozena Kostek, Piotr Odya - Technical University of Gdansk, Gdansk, Poland

The problem of influencing surround sound perception by video content was addressed employing subjective testing procedures in which experts listened to the sound with- and without video image presence and provided their answers. Results of experiments demonstrated in which cases and how video may affect the localization of virtual sound sources. The obtained data were then analyzed by means of modern techniques of intelligent data exploration and knowledge discovery allowing finding some hidden relations between semantic descriptors of subjective impressions. Finally, basing on the results of data analysis a set of rules concerning mastering of multichannel audio to accompany various types of video content were derived. Some results of this study will be presented and discussed in the paper.
Convention Paper 5583

12:30 h
M8 Training of Listeners for the Evaluation of Spatial Sound Reproduction – Tobias Neher, Tim Brookes, Francis Rumsey, University Of Surrey, Guildford, UK

This paper presents some preliminary results from an ongoing study into methods for the training of listeners in subjective evaluation of spatial sound reproduction. Exemplary stimuli were created illustrating two spatial attributes: individual source width and source distance. Changes in each of the two attributes were highly controlled in an attempt to allow uni-dimensional variation of their perceptual effects. The stimuli were validated with the help of an experienced listening panel and then used to instruct naïve listeners. By comparing the listeners' performances at ranking a number of stimuli before and after the training sessions the effectiveness of the adopted method was quantified.
Convention Paper 5584

13:00 h
M9 The Active Listening Room - A Subjective Analysis – Amber Naqvi¹, Francis Rumsey² - ¹University of Surrey, London, UK; ²University of Surrey, Guildford, UK

This paper presents the results of computer simulation and the actual room measurements of reflection patterns from the active reflector arrangement in a reference listening room which will be used to create artificial reflections in a five speaker, surround listening configuration. This formulates the third and final phase of design experiments relating to the panel arrangement to create a perceptually reflection free zone involving the analysis of computer modeling and room measurement results. Results of a pilot listening test using a well defined stimuli with artificial reflections generated by the DML loudspeaker arrangements are also presented.
Convention Paper 5585