AES Budapest 2012
Poster Session P11
P11 - Quality Evaluation and Spatial Audio
Friday, April 27, 12:30 — 14:00 (Room: Foyer)
P11-1 Influence of Resolution of Head Tracking in Synthesis of Binaural Audio—Mikko-Ville Laitinen, Tapani Pihlajamäki, Stefan Lösler, Ville Pulkki, Aalto University - Espoo, Finland
The use of head tracking in binaural synthesis of spatial sound increases the quality of reproduction. The required quality of a head-tracking system for this purpose is the topic of interest in this paper. A listening test was performed to evaluate the effect of four common sources of error in head-tracking systems. The listeners rated the naturalness of binaural reproduction in different head-tracking conditions. According to the test, the main requirement for the head-tracking system is to obtain an accurate and unrestricted azimuth angle. Furthermore, lower update rate of the tracking system affects the quality. The results showed prominent dependence on program material, and individual differences were also notable.
Convention Paper 8623 (Purchase now)
P11-2 Objective and Subjective Tests of Consumer-Class Audio Devices—Marek Pluta, Pawel Malecki, AGH University of Science and Technology - Krakow, Poland
The paper presents a new stand for subjective listening tests in the Department of Mechanics and Vibroacoustics of Krakow University of Science and Technology, as well as a procedure and results of preliminary tests that utilize it. The most important difference, compared to the previously used stand, is exclusion of an analog mixing console, which reduces the length of electroacoustic channel, and substituting active studio monitors with 12 pairs of closed headphones in order to provide a larger group of listeners with the same listening conditions. The tests study popular consumer audio reproduction devices, therein standalone and motherboard integrated sound cards, as well as portable players. The research included measurements and comparison of objective parameters, as well as ABX method listening test, with a studio-class audio interface as a reference device. A group of listeners of various professional profiles, including students of the Academy of Music in Krakow and Acoustic Engineering of Krakow University of Science and Technology, took part in these listening tests. Results are compared to the data obtained using the previous test stand.
Convention Paper 8624 (Purchase now)
P11-3 Subjective Evaluations of Perspective Control Microphone Array (PCMA) —Hyunkook Lee, University of Huddersfield - Huddersfield, UK
Perspective Control Microphone Array (PCMA) is a technique that allows one to flexibly render spatial audio images depending on the desired virtual listening position in a reproduced sound field. Two subjective listening experiments have been conducted to evaluate the effectiveness of PCMA on the controls over the perceived source/ensemble distance and width attributes. The first experiment verified a hypothesis suggesting that perceived width would decrease as source-listener distance increased, using anechoic trumpet and conga sources convolved with binaural impulse responses of a concert hall. It was shown that the distance and width linearly changed at doubled distances and were negatively correlated. The second experiment tested three reference virtual array configurations of PCMA on the same attributes using the same sources. The results agreed with the perceptual patterns observed in the concert hall situation in that there was a linear decrease in perceived width at an increased perceived distance. The main effect of PCMA configuration was found to be statistically significant. These results seem to strongly validate the effectiveness of PCMA for postproduction and user-interactive applications.
Convention Paper 8625 (Purchase now)
P11-4 Objective Profiling of Perceived Punch and Clarity in Produced Music—Steven Fenton, Jonathan Wakefield, University of Huddersfield - Huddersfield, UK
This paper describes and evaluates an objective measurement that profiles a complex musical signal over time in terms of identification of dynamic content and overall perceived quality. The authors have previously identified a potential correlation between inter-band dynamics and the subjective quality of produced music excerpts. This paper describes the previously presented Inter-Band Relationship (IBR) descriptor and extends this work by conducting more thorough testing of its relationship to perceived punch and clarity over varying time resolutions. A degree of correlation is observed between subjective test scores and the objective IBR descriptor suggesting it could be used as an additional model output variable (MOV) to describe punch and clarity with a piece of music. Limitations have been identified in the measure however and further consideration is required with regard to the choice of threshold adopted based on the range of dynamics detected within the musical extract and the possible inclusion of a gate as utilized in some loudness algorithms.
Convention Paper 8626 (Purchase now)
P11-5 A Hybrid Method Combining Synthesis of a Sound Field and Control of Acoustic Contrast—Martin Bo Møller, Martin Olsen, Bang & Olufsen a/s - Struer, Denmark; Finn Jacobsen, Technical University of Denmark - Lyngby, Denmark
Spatially confined regions with different sound field characteristics, in the following referred to as sound zones, may be desired in some situations. Recently, various sound field control methods for generating separate sound zones have been proposed in the literature. The different algorithms introduce different levels of control over the physical characteristics of the resulting sound fields. This paper introduces a hybrid of two existing methods employed for obtaining sound zones: “Energy Difference Maximization” for control of the sound field energy distribution and “Pressure Matching,” which contributes with synthesis of a desired sound field. The hybrid method introduces a tradeoff between acoustic contrast between two sound zones and the degree to which the phase is controlled in the optimized sound fields.
Convention Paper 8627 (Purchase now)
P11-6 Validation of Room Plane Wave Decomposition as a Tool for Spatial Ecogram Analysis of Rooms—Ana Torres, Universidad de Castilla La Mancha - Ciudad Real, Castile-La Mancha, Spain; Jose J. Lopez, Technical University of Valencia - Valencia, Spain; Basilio Pueo, Universidad de Alicante - Alicante, Spain
The classical point based analysis of sound attributes in room acoustics are not usually enough for analyzing the acoustic complexity of a room. Some spatial attributes that provide more information are been employed. Circular arrays of microphones and the subsequently plane wave decomposition have been proposed in the literature and employed successfully by the authors and others. In this paper we validate our previous work comparing the resulting measured echograms with the simulation of the room acoustics using a basic room acoustics modeling software, ROOMSIM, freely available. The resulting echograms of both methods are compared identifying strengths and weaknesses of the measurement method based on circular arrays and proposing some ideas for a future more in deep analysis.
Convention Paper 8628 (Purchase now)
