| 2005 January/February, Volume 53 Number 1/2 |
CONTENT
New Editor of the Journal
Theresa Leonard 3
PAPERS
Development and Initial Validation of a Multichannel Audio Quality Expert System
S/lawomir Zielinski, Francis Rumsey, Rafael Kassier, and Søren Bech 4
When a fixed channel bandwidth must be allocated among different types of services, such as sound, picture, and data, the audio engineer must arbitrate among conflicting demands on bandwidth. Is it better to have a lesser number of high-quality channels or more channels of lower quality? This research creates a predictive measure of graceful degradation with limited audio channel capacity. Subjective tests confirm that the proposed objective metrics predict audio quality as a function of channel bandwidth, as a function of down-mix algorithm, and as a combination of both.
A New Cognitive Model of Objective Assessment of Audio Quality
Jayme Garcia Arnal Barbedo and Amauri Lopes 22
The objective measures provided by the current ITU Perceptual Evaluation of Audio Quality psychoacoustic standard fail to match the subjective experience under many conditions. An alternative model based on a cognitive model improves the correlation between subjective and objective measures. The new model extracts a set of parameters from the audio signal, which are then mapped into a single metric to predict subjective quality. Six cognitive parameters are extracted from a filter-bank model.
ENGINEERING REPORTS
Multiple Piano Note Identification Using a Spectral Matching Method with Derived Patterns
L. I. Ortiz-Berenguer, F. J. Casajús-Quirós, and S. Torres-Guijarro 32
Detecting the component notes in a chord depends upon the particular musical instrument. By restricting the research to piano chords, and by using a spectral pattern-matching technique, the proposed approach successfully identifies up to four components of the chord. Chords are analyzed note by note, iteratively removing the contribution of each once identified. Spectral patterns of notes, derived from an acoustic model of a piano, were determined during a training session.
Auditory Evacuation Beacons
Sander J. van Wijngaarden, Adelbert W. Bronkhorst, and Louis C. Boer 44
Conventional auditory beacons, emergency sounds that guide people to a safe exit when vision is obscured by smoke, use modulated noise. But such signals also require explicit verbal instructions in order to navigate to an exit. A new signal was designed as a combination of a chime sound with a spoken message. In a tunnel environment without prior instructions to the participants, the evacuation success rate was 16% for conventional beacons and 87% for the newly designed beacons. Furthermore, by exploiting the precedence effect through the application of time delays, 88% of the participants were able to follow the sound to its location in a simulated ship's interior.
STANDARDS AND INFORMATION DOCUMENTS
Standards in print; digital audio connectors; calls for comment on shielding and MADI; reorganization of SC-06;digital audio measurement; input/output interfacing; audio file transfer 54
FEATURES
117th Convention Report, San Francisco 58
Exhibitors 74
Program 79
The Software Studio in the Age of Audio Networking 124
Some Thoughts on the Dynamics of Reproduced Sound Neville Thiele 130
Education News 133
12th Regional Convention, Tokyo, Call for Papers 150
27th Conference, Copenhagen, Call for Papers 151
119th Convention, New York, Call for Papers 152
DEPARTMENTS
News of the Sections 135
Upcoming Meetings 139
Sound Track 140
New Products and Developments 141
Available Literature 142
Membership Information 143
Advertiser Internet Directory 147
In Memoriam 149
Sections Contacts Directory 153
AES Conventions and Conferences 160
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2005 January/February, Volume 53 Number 1/2
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