Quantitatively why live video requieres so much more bandwidth than
live audio. To explain quantitatively, a numerical example will be
helpful.

Hi,

As you stated, it requires much more bandwidth to transfer live video
than live audio, simply because there is more data per given time unit
(usually seconds) in a video clip than an audio clip.  These are just
generalizations, however, because different types of audio and video
each have different levels of compression, quality, size or depth, and
so on.  In general:

?Low-end video (low quality MPEG-1 compression) requires at least 1 megabit/sec
Full-motion, full-screen, "VHS quality" video requires between 4 and 6
megabits/sec."

[ http://www.ou.edu/class/standers/4683/bandwidt.html ] 

The chart on the above page should be very helpful and should
hopefully answer most of your question.  The various types of internet
connections are described, along with the amount of bandwidth (rate of
data per second) they provide and corresponding types of video or
audio streams that they can adequately carry as a result of that
bandwidth.

Also, some information about digital video as well as how data
compression can minimize the bandwidth requirements can be found at:
[ http://members.tripod.com/~levitm/whatis.htm ]


I trust these resources have shed light on your question, but if you
require a clarification, please request one, especially before rating
this answer.  Thank you for bringing this question to Google Answers!

Regards,
Andrewxmp

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