Human Perception of Media Synchronization
Ralf Steinmetz and Clemens Engler, IBM European Networking Center,
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Paper describes a number of experiments designed to deliver hard data
regarding how much synchronization delay between related streams is
acceptable to human subjects. The required bounds range from very tight
(nanoseconds) for stereo audio to moderate (milliseconds) for
video/audio lipsyncing to loose (nearly a second) for
audio/telepointer. Video experiments were done using PAL, for which the
frame rate differs from NTSC; not clear whether the results should
really be measured in pure time or in frames.
One interesting result is that audio-leading-video sounds awkward
because we are used to adjusting internally for the slower speed of
sound relative to light.
Relevance to Multimedia
Provides some hard data (numbers) that system designers can use to tune
multimedia delivery systems, unlike survey papers (e.g. Roufs).
However, as in the Roufs survey, there are many variables in such
experiments, and the methodology and sample set size were not made
4 out of 5: even though methodology is sketchy, results are useful to
systems designers, not just perceptual psychologists.
Armando Fox (firstname.lastname@example.org)