Dave Plowman (News) wrote:

In article zaQaj.261484$Fc.202074@attbi_s21,
Chuck ! wrote:

It's nearly too late now since the new TV's have AVL built-in to adjust
volume increases during commercials, but I am very surprised nobody ever
built a "good" add-on aftermarket volume-leveler all these years. Why
would it be so hard to build a good yet inexpensive one?


Have you heard the results of these built in ones? Ok, I suppose, if your
standards stop at AM radio quality.

The snag with this sort of device is it has to have a fast attack time to
work and a fairly slow recovery. And will work on any programme peak - not
just commercials. Make it fast attack and fast recovery and background
sounds will pump up and down - most unpleasant.


I am replying without first searching the web, but I do remember seeing
adverts over the years for a variety of ALC devices for TVs; the good ones
IIRC used to inspect the vertical interval for clues to program changes,
and also used timing heuristics to predict commercial placement. I
believe that such a device using learning algorithms with human training
input would have been _very_ effective, after all, at least in the U.S.
on major networks, a human can very easily predict when commercials occur
and when the level is excessive.

Regards,

Michael