| 2006 December, Volume 54 Number 12 |
CONTENTS
President's Message
Wieslaw Woszczyk 1139
PAPERS
Equalization in an Extended Area Using Multichannel Inversion and Wave Field Synthesis
E. Corteel 1140
Because of the nonideal directivity of loudspeakers in wave field synthesis, the conventional approach of individually equalizing each loudspeaker does not produce an accurate soundfield over an extended area of the listening space. A new method for equalization considers the full array of loudspeakers as a complete multiple-input multiple-output (MIMO) system. In the proposed multichannel inversion scheme, compensation is achieved for a limited ensemble of elementary virtual sources. Results show that the approach reduces rendering artifacts and spectral coloration over an extended listening area.
Filter Design Method for Loudspeaker Equalization Based on IIR Parametric Filters
Germán Ramos and José J. López 1162
Equalizing a loudspeaker using a cascade sequence of second-order sections (low-pass, high-pass, or peak filter) is a viable alternative to the more conventional approach of a single large FIR filter. In order to optimize the parameters of each filter section, a two-step algorithm begins by first searching for a good initial solution and then applying a heuristic method using subjective criteria. The solution is scalable, subjectively validated, and produces a computational cost reduction in comparison to the conventional approach for the same degree of performance.
Perceptually Biased Linear Prediction
Arijit Biswas and Albertus C. den Brinker 1179
In contrast to the standard linear prediction-based perceptual audio coding that uses a separate psychoacoustic model, the authors propose Laguerre-based linear prediction employing a perceptually biased solution. This greatly reduces the computational complexity because a separate psychoacoustic model is no longer required. Subjective listening tests show that the resulting audio quality is similar to that of the traditional approach.
ENGINEERING REPORTS
Application and Verification of the Objective Quality Assessment Method According to ITU Recommendation Series ITU-T P.862
Antti Kurittu, Juha Salmela, Olli Kirla, Ari Lakaniemi, Ville-Veikko Mattila, and Nick Zacharov 1189
In recent years a number of speech quality prediction algorithms have been developed for evaluating telecommunications systems. The family of ITU-T recommendation P.862 is frequently used to create a mean opinion score of quality. Although these algorithms have been evaluated under common testing conditions for narrow- and wide-band speech signals, care must be used when these standards are applied to channels more specialized degradations, such as spectral aberrations, time scaling, and environmental noise. This study has discovered certain cases of suboptimal accuracy. As with the use of all quality-metric tools, the user must heed their limitations and scope of applicability in order to avoid erroneous conclusions.
STANDARDS AND INFORMATION DOCUMENTS
AES Standards Committee News 1215
Personal computer audio quality measurements; storage environment for multiple media; polarity of audio signals; connectors for loudspeaker patch panels; analog recording; transfer technologies; storage and handling of media; digital library and archive systems; microphone measurement and characterization
FEATURES
121st Convention Report, San Francisco 1218
Exhibitors 1235
Program 1241
30th Conference Preview, Saariselkä, Finland 1294
Calendar 1296
Program 1297
Registration Form 1304
Forging Ahead with Spatial Audio Coding 1305
Education News 1314
Call for Nominations for the Board of Governors 1318
Call for Awards Nominations 1319
13th Regional Convention, Tokyo, Call for Papers 1324
Bylaws: Audio Engineering Society, Inc. 1325
Index to Volume 54 1329
DEPARTMENTS
News of the Sections 1309
Upcoming Meetings 1313
Sound Track 1315
New Products and Developments 1317
Membership Information 1320
Advertiser Internet Directory 1322
Sections Contacts Directory 1344
AES Conventions and Conferences 1352
FPO For the cover:
2006 December, Volume 54 Number 12
spine: 2006 December, Volume 54 Number 12