AES Berlin 2014
Engineering Brief Details
EB1 - Poster Session 1
Saturday, April 26, 15:00 — 16:30 (Foyer)
EB1-1 Remixing a Historic Film in Higher Order Ambisonics 3-D Audio—Workflow and Technical Solutions—Tobias Falke, Hamburg University of Applied Sciences - Hamburg, Germany; Johann-Markus Batke, Audio & Acoustics, Technicolor Research & Innovation - Hannover, Germany; Thomas Görne, Hamburg University of Applied Sciences - Hamburg, Germany
The project investigates the suitability of Higher Order Ambisonics (HOA) 3-D audio for the redesign and remix of historic film soundtracks. Technical and aesthetic challenges and hurdles are studied with scenes of a 1953 french classic. In order to obtain a high degree of immersion and on the other hand also to fix technical limitations of the historical material, some parts of the soundtrack were redesigned. The resulting HOA 3-D mix is claimed to be format agnostic, i.e., it is designed to be used on all common 3-D and also 2-D loudspeaker layouts, given the appropriate rendering system is provided.
Engineering Brief 130 (Download now)
EB1-2 Moving the Room... Acoustics, Around the Beamformer Beam—Georgios Flamis, Dialog Semiconductor - Patras, Greece; Maria Platypodi, Dialog Semiconductor - Patras, Achaia, Greece
As the demand for audio beamforming to commercial applications is increasing, the need for a robust evaluation method becomes apparent. In such applications, the beam is shaped by the microphone distribution and the directional response that the algorithm calculates. Thus, it will be located to the 3-D space with predefined acceptance angle. The performance of the beamforming system over the scenarios of noise reduction and echo control can be estimated once the beam location is properly defined. Presented are the methods of equalizing the sound production of background noise into the room acoustics, as well as the resulting conditions, under which the edges of the beam can be definable.
Engineering Brief 131 (Download now)
EB1-3 Spatial Sound for Mobile Navigation Systems—Wataru Sanuki, University of Aizu - Aizu, Japan; Julian Villegas, University of Aizu - Aizu Wakamatsu, Fukushima, Japan; Michael Cohen, University of Aizu - Aizu Wakamatsu-shi, Fukashima-ken, Japan
We have developed a mobile navigation system featuring binaural spatial sound delivered via headphones. “Machi-beacon” is intended to promote traffic and pedestrian safety: users select a destination relative to their current position, and the application renders both a visual map and an auditory earcon at the goal. The apparent location of this earcon is adjusted to reflect changes in orientation of the user by modulations of the interaural level difference. To disambiguate front and back directions, the earcon progressively changes between contrasting cues. By desaturating the visual modality, smartphone users can focus on their environment and its hazards and rewards.
Engineering Brief 132 (Download now)
EB1-4 Two Dimensional Gestural Control of Audio Processing—Tom Wilson, University of Huddersfield - Huddersfield, West Yorkshire, UK; Steven Fenton, University of Huddersfield - Huddersfield, West Yorkshire, UK
This project investigates the design of a 2-D, single, and multi-touch gesture set for the control of audio processing
commonly found within DAWS and mixing consoles. The recent popularity of touch pads has made wider application in this area possible. We describe the testing, analysis, and mapping of gestures to theorize the most efficient control over audio processing parameters. By improving the control interface, workflow efficiency could be greatly improved. A test was carried out that observed engineers as they carried out specific mixing tasks using standard Pro Tools plug-ins. In addition, a survey was constructed to determine the most popular gestures for common processing parameters. The workflow and recorded gestures were then analyzed and a set of optimized gesture based controls were produced.
Engineering Brief 133 (Download now)
EB1-5 Influence of Directional Differences of First Reflections in Small Spaces on Perceived Clarity—Hidetaka Imamura, Tokyo University of the Arts - Tokyo, Japan; Atsushi Marui, Tokyo University of the Arts - Adachi-ku, Tokyo, Japan; Toru Kamekawa, Tokyo University of the Arts - Adachi-ku, Tokyo, Japan; Masataka Nakahara, SONA Corp. - Tokyo, Japan
The ultimate goal of the research is to propose an acoustic measure of perceived clarity for small spaces such as studio control rooms and listening rooms. While C80 is somewhat successful in predicting the perceived clarity of sound in performance spaces, detailed research of clarity in small spaces has not been conducted. An experiment was conducted to investigate the perceived clarity of reproduced sound in small spaces with a focus on the arrival direction and delay time of the first reflections. Seven participants were asked to evaluate the sounds with loudspeaker simulated wall reflections in author-constructed temporal quasi-anechoic chamber. Variation of the first reflections did significantly influence perceived clarity and spatial impressions such as ASW, LEV, and spatial definition.
Engineering Brief 134 (Download now)
EB1-6 Multidimensional Ability Evaluation of Participants of Listening Tests—Tomasz Dziedzic, AGH University of Science and Technology - Krakow, Poland; Piotr Kleczkowski, AGH University of Science and Technology - Krakow, Poland
In this e-Brief, the problem of selecting proper participants for a listening test will be addressed. The authors will describe the idea of multidimensional ability evaluation of participants and present an initial version of application developed to perform preliminary ability evaluation tests. The software testing results and conclusions as well as a draft for future work are presented.
Engineering Brief 135 (Download now)
EB2 - Papers Session 1
Monday, April 28, 15:00 — 17:00 (Estrel Hall C1)
Chair:
Christopher Kling, Klangkantine - Darmstadt, Germany
EB2-1 Auto Adaptation of the Mobile Device Characteristics for Various Acoustic Conditions—Jozef Kotus, Gdansk University of Technology - Gdansk, Poland; Andrzej Ciarkowski, Gdansk University of Technology - Gdansk, Poland; Andrzej Czyzewski, Gdansk University of Technology - Gdansk, Poland
The proposed methodology of auto adaptation of the mobile device characteristics for various acoustic conditions was presented in the paper. The main purpose of this study was to determine the parameters of the acoustic path of the mobile device for both transmitting (speaker) and receiver (microphone). Results of the measurement characteristics of mobile devices were presented. Information about characteristics of the particular partials of the sound path were used to design and develop a technique of linearization of the device frequency response characteristics. Preliminary results obtained with the proposed methodology are presented. The performed research evolved into the design of an adaptive self-linearization method that compensates for the changing of acoustic conditions through continuous monitoring and regulating the audio settings.
Engineering Brief 136 (Download now)
EB2-2 The Sonic Characteristics of the Jazz Style Electric Bass Guitar—Bryan Martin, McGill University - Montreal, QC, Canada; Centre for Interdisciplinary Research in Music Media and Technology (CIRMMT) - Montreal, QC, Canada
The electric Jazz-style bass has long been established as a staple in jazz and popular music. This investigation seeks to measure and map the resonant, sonic, acoustic, and electromagnetic characteristics of the instrument and its constituent parts. The characteristics and constituents to be examined are the electromagnetic pickups, resonances in the body and neck, passive electronics, and electrical impedances. An analysis will examine their confluence and
contributions to the resultant sound of the instrument. While much has been published concerning the electric guitar and its pickups, there has been very little published concerning solid-body bass guitars.
Engineering Brief 137 (Download now)
EB2-3 New Studio Strategies in Music Production—The Disappearing Gap between Engineer and Producer—Christopher Kling
In an industry of shrinking music production budgets, it is common that the audio engineer and music producer happen to be the same person. New technologies as well as new system designs in hardware and software further enforce this transition—not only in project/home studios. In addition to the risks of this development, there are also benefits: New production and studio strategies enable engineers to be more flexible to the changing demands of clients and artists while working more cost-effectively. This involves changes in common studio architecture and setup and a different recording workflow through the use of new technologies in DAWs, as well as less distinction between recording and mixing. A few specific examples and perspectives will be given.
Engineering Brief 138 (Download now)
EB2-4 Compensation of Crossover Region Overshoot in Multiband Compression—David Traore, Beats Electronics, LLC - Santa Monica, CA, USA; Joshua Atkins, Beats Electronics, LLC - Santa Monica, CA, USA; Andrei Krishkevich, Beats Electronics - Santa Monica, CA, USA; Adam Strauss, Beats Electronics, LLC - Santa Monica, CA, USA
Overshoot in the crossover region of multiband dynamic range compression (DRC) systems is an issue that is encountered in several audio applications such as hearing aids, audio mastering tools, and portable loudspeaker systems. This overshoot translates into a loss of overall loudness due to reduced post scale headroom, digital clipping, or allowable output above a chosen threshold. This paper introduces a gain compensation filter in the limiter gain computation path in each band, thus preserving the audio quality and loudness of the system. Furthermore, a couple of methods for calculating the optimal compensation filter is presented along with analysis of the two and three band DRC systems with and without the proposed solution.
Engineering Brief 139 (Download now)
EB2-5 Multiphysical Simulation Methods for Loudspeakers—A (Never-)Ending Story?—Alfred Svobodnik, Konzept-X GmbH - Karlsruhe, Germany
Multiphysical simulations of loudspeakers have been investigated by scientific and industrial researchers for more than 40 years. At a first glance an electrodynamic loudspeaker seems to be a fairly simple assembly—a simple (sub-)system compared to typical applications of modern CAE methods. So where is the challenge? In detail! Besides strongly coupled different physical domains (electromagnetics, mechanics, acoustics, thermal transport, fluid dynamics ...), we also have to deal with path dependent dynamic effects and nonlinearities (including instabilities) in each domain. Additionally, materials with totally different behavior (and thus totally different material models to be used) and different joining techniques for each component are used as well. This paper will summarize challenges for realistic simulations and will discuss efficient solutions for daily usage in the industrial work flow of product development.
Engineering Brief 140 (Download now)
EB2-6 A Method for Comparison of Nonlinearities of Consumer Earphones Using Equalized Stimuli—Felix Fleischmann, Fraunhofer Institute for Integrated Circuits IIS - Erlangen, Germany; Jorgos Estrella, Fraunhofer Institute for Integrated Circuits IIS - Erlangen, Germany; Jan Plogsties, Fraunhofer Institute for Integrated Circuits IIS - Erlangen, Germany
Comparison of nonlinearities between different earphone models is not directly possible due to their different sensitivities and the high dynamics in the transducer's frequency response. Also, nonlinearities are highly dependent on the level of the excitation signal. An approach to overcome these differences and allow for fair comparison is proposed. The method is based on filtering commonly used stimuli like pink sweeps with a linear correction filter. This filter is obtained by a measurement at low input levels where the transducer shows linear behavior. The nonlinear response is then measured at different levels and THD is computed. In this way the non-linearity or different transducers can be compared directly. Some examples demonstrating the performance of consumer grade earphones are presented and discussed. The results show that nonlinearities mainly appear for low frequency excitation.
Engineering Brief 141 (Download now)
EB2-7 Design and Development of Auralization Room at Edinburgh Napier University—Elena Prokofieva, Edinburgh Napier University - Edinburgh, UK; C. Luciani, Edinburgh Napier University - Edinburgh, Scotland, UK; I. McGregor, Edinburgh Napier University - Edinburgh, Scotland, UK
The auralization room was designed as a joint project between School of Engineering and Built Environment and the School of Computing of Edinburgh Napier University. The interior acoustic design specialists conducted the acoustic design of the auralization room, while the expert in computing provided the electronic systems. The room is planned to be used for various purposes, for example on the simulation
of sound insulation of the partitions for proposed developments where the trial process is unrealistic under the real circumstances.
Engineering Brief 142 (Download now)
EB2-8 Comparative Results between Loudspeaker Measurements Using a Tetrahedral Enclosure and Other Methods—Geoff Hill, Hill Acoustics Limited - Leigh on Sea, Essex, UK
A major problem for the loudspeaker and transducer industries throughout the world, is an inability to rely upon measurements routinely exchanged between suppliers and customers. This paper updates "Consistently Stable Loudspeaker Measurements Using a Tetrahedral Enclosure" - EB4-7 published in 2013, with comparative measurements using results by other people, equipment and methods: Small IEC Baffle in Anechoic Chamber and Large IEC Baffle Outside vs a TTC 350. These Test Chambers give us the capability to approach "Design Quality" measurements easily throughout the entire supply chain, reducing errors and improving quality whilst driving down the cost of measurement.
Engineering Brief 143 (Download now)
EB3 - Poster Session 2
Tuesday, April 29, 10:00 — 11:30 (Foyer)
EB3-1 An Approach to Bass Enhancement in Portable Computers Employing Smart Virtual Bass Synthesis Algorithms—Piotr Hoffmann, Gdansk University of Technology - Gdansk, Poland; Tomasz Sanner, Gdansk University of Technology - Gdansk, Poland; Bozena Kostek, Gdansk University of Technology - Gdansk, Poland; Audio Acoustics Lab.
The aim of this paper is to present a novel approach to the Virtual Bass Synthesis (VBS) algorithms applied to portable computers. The developed algorithms are related to intelligent, rule-based setting of synthesis parameters according to music genre of an audio excerpt and to the type of a portable device in use. To find optimum synthesis parameters of the VBS algorithms, subjective listening tests based on a parametric procedure were performed. The classification of music genres is automatically executed employing MPEG 7 parameters and the Principal Component Analysis method applied to reduce information redundancy. The VBS algorithm performs the synthesis based on a nonlinear device (NLD) or phase vocoder (PV) depending on the content of an audio file excerpt. A soft computing (fuzzy logic) algorithm is employed to set optimum synthesis parameters depending on a given song.
Engineering Brief 144 (Download now)
EB3-2 Energy Based Traffic Density Estimation Using Embedded Audio Processing Unit—György Nagy, Fraunhofer Institute for Digital Media Technology IDMT - Ilmenau, Germany; Rene Rodigast, Fraunhofer Institute for Digital Media Technology IDMT - Ilmenau, Germany; Danilo Hollosi, Fraunhofer Institute for Digital Media Technology IDMT - Ilmenau, Germany
In this paper we present preliminary results of an audio-based traffic density estimation application, developed within the EU-FP7 project EAR-IT [1]. The algorithm exploits that the energy of environmental noise, generated by vehicles, is related to the prevalent traffic conditions. Noise analysis and derived restrictions were made to improve the solution, which was implemented on an embedded platform. This approach follows the current trends—distributed and local processing—and directly targets the requirements for smart cities and wireless sensor networks.
Using traffic monitoring wireless sensors, provided by the testbed SmartSantander [2], development setup was established to support the audio related algorithm deployment, testing, and assessment.
Engineering Brief 145 (Download now)
EB3-3 Objective Evaluation Method for the Perceived Quality of Car Horns—Taejin Shin, Inha University - Inchon, Korea; Sang-Kwon Lee, Inha University - Inchon, Korea
This paper presents an objective evaluation method for the perceived quality of car horn sound based on a psychoacoustic metric and a subjective test. A new psychoacoustic metric called the “spectrum decay (SD) slope” was developed to evaluate a luxury timbre in the sound quality of the horn sound. Eight synthetic sounds with a variety of SDS slope are designed. The synthetic sounds are subjectively evaluated by 41 subjects. A sound quality index for car horn sound is developed based on the correlation between the SD slope and subjective rating for synthetic sounds. The sound quality index is applied to the estimation of the sound quality of horn sounds of ten passenger cars measured inside the cars. The measured horn sounds are also evaluated subjectively by the same 41 subjects. The correlation between the estimated subjective rating and the subjective rating evaluated by the subjects is sufficient (R= 0.93, p <0.01) for the validation of the sound quality index.
Engineering Brief 146 (Download now)
EB3-4 Fitting the Mobile Device Characteristics to the User's Hearing Preferences—Kuba Lopatka, Gdansk University of Technology - Gdansk, Poland; Piotr Suchomski, Gdansk University of Technology - Gdansk, Poland; Andrzej Ciarkowski, Gdansk University of Technology - Gdansk, Poland; Piotr Odya, Gdansk University of Technology - Gdansk, Poland; Andrzej Czyzewski, Gdansk University of Technology - Gdansk, Poland
A method for fitting the mobile computer audio characteristics to the user's hearing preferences is proposed. The process consists of two stages: calibration and dynamics processing. During the calibration phase the user performs a loudness scaling test giving their response regarding the perceived loudness. The dynamics processing made on above basis sets the loudness to the most comfortable level. The processing accounts both for the user's hearing preferences (or possible deficiencies) and for the playback characteristics of the device. The solution is implemented as a standalone PC calibration application and as an APO object installed in the system's audio driver.
Engineering Brief 147 (Download now)
EB3-5 Recreating Robb: The Sound of the World’s First Electronic Organ—Michael Murphy, Ryerson University - Toronto, ON, Canada; Max Cotter, Ryerson University - Toronto, Ontario, Canada
This paper follows up from a 2013 AES presentation reporting on the recreation of the sound of the Robb Wave Organ, the first successful electronic organ, prototyped in 1927. The organ employed primitive “PCM-like” sampling techniques in its tone wheel construction. Our work has led to the compilation of recordings of the last known organ into a MIDI-operable cross-platform sample library for public use, bringing the instrument back to life and out of obscurity. The presentation will feature playable sample sets as well as audio comparisons between the Wave organ and the pipe organs it attempted to reproduce. Audiences will be encouraged to interact with the instrument while gaining a sense of its history and contribution to early sample-based synthesis.
Engineering Brief 148 (Download now)
EB3-6 Reproduction of the Radiation Pattern from a Practical Source by an Acoustic Array and the Equivalent Source Method—Wan-Ho Cho, Korea Research Institute of Standards & Science - Yuseonggu, Daejeon, Korea
Complicated radiated patterns and strengths from actual source can be approximately described by the expansion of spherical harmonics or, in other words, ideal sources, in various orders. If the signals are superposed to meet the requirement for generating a specially designed radiation pattern of ideal sources in various orders, an arbitrary radiation pattern simulating the actual source of interest can be reproduced by this designed filter. The method based on the equivalent source method is proposed to design a source array to reproduce not only frequency response but also the spatial response to simulate the sound field, and the suggested method is applied to reproduce the radiation pattern of musical instruments with spherically distributed loudspeaker array.
Engineering Brief 149 (Download now)
EB4 - Papers Session 2
Tuesday, April 29, 15:00 — 16:30 (Estrel Hall B)
Chair:
Brecht De Man, Queen Mary University of London - London, UK
EB4-1 Creating Dynamic Psychoacoustic Maps of Hearing Threats for Outdoor Concerts Employing Supercomputing Grid—Jozef Kotus, Gdansk University of Technology - Gdansk, Poland; Maciej Szczodrak, Gdansk University of Technology - Gdansk, Poland; Karolina Marciniuk, Gdansk University of Technology - Gdansk, Poland; Andrzej Czyzewski, Gdansk University of Technology - Gdansk, Poland; Bozena Kostek, Gdansk University of Technology - Gdansk, Poland; Audio Acoustics Lab.
The auditory effects caused by the outdoor concert are discussed in this paper. The analysis is based on the computation results obtained by means of supercomputing PL-Grid infrastructure and specific computational algorithms developed by the authors. The software consists of the outdoor sound propagation module and psychoacoustical noise dosimeter. The simulation was performed by means of real music recordings and the following outdoor propagation conditions were taken into account: speaker directivity, ground effect, building reflection, distance attenuation, and sound absorption by the atmosphere. On the basis of the proposed methodology the dynamic (one minute time resolution) psychoacoustic maps of hearing threats for considered area were created expressed by TTS (Temporary Threshold Shift) values in critical bands. Moreover, the results include also maps of sound level and noise dose values.
Engineering Brief 150 (Download now)
EB4-2 APE: Audio Perceptual Evaluation Toolbox for MATLAB—Brecht De Man, Queen Mary University of London - London, UK; Joshua D. Reiss, Queen Mary University of London - London, UK
We present a toolbox for multi-stimulus perceptual evaluation of audio samples. Different from MUSHRA (typical for evaluating audio codecs), the audio samples under test are represented by sliders on a single axis, encouraging careful rating, relative to adjacent samples, where both the reference and anchor are optional. Intended as a more flexible, versatile test design environment, subjects can rate the same samples on di fferent scales simultaneously, with separate comment boxes for each sample, an arbitrary rating scale, and various randomization options. Other tools include a pairwise evaluation tool and a loudness equalization stage. We discuss some notable experiences and considerations based on various studies where these tools were used. We have found this test design to be highly effective when perceptually evaluating qualities pertaining to
music and audio production.
Engineering Brief 151 (Download now)
EB4-3 Principals of a Tunable Diaphragmatic Bass Absorber—Philippe Jeansonne, McGill University - Montreal, QC, Canada; Centre for Interdisciplinary Research in Music Media and Technology (CIRMMT) - Montreal, QC, Canada
Once propagated in air, low frequency energy can be difficult to attenuate without physically prominent bass absorbers. The tunable diaphragmatic bass absorber fulfills this task in a discrete way. Mounted on an aluminum frame, a tunable membrane is separated by a thin air-gap to a layer of acoustic fibergalss. The membrane's excitation is restricted by the layer of acoustic fiberglass resulting in attenuation of a desired range of low frequencies. The proposed use for this new design is to attenuate a particular LF room mode or its harmonic.
Engineering Brief 152 (Download now)
EB4-4 A Motorized Telescope Mount as A Computer-Controlled Rotational Platform for Dummy Head Measurements—Matthew Shotton, BBC R&D - London, UK; Chris Pike, BBC Research and Development - Salford, Greater Manchester, UK; University of York - Heslington, York, UK; Frank Melchior, BBC Research and Development - Salford, UK
This paper covers the construction and validation of an affordable and accurate two degree-of-freedom rotational mount for making HRTF (head-related transfer function) and BRIR (binaural room impulse response) measurements using a dummy head microphone. We review the design requirements for a rotational mount in the context of measurements for binaural rendering, with reference to perceptual factors. In order to achieve a low-cost solution, we evaluate the suitability of a motorized telescope mount. Issues considered during design of the system are discussed. The use of affordable electronics to convert the mount into a general-purpose computer-controlled rotational platform is presented, as well as objective measurements to validate performance. Finally the limitations of this system are discussed and further use cases proposed.
Engineering Brief 153 (Download now)
EB4-5 Measurements and Visualization of Sound Intensity around the Human Head Using Acoustic Vector Sensor—Jozef Kotus, Gdansk University of Technology - Gdansk, Poland; Magdalena Plewa, Gdansk University of Technology - Gdansk, Poland; Bozena Kostek, Gdansk University of Technology - Gdansk, Poland; Audio Acoustics Lab.
Measurements and visualization of sound intensity around a human head are presented in this paper. The sound intensity field was obtained by means of a Cartesian robot that was applied to precise positioning of the acoustic vector sensor. Measurements were performed in the free field using a head and torso simulator and a configuration of either one, two, or four loudspeakers. The acoustic vector sensor was positioned around the head with 5 cm step. Sound intensity was measured in 277 points. During every step the three orthogonal sound intensity components were calculated. Tonal signals for frequencies: 250, 500, 1000, 2000, 4000, and 8000 Hz were applied. Obtained results
were used to prepare visualizations of sound intensity distribution around the human head.
Engineering Brief 154 (Download now)
EB4-6 Spatial Audio Objects Recording Using Wireless Acoustic Sensor Networks—Tomasz Zernicki, Zylia sp. z o.o. - Poznan, Poland; Piotr Szczechowiak, Zylia sp. z.o.o. - Poznan, Poland; Lukasz Januszkiewicz, Zylia sp. z.o.o. - Poznan, Poland; Marcin Chryszczanowicz, Zylia sp. z.o.o. - Poznan, Poland
This paper presents the development of a prototype system, which would be able to capture spatial audio scene using a wireless acoustic sensor network (WASN). Sound recording is performed in real-time by microphones embedded in each sensor node. Proposed approach is focused on processing of spatial audio objects instead of multichannel audio representation. It gives the flexibility of sound processing, mastering, and reproduction on different sound systems. This paper discusses key aspects and technologies used to build a prototype system, which are related to time synchronization of captured sounds, wireless protocols, sound source separation, and 3-D audio compression.
Engineering Brief 155 (Download now)
