Volume 56 Number 12 2008 December

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Editor’s Note, 2008 Reviewers (PDF-73KB)                John Vanderkooy    1035
Efficient Algorithms and Structures for Fractional Delay Filtering Based on Lagrange Interpolation (PDF-675KB) (HI-RES PDF-7.6MB)  
Andreas Franck    1036
Fractional delay filters, which allow for delays that are not aligned at samples values, are important in many signal processing algorithms. Lagrange interpolation is frequently used for this purpose in situations where delay values change frequently, because filter coefficients can be calculated from explicit formulas. The large number of algorithms for Lagrange interpolation necessitates an analysis of their computational effort. A novel structure that is efficient, scalable, and well suited for parallel hardware or software implementation is described.  

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Hierarchical Bandwidth Limitations of Surround Sound—Part I: Psychoacoustically Hierarchical Transform (PDF-379KB) (HI-RES PDF-4.3MB)  
Yu Jiao, Sławomir Zieli´nski, and Francis Rumsey    1057
In order to reduce the increase data rate of multichannel surround sound, a hierarchical bandwidth limiting technique is proposed. In this approach, the original signals are transformed into a hierarchical representation, which is then band-limited and re-transformed back into the original representation. Subjective listening tests were used to evaluate two such approaches: Gerzon MSBTF and Karhumen–Lòeve transforms. The results showed that the signal-dependent hierarchical encoding performed better than the signal-independent techniques, but both techniques were better than conventional methods.  

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Parallel Look-Ahead Digital SDM with Energy-Balance Binary Comparator (PDF-1.0MB) (HI-RES PDF-14.5MB)  
Malcolm Omar Hawksford    1069
Because conventional sigma–delta modulators have a proclivity toward instability when excited by high-amplitude audio signals, a modified detection process incorporates an energy metric. This new paradigm uses the sums of the energy in the filter integrators as part of the five-sample look-ahead. Unlike a conventional sigma–delta modulator, which only considers the filter output, this approach also lowers the stored energy within the filter. As an intrinsic tradeoff, increased stability at high levels increases noise modulation. An energy-balance algorithm can use a highly parallel matrix operation for computational efficiency.  

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All-Pass Linear Arrays (PDF-445KB) (HI-RES PDF-5.5MB)  
Michael M. Goodwin    1090
When using multiple drivers in a linear array structure to achieve an increased soundfield level, the designer must consider the spatially dependent frequency response of the array. By using specifically designed weights for the array elements, the array can be made to have a spatial all-pass characteristic such that there is minimal variation in the frequency response of the array with respect to angle. Weights that achieve this property correspond to FIR filter approximations of all-pass filters. A search algorithm for such approximations is described, and examples are provided to demonstrate the design freedoms of the proposed approach, including the use of crossover-filter configurations.  

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Correction to “Nonlinear Distortion Synthesis Using the Split-Sideband Method, with Applications to Adaptive Signal Processing”  
V. Lazzarini, J. Timoney, and T. Lysaght (PDF-45KB)    1102
AES Standards Committee News (PDF-181KB)    1104
Preferred sampling frequencies; serial transmission format; flutter measurement; serial multichannel interface; extended file format for audio; ATM networks; analog recording; transfer technologies; grounding & EMC  
125th Convention Report, San Francisco (PDF-3.3MB)    1106
     Exhibitors (PDF-1.1MB)    1120
Are You Hearing What I’m Hearing? (PDF-984KB)    Francis Rumsey    1126
How FCC “White Space” Decision Will Affect U.S. Pro Audio (PDF-350KB)    David Josephson    1132

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Education News (PDF-227KB)    Jason Corey    1136
127th Convention, New York, Call for Papers (PDF-33KB)    1150
Index to Volume 56 (PDF-219KB)    1152
News of the Sections (PDF-183KB)    1138
Sound Track (PDF-75KB)    1141
Upcoming Meetings (PDF-43KB)    1142
New Products and Developments (PDF-43KB)    1142
Membership Information (PDF-181KB)    1143
Advertiser Internet Directory (PDF-105KB)    1145
In Memoriam (PDF-111KB)    1149
AES Annual Report (PDF-47KB)    1151
Sections Contacts Directory (PDF-153KB)    1168
AES Conventions and Conferences (PDF-115KB)    1176
Cover & Sustaining Members List (PDF-94KB)    
AES Officers, Committees, Offices & Journal Staff (PDF-83KB)    
Advertisements (PDF-1.6MB)    
125th Convention Papers (Insert) (PDF-56KB)    
125th Convention Audio Recordings (Insert) (PDF-1.1MB)