AAEESS113311 st CCoonnvveenn ttiioonn PPrroo ggrraamm October 20 – 23, 2011 Jacob K. Javits Convention Center, New York, NY, USA The AES has launched a new opportunity to recognize room decay time for bass frequencies. We student members who author technical papers. The Stu - develop the theory for a point active absorber dent Paper Award Competition is based on the preprint immersed in the acoustic source field from a manuscripts accepted for the AES convention. point source. This would apply to normal loud - A number of student-authored papers were nominated. speakers used as either sources or absorbers at The excellent quality of the submissions has made the frequencies below about 300 Hz, where they act selection process both challenging and exhilarating. as points. The result extends the theory of Nel - The award-winning student paper will be honored dur - son and Elliott for a point absorber interacting ing the Convention, and the student-authored manuscript with a plane wave. An extra term occurs that has will be considered for publication in a timely manner for little net effect when averaged over frequency or the Journal of the Audio Engineering Society . distance. In rooms such cancellation occurs due Nominees for the Student Paper Award were required to the varying distances from all the source to meet the following qualifications: images to the absorber. Impulse responses in (a) The paper was accepted for presentation at the several small rooms were measured from a AES 131st Convention. source and an absorber loudspeaker to both a (b) The first author was a student when the work was few listening microphones and a microphone conducted and the manuscript prepared. mounted at the absorber. The efficacy of the (c) The student author’s affiliation listed in the manu - active absorber is assessed and the results are script is an accredited educational institution. enigmatic. (d) The student will deliver the lecture or poster pre - Convention Paper 8458 sentation at the Convention. 9:30 am * * * * * P1-2 Investigations of Room Acoustics with a The Winner of the 131th AES Convention Spherical Microphone Array— Samuel W. Student Paper Award is: Clapp ,1 Anne E. Guthrie ,1,2 Jonas Braasch ,1 Ning Xiang 1 1Rensselear Polytechnic Institute, Troy, NY, USA The Impact of Producers’ Comments and Musicians’ 2 Self-Evaluation on Performance during Arup, New York, NY, USA Recording Sessions— Amandine Pras, Most room acoustic parameters are calculated Catherine Guastavino, McGill University, with data from omni-directional or figure-of-eight Montreal, Quebec, Canada microphones. Using a spherical microphone array Convention Paper 8579 to record room impulse responses can open up To be presented on Sunday, October 23, in Session 25 several new areas of inquiry. It can yield much —Auditory Perception more information about the spatial characteristics of the sound field, including the diffuseness of the sound field and the directions of individual reflec - * * * * * tions. A 16-channel microphone array was designed, built, and tested with both simulations Session P1 Thursday, Oct. 20 and simple, controlled sound events. Room 9:00 am – 11:00 am Room 1E09 impulse responses were then measured in rever - berant rooms used for music from stage and audi - ROOM ACOUSTICS ence positions, and the results were analyzed using beamforming techniques to determine spa - Chair: Peter Mapp , Peter Mapp Associates, tial information about the sound field. Colchester, UK Convention Paper 8459 9:00 am 10:00 am P1-1 New Thoughts on Active Acoustic Absorbers —John Vanderkooy , University of Waterloo, P1-3 Room Acoustics Using a 2.5 Dimensional Waterloo, Ontario, Canada Approach with Damping Included— Patrick Macey , PACSYS Limited, Nottingham, UK This paper continues an earlier exploration of us - ing full-range loudspeakers as both acoustic Cavity modes of a finite bounded region with sources and sinks, in an attempt to reduce the rigid boundaries can be used to compute the ¯ Audio Engineering Society 131st Convention Program, 2011 Fall 1 Technical Progra m steady state harmonic response for point source the needs of each particular sound recording excitation. In cuboid domains this is straightfor - environment. This paper will outline the various ward. In general regions, determining a set of parameters that need to be taken into considera - orthonormal modes is more difficult. Previous tion and explain the basic approach to develop - work showed that for rooms of constant height, ing MATLAB-based software that gives a clear 3-D modes can be computed from the cross sec - and unambiguous display of all the salient char - tion modes, and this used for a fast solution. acteristics needed to achieve a stable and reli - This approach used modal damping. More real - able microphone array, no matter the number of istic damping associated with wall areas could channels involved, or the type of directivity pat - be included using a damped eigenvalue calcula - tern chosen for each microphone. tion of the cross section modes. This is restric - Convention Paper 8461 tive on damping formulations. An alternative non-modal approach, using a trigonometric 9:30 am expansion through the height is proposed. This P2-2 In Situ Measurements of the Concert Grand is still faster than 3-D FEM. Piano— Brett Leonard ,1,2 Grzegorz Sikora ,1 Convention Paper 8460 Martha de Francisco 1,2 1McGill University, Montreal, Quebec, Canada 10:30 am 2Centre for Interdisciplinary Research in Music, P1-4 Accurate Acoustic Modeling of Small Rooms Media and Technology, Montreal, Quebec, —Holger Schmalle ,1 Dirk Noy ,2 Stefan Feistel ,1 Canada Gabriel Hauser ,2 Wolfgang Ahnert ,1 An in situ approach to the acoustical study of the John Storyk 2 grand piano is presented in which the instrument 1AFMG Ahnert Feistel Media Group, Berlin, is coupled with a typical, reflective recording Germany space. By using accurate, tightly controlled auto - 2WSDG Walters-Storyk Design Group, Basal, mated playback of expertly performed material, Switzerland a small number of high-quality transducers are Modeling of sound reinforcement systems and employed to capture more than 1300 spatially room acoustics in large and medium-size distributed data points in the process known as venues has become a standard in the audio in - acoustic space sampling (AcSS). The AcSS dustry. However, acoustic modeling of small measurement task is performed on two pianos in rooms has not yet evolved into a widely accept - two unique recording environments. The data is ed concept, mainly because of the unavailable analyzed using accepted acoustic metrics and tool set. This work introduces a practical and psychoacoustic predictors. It is shown that cer - accurate software-based approach for simulating tain spatial areas containing salient physical and the acoustic properties of studio rooms based on psychoacoustic measures are highly correlated FEM. A detailed case study is presented and recording engineer preference. modeling results are compared with measure - Convention Paper 8462 ments. It is shown that results match within giv - en uncertainties. Also, it is indicated how the 10:00 am simulation software can be enhanced to optimize P2-3 Beyond Surround Sound—Creation, Coding loudspeaker locations and place absorbers and and Reproduction of 3-D Audio Soundtracks diffusers in order to improve the acoustic quality —Jean-Marc Jot ,1 Zoran Fejzo 2 of the space and thus the listening experience. 1DTS, Inc., Scotts Valley, CA, USA Convention Paper 8457 2DTS, Inc., Calabasas, CA, USA Session P2 Thursday, Oct. 20 We propose a flexible and practical end-to-end 9:00 am – 11:00 am Room 1E07 solution for creating, encoding, transmitting, decoding, and reproducing spatial audio sound - RECORDING AND SOUND PRODUCTION tracks. The soundtrack encoding format is com - patible with legacy surround-sound decoders, Chair: Justin Paterson , University of West London, while enabling the representation of a three- London, UK dimensional audio scene, irrespective of the lis - tener’s playback system configuration. It allows for encoding one or more selected audio objects 9:00 am that can be rendered with optimal fidelity and P2-1 Computer Assisted Microphone Array Design interactively in any target spatial audio format (CAMAD)— Michael Williams , Freelance Sound (existing or future). The transmission or storage Recording Engineer and Lecturer, Sounds of data rate and the decoder complexity are scal - Scotland, Le Perreux sur Marne, France able at delivery time. A 3-D audio soundtrack may thus be produced once and transmitted or The basic aim of Microphone Array Design is to broadcast and reproduced as faithfully as possi - create microphone array recording systems with ble on the broadest range of target devices. smooth seamless or “Critically Linked” segment Convention Paper 8463 coverage of the surround sound field. Each con - figuration must take into account the interaction 10:30 am of the many design parameters, with the specific coverage of each segment that is required. The P2-4 The Effects of Multiple Arrivals on the difficulty in the manipulation of these many para - Intelligibility of Reinforced Speech— Timothy meters is one of the major obstacles in develop - J. Ryan ,1 Richard King ,1 Jonas Braasch ,2 ing a wide range of microphone arrays that meet William L. Martens 3 2 Audio Engineering Society 131st Convention Program, 2011 Fall 1McGill University, Montreal, Quebec, Canada It's not talked about often, but almost no two brands of 2Rensselaer Polytechnic University, Troy, NY, USA digital loudspeaker processors use the same filter defini- 3University of Sydney, Sydney, NSW, Australia tions. As a result, there is no such thing as a cross-plat- form, DSP agnostic, optimal crossover setting. This pan- The effects of multiple arrivals on the intelligibility el looks at how to create a precise set of crossover and of speech produced by live-sound reinforcement equalization filters for the best loudspeaker performance systems are examined. The intent is to determine despite so much variability in DSP filter shapes.