AES Los Angeles 2014
Engineering Brief Details
EB1 - eBriefs—Poster Session 1
Thursday, October 9, 11:00 am — 12:30 pm (S-Foyer 1)
EB1-1 Analysis of Sound Field Generated by Line Arrays with Waveguides—Xuelei Feng, Nanjing University - Nanjing, Jiangsu, China; Yong Shen, Nanjing University - Nanjing, Jiangsu Province, China; Simiao Chen; Ye Zhao
Considering that a loudspeaker line array results from assembly of separate loudspeaker enclosures, it is important to take the gaps between enclosures into account and the line array is considered as a collection of several line sources of certain height. Particularly at high frequency, since the waveguides are used as the array element to achieve the line sources, the sound field generated by the arrays of waveguides is analyzed. The results are compared with those described in previous works that assumed that the array elements were perfect line sources.
Engineering Brief 156 (Download now)
EB1-2 Active Noise, Acoustic Echo, and Audio Ducking Using TMSC5535 eZdsp USB Stick Development Kit—Name Withheld, Removed at the request of the presenter.
Audio Ducking, Active Noise and Acoustic Echo Cancellation using TMS320C5535 eZdsp USB Stick Development Kit is an application system designed for live audio broadcasting and recording purposes. This application system initializes and executes adaptive audio and acoustic signal processing algorithms using a high performance and low power DSP TMS320C5535. In this study three sub-systems are discussed in brief and finally system setup and implementation is analyzed.
Engineering Brief 157 (Download now)
EB1-3 Loudspeaker Electrical Impedance Measurements Methods: A Brief Review—Daniele Ponteggia, Audiomatica Srl - Firenze (FI), Italy
There are several possible methods to measure the loudspeaker driver electrical impedance. Those methods have followed the development of measurement instruments starting from the era of the simple needle voltmeters to the PC based instruments widely available today. This paper will go through the theory and practice of impedance measurements with a series of examples where the pros and cons of each method are highlighted using real measurements. Effect of current sensor choice, noise, vibrations and test level will be discussed in detail.
Engineering Brief 158 (Download now)
EB1-4 Sound Field Intensity Measurements and Visualization around the Human Head Model—Bozena Kostek, Gdansk University of Technology - Gdansk, Poland; Audio Acoustics Lab.; Adam Kurowski, Technical University of Gdansk - Gdansk, Poland; Piotr Kryger, Gdansk University of Technology - Gdansk, Poland; Andrzej Czyzewski, Gdansk University of Technology - Gdansk, Poland
The main goal of this research study was to measure and visualize sound field in the presence and without presence of the human head model. Measurements were performed in the anechoic chamber at 5 cm grid. Experimental setup consisted of a multitone generator, two loudspeakers, human head model, intensimetric probe, the Cartesian robot applied for precise positioning of the acoustic sensor, and an analyzer. Based on the collected data sound field visualization was created in the form of colored maps and arrows illustrating pressure and the intensity vector at a given point in the presence of the artificial head, without this obstacle and the difference resulted from the mentioned conditions. A thorough analysis of the results obtained and conclusions followed.
Engineering Brief 160 (Download now)
EB1-5 Stereo Aligned Saturation—Quintino G. Sardo, SKnote - SK Cooperativa - S. G. La Punta (CT), Italy; Angelo Mangano, SKnote - SK Cooperativa - La Punta (CT), Italy
All analog devices provide a finite dynamic range. Saturation occurs when available headroom ceiling is reached. Often, saturation is a desired effect to provide punch, brightness or changes in timbre, but stereo image is compromised because stereo saturation cannot be matched. Tests and methods for stereo aligned saturation are analyzed and described.
Engineering Brief 174 (Download now)
EB2 - eBriefs—Poster Session 2
Friday, October 10, 10:30 am — 12:00 pm (S-Foyer 1)
EB2-1 Android Framework Implementation of 3D Audio with Range Control—Phyo Ko Ko, Nanyang Technological University - Singapore; Kaushik Sunder, Nanyang Technological University - Singapore, Singapore; Woon-Seng Gan, Nanyang Technological University - Singapore, Singapore
Due to the rapid improvement in processing power of mobile devices, real-time 3D audio rendering is becoming a reality on these devices. Using 3D audio rendering, many interesting applications, such as teleconferencing and immersive gaming can be developed. In this paper, an Android framework is developed for rendering 3D audio in real-time with additional range control. Range-dependent head related transfer functions (HRTFs) are used in order to render the spatial audio. Distance dependent HRTFs are extremely tedious to be measured since these measurements have to be carried out for several distances in the near-field. In this work, the range-dependent HRTFs used by the Android framework are experimentally measured in the horizontal plane and made available online for the researchers to use. This 3D audio framework will serve as a useful platform to deliver new audio processing applications, such as teleconferencing over headphones, personalized hearing in gaming and virtual reality etc.
Engineering Brief 161 (Download now)
EB2-2 Flexible Audio Rendering for Arbitrary Input and Output Layouts—Hyunjoo Chung, Samsung Electronics Co. Ltd. - Suwon, Korea; Sang Bae Chon, Samsung Electronics Co. Ltd. - Suwon, Korea; Sunmin Kim, Samsung Electronics Co. Ltd. - Suwon, Korea
This engineering brief introduces a rendering method compatible with various input audio formats and output reproduction layouts. By using audio scene analysis, N-channel audio input signals are converted to channel-independent spatial parameters then sound fields are rendered based on the M-channel output loudspeaker layout with maintaining spatial information of original audio formats. Therefore, proposed method enabled N-to-M flexible audio rendering with immersive sound perception.
Engineering Brief 163 (Download now)
EB2-3 A Touchpad-Based Method for Inducing Attentional Tunneling—Durand R. Begault, NASA Ames Research Center - Moffett Field, CA, USA; Bonny R. Christopher, San Jose State University Research Foundation, NASA Ames Research Center - Moffett Field, CA, USA; Charlotte Zeamer, NASA Ames Research Center - Moffett Field, CA, USA; Mark R. Anderson, NASA Ames Research Center - Moffett Field, CA, USA; Kirstianna Burns, City College of San Francisco - San Francisco, CA, USA
Attentional tunneling is a recognized problem for aviation safety in the flight deck. A prototype system (touchpad and associated application and experimental software) was developed and evaluated for its success in inducing attentional tunneling in a reliable and predictable manner in training and experimental contexts. An experiment with ten participants using the system examined baseline performance for visual memory of a color or number sequence, simultaneous with performing a competing auditory detection task. Spatial auditory separation of the auditory stimuli was also evaluated. Data are provided for various aspects of touchpad entry (accuracy, speed) as well as hit and false alarm rates for the auditory task. The results will help determine means of inducing attentional tunneling in more complex flight simulator experiments and for developing an inexpensive prototype for pilots to measure cognitive fixation and develop mitigation strategies.
Engineering Brief 164 (Download now)
EB2-4 The Open Multitrack Testbed—Brecht De Man, Queen Mary University of London - London, UK; Mariano Mora-Mcginity, Queen Mary University of London - London, UK; György Fazekas, Queen Mary University of London - London, UK; Joshua D. Reiss, Queen Mary University of London - London, UK
We introduce the Open Multitrack Testbed, an online repository of multitrack audio, mixes or processed versions thereof, and corresponding mix settings or process parameters such as DAW files. Multitrack audio is a much sought after resource for audio researchers, students, and content producers, and while some online resources exist, few are large and reusable and none allow querying audio fulfilling specific criteria. The test bed we present contains a semantic database of metadata corresponding with the songs and individual tracks, enabling users to retrieve all pop songs featuring an accordion, or all tracks recorded in reverberant spaces. The open character is made possible by requiring the contributions, mainly from educational institutions and individuals, to have a Creative Commons license.
Engineering Brief 165 (Download now)
EB2-5 Maintenance Considerations in Higher Education Facilities—Daniel Gonko, Western Carolina University - Cullowhee, NC, USA
Running and maintaining a recording studio in a higher education environment poses various benefits and challenges that are not often encountered in commercial facilities. This presentation will examine the pros and cons of working in such a facility, including availability, funding considerations, and training needs. The Center for Applied Technology and Commercial and Electronic Music degree program at Western Carolina University will be utilized as a case study.
Engineering Brief 166 (Download now)
EB3 - eBriefs—Papers Session 1
Friday, October 10, 5:00 pm — 6:15 pm (Room 308 AB)
Chair:
Christoph M. Musialik, Sennheiser Audio Labs - Waldshut-Tiengen, Germany
EB3-1 "It Has to Work With the Picture": Audio Education for Film and Media Students—Ufuk Onen, Bilkent University - Ankara, Turkey
Audio education for students who major in filmmaking, video production, visual media practice, or visual communication design in universities' bachelor-degree programs usually starts with creating and improving awareness for sound both in general and, also, in relation to visual media as well. In addition to that, since these students utilize recording and mixing only as a part of their professional practice, not as their main field of specialty, teaching the technical concepts and aesthetics to them requires making use of different content and approach than to those who intend to become audio specialists. This paper discusses these issues by using COMD 361 Sound Design course at Bilkent University, Department of Communication and Design, as a case study.
Engineering Brief 167 (Download now)
EB3-2 Film Production Sound in Secondary Markets—The Value of Networking—Tom Hauser, Hooz Audio - Winston-Salem, NC, USA
I came back home to North Carolina after a negative experience interning in Nashville and eventually navigated my way into sound for picture in corporate and commercial work. I have built my network over several years, gone to grad school for film scoring, moved away from the slightly more competitive area of Raleigh, and now have a small 5.1 mixing studio in Winston-Salem, NC. I want to highlight some of the things a young person needs to know to get work as a new comer among veterans where ever they go, emphasize continual skill development beyond school, the value of personal relationships, and navigating the ups and downs of being a freelancer.
Engineering Brief 168 (Download now)
EB3-3 "Object" Panning for Film: Challenges and Solutions—Ben Loftis, Harrison Consoles - Nashville, TN, USA
Object-based panning allows film mixers to break free of the limits imposed by traditional surround formats. Harrison Consoles has developed software panning that allows sounds to be treated as objects in a 3D space that can then be rendered in various surround formats. This enables users to mix in immersive sound formats and transition to traditional surround formats without having to start a new mix; it was most recently implemented at Sony Pictures for the mix of The Amazing Spider-Man 2. Explained in this paper are the obstacles that we faced, and how we overcame them, making technologies such as Dolby Atmos and Barco Auro3D part of the original mix rather than an afterthought.
Engineering Brief 169 (Download now)
EB3-4 Orchestral Recording and Live Webcasting at McGill University—Alejandro Aspinwall, McGill University - Montreal, QC, Canada; Centre for Interdisciplinary Research in Music Media and Technology (CIRMMT) - Montreal, Quebec, Canada
Recording and broadcasting live audio and video of a large student orchestra performance can be a tremendous challenge but can also be a great educational experience when organized properly. The most important aspects to succeed in this task are assembling a team of students with the adequate technical skills to resolve potential problems and putting together an efficient system that can handle potential problems such as power outages or digital audio workstation failure. This kind of event prepares the students for real life scenarios where they will encounter similar workflows and will be able to spot and prevent technical flaws that could compromise the success of future events. Finally, having a group of students with assigned responsibilities will improve their teamwork skills and allow them to communicate with peers outside their area of expertise.
Engineering Brief 170 (Download now)
EB3-5 Stereo Bluetooth and Low Latency Applications—Jonny McClintock, CSR - Belfast, Northern Ireland, UK
The A2DP Bluetooth protocol is used to transport stereo audio over a non-synchronous packetized structure. Using a frame-based codec, i.e., SBC or AAC, results in system latencies between 150 and 800 milliseconds with wide drifts up to +/– 200ms. A2DP can be used for music but because of the problems associated with the frame-based codecs, Bluetooth is not suitable for audio for video or gaming applications. The aptX codec offers an alternative. It uses a fundamentally different coding architecture and is sample-based
delivering a system latency of 40ms with minimal drift, i.e., +/– 1 ms. With the use of aptX, Bluetooth can now be used to wireless connect TV’s to soundbars, gaming consoles to headsets, and PC’s to speakers.
Engineering Brief 171 (Download now)
EB4 - eBriefs—Papers Session 2
Saturday, October 11, 11:30 am — 1:00 pm (Room 309)
Chair:
Eric M. Benjamin, Surround Research - Pacifica, CA, USA
EB4-1 SoundWire: A New MIPI Standard Audio Interface—Pierre-Louis Bossart, Intel Corporation - Austin, TX; Juha Backman, Microsoft - Espoo, Finland; Jens Kristian Poulsen, BlackBerry - Waterloo, ON, Canada
This paper presents the key features of the upcoming SoundWire hardware interface and protocol. SoundWire is a robust, scalable, low complexity, low power, low latency, two-pin (clock and data) multi-drop bus that allows for the transfer of multiple audio streams and embedded control/commands. SoundWire provides synchronization capabilities and supports both PCM and PDM, multichannel data, isochronous and asynchronous modes. The development of this interface has generated a lot of interest and contributions from providers of audio peripherals (microphones, amplifiers & audio codecs), silicon vendors and OEMs. It will become a ratified standard by MIPI (Mobile Industry Processor Interface consortium) at the end of 2014. The first products should appear in 2015 and enable new usage models or design choices for audio applications.
Engineering Brief 172 (Download now)
EB4-2 Performance and Response: A Framework to Discuss the Quality of Audio Systems—Ron Bakker, Yamaha Music Europe - Vianen, Netherlands; Masahiro Ikeda, Yamaha Corporation - Hamamatsu, Shizuoka, Japan; Sungyoung Kim, Rochester Institute of Technology - Rochester, NY, USA
Recently we have designed a new networked digital audio system that is far more flexible yet complicated than before. A main design parameter was sound quality, focusing on cognitive judgment as well as physical quality since they both significantly influence the final sound quality evaluation. To adopt a human centric based approach for the design of a flexible networked digital audio system, the authors redefine the concept of sound quality assessment that classifies a system’s overall quality into two attributes: a physical part as performance and a cognitive part as response.
Engineering Brief 173 (Download now)
EB4-3 Analog Mixer Digitally Controlled via Plugin—Vasin Limsukhawat, Max Sound Contour - Denver, CO, USA; University of Colorado at Denver
The purpose of this project is to turn an old analog mixer to be more controllable which enhances the workflow to be more efficient. It consists of two major components: hardware and software. A microcontroller has been used to control the motorized potentiometer as well as transfer all the data from the mixer to the plugin or vice versa. This provides an ability to control the mixer via the AU plugin or manually adjust as well as save and recall presets.
Engineering Brief 175 (Download now)
EB4-4 Performance of the Microphone-Preamp Interface—Eric M. Benjamin, Surround Research - Pacifica, CA, USA; Andrew Kimpel, AURALab - San Francisco, CA, USA
The microphone/preamp interface is very important but not as well understood as its importance would suggest. The signal level between the microphone and the preamp is at the lowest level it will ever be. Furthermore, any degradation or loss of quality can’t be restored by later processing. The microphone, microphone cable, and preamplifier are made by different companies. The power for the microphone comes from the preamplifier. To optimally design the preamplifier it would be desirable to know the signal levels and the output impedance of the microphone. Also, the output impedance of the microphone affects the intrusion of external electrical noise into the system. A survey and study of the interface yields new insights into system performance.
Engineering Brief 176 (Download now)
EB4-5 Removal of Partially Correlated Noise to Improve Signal to Noise Ratio—A Theoretical Study—Simon Busbridge, University of Brighton - Brighton, UK; Chris Garrett, University of Brighton - Brighton, UK
Time correlation and decorrelation are well established tools to improve the signal to noise ratio of a system, yet they are often poorly understood. When several unwanted signals are correlated they are much easier to remove from uncorrelated wanted signals than vice versa, where a much poorer improvement is possible. A case in point is the removal of wind noise from microphone signals. The situation is further compounded when one or other of the signals is only partially correlated or different spectral content is differently correlated. This paper looks at the theoretical improvement in signal to noise ratio when either the signal or the noise are correlated to different degrees. Application to real signals and noise is discussed.
Engineering Brief 177 (Download now)
EB4-6 Dynamic Audio Imaging In Radial Virtual Reality Environments—Mark Blewett, University of Illinois at Chicago - Chicago, IL, USA; James Pinkl, University of Illinois at Chicago - Chicago, IL, USA; Bryan Dalle Molle, University of Illinois at Chicago - Chicago, IL, USA
The CAVE2 is a large scale, 320 degree, 3D / 2D
virtual reality environment featuring motion capture technology and located in the Electronic Visualization Laboratory at the University of Illinois at Chicago. The environment includes a 20.2 channel sound system controlled by a SuperCollider based audio server that is, in turn, controlled via the proprietary Omicron SoundAPI. Audio imaging for the system had operated with the assumption that the listener was stationary in the center of the CAVE2 and spatial extent was not
dynamically altered. Our team added functionality to maintain audio imaging, including source position and width, as a tracked user and sound object move relative to one another within the environment.
Engineering Brief 162 (Download now)
EB5 - eBriefs—Papers Session 3
Saturday, October 11, 5:00 pm — 6:15 pm (Room 309)
Chair:
Ville Pulkki, Aalto University - Espoo, Finland; Technical University of Denmark - Denmark
EB5-1 Comparison and Contrast of Reverberation Measurements in Grace Cathedral San Francisco—Wieslaw Woszczyk, McGill University - Montreal, QC, Canada; Durand R. Begault, NASA Ames Research Center - Moffett Field, CA, USA; Amanda G. Higbie, Oxford Acoustics - Oxford, MS, USA
In 2001 and 2013 the authors made separate and contrasting acoustical measurements of reverberation within Grace Cathedral, a gothic-style church located in San Francisco notable for its long reverberation time and immersive sound quality for musical performance. Both measurements used different, non-standard methods for generating and
capturing the reverberant sound field. This paper explores the synergy between both sets of measurements for both recording applications and for understanding spatial hearing in large spaces. Applications include manipulation of the perceived size of relatively smaller enclosures having multiple coupled spaces and for improving the long term habitability of space stations, lunar outposts, or other confined spaces.
Engineering Brief 178 (Download now)
EB5-2 The Design of Dolby ATMOS Post Production Theaters—Andrew Munro, Munro Acoustics, Dynaudio Acoustics - London, UK; APRS director
The introduction of Dolby ATMOS has raised several questions concerning the optimum design of the room acoustics for smaller dubbing theaters where the number of speakers and the associated hardware has some bearing on the room as a whole. It is also apparent that compact speaker systems and a flexible approach to installation opens the scope for multi-channel sound installations. The author compares several installation and also compares these with an alternative approach using the IOSONO system.
Engineering Brief 179 (Download now)
EB5-3 Mobile and Variable Absorption Product that Includes Low Frequencies—Niels Adelman-Larsen, Flex Acoustics - Copenhagen, Denmark
At amplified music concerts, from medium sized venues to the biggest arenas, low frequency reverberation is known to be the primary source for an undefined sound with low clarity, even close to the loud speakers. Therefore, means for providing additional low frequency absorption is always a concern. Several layers of fabric at various distances from reflecting surfaces has usually been the best option. Still this method provides a relatively modest absorption coefficient in the important 63 and 125 Hz octave bands, while damping the high frequencies which the audience absorbs well, also due to the high Q of loud speakers at higher frequencies. A new, patented technology of inflated, ultra thin plastic membranes seems to solve this challenged in both multipurpose venues that need to adjust their acoustics at the push of a button, or in halls and arenas that only occasionally present amplified music and need to be treated for the event. This paper presents briefly the technology with cases from differently sized halls and arenas.
Engineering Brief 180 (Download now)
EB5-4 Ellipsoidal Reflector for Measuring Oto-Acoustic Emissions—Ville Pulkki, Aalto University - Espoo, Finland; Technical University of Denmark - Denmark; Vesa Heiskanen, Aalto University - Espoo, Finland; Bastian Epp, Technical University of Denmark - Denmark
A truncated prolate ellipsoidal reflector having the ear canal of a listener at one focal point and large-diaphragm low-noise microphone at the other focal point is proposed for free-field recordings of oto-acoustic emissions. A prototype reflector consisting of three pieces is presented, which enables measuring the response of the system with different truncations. The response of the system is measured with a miniature loudspeaker, and proof-of-concept measurements of oto-acoustic emissions are presented. The effect of truncation and other physical parameters to the performance of the system are discussed.
Engineering Brief 181 (Download now)
EB5-5 Key Sonic Characteristics Voice Identification Analysis and the Courts—Thomas Guzman-Sanchez, GS Media Lab - Northridge, CA, USA
The paper presents a voice identification analysis technique based on the analysis and comparison of four key sonic/acoustic characteristics. The proposed solution provides scientific method of analyzing voice or audio recordings and accessing similarities or differences for uses of identification. The technique utilizes five different types of preparation and analysis generating multiple results that can be applied for comparison. The function is similar to a police line-up except this is done with audio recordings. The proposed analysis will provide an accurate process in accessing voice identification.
Engineering Brief 182 (Download now)
