AES San Francisco 2008
Paper Session P3
Thursday, October 2, 2:30 pm — 4:30 pm
P3 - Audio for Broadcasting
: Marshall Buck
, Psychotechnology, Inc. - Los Angeles, CA, USAP3-1 Graceful Degradation for Digital Radio Mondiale (DRM)
—Ferenc Kraemer, Gerald Schuller
, Fraunhofer Institute for Digital Media Technology - Ilmenau, Germany
A method is proposed that is able to maintain an adequate transmission quality of broadcasting programs over channels strongly impaired by fading. Although attempts of providing Graceful Degradation are manifold, the so called “brick wall effect” is inherent in most digital broadcasting systems. The main concept of the proposed method focuses on the open standard Digital Radio Mondiale (DRM). Our approach is to introduce an additional low bit rate parallel backup audio stream alongside the main radio stream. This backup stream bridges occurring dropouts in the main stream. Two versions are evaluated. One uses the standardized HVXC speech codec for encoding the parallel backup audio stream. The other version additionally uses a specially developed sinusoidal music codec.
Convention Paper 7517 (Purchase now)P3-2 Factors Affecting Perception of Audio-Video Synchronization in Television
—Andrew Mason, Richard Salmon
, British Broadcasting Corporation - Tadworth, Surrey, UK
The increasing complexity of television broadcasting, has, over the decades, resulted in an increased variety of ways in which audio and video can be presented to the audience after experiencing different delays. This paper explores the factors that affect whether what is presented to the audience will appear to be correct. Experimental results of a study of the effect of video spatial resolution are included. Several international organizations are working to solve technical difficulties that result in incorrect synchronization of audio and video. A summary of their activities is included. The Audio Engineering Society Standards Committee has a project to standardize an objective measurement method, and a test signal and prototype measurement apparatus contributed to the project are described.
Convention Paper 7518 (Purchase now)P3-3 Absolute Threshold of Coherence Position Perception between Auditory and Visual Sources for Dialogs
, U. Tecnológica de Chile INACAP - Santiago, Chile; Manuel Recuero
, Universidad Politécnica de Madrid - Madrid, Spain; Diego Duran, Manuel Gazzo
, U. Tecnológica de Chile INACAP - Santiago, Chile
Under certain conditions, auditory and visual information are integrated into a single unified perception, even when they originate from different locations in space. The main motivation for this study was to find the absolute perception threshold of position coherence between sound and image, when moving the image across the screen and when panning the sound. In this manner it is possible to subjectively quantify, by means of the constant stimulus psychophysical method, the maximum difference of position between sound and image considered coherent by a viewer of audio-visual productions. This paper discusses the accuracy necessary to match the position of the sound and its image on the screen. The results of this study could be used to develop sound mixing criteria for audio-visual productions.
Convention Paper 7519 (Purchase now)P3-4 Clandestine Wireless Development During WWII
, Scientific Conversion, Inc., Crypto-Museum - CA, USA
We describe the many advances in spy radios during and after WWII, starting with the huge suitcase B2 suitcase transceiver, through several stages of miniaturization and eventually down to small modules a few inches in size just after the War. A top secret navigation set known as the S-Phone, provided navigation and full duplex voice communications at 380 MHz between clandestine agents, partisans, ships, and planes. The surprising sophistication and fast progress will be illustrated with many photographs and schematics from the collection of the Crypto-Museum. This multimedia presentation includes vintage era music and radio clips as well as original WWII propaganda graphics.
Convention Paper 7520 (Purchase now)