Keep in mind this is just me musing about what would be a nice feature
in digital TVs (and converter boxes), not something that actually
exists, so far as I know. The thread on how commercials are inevitably
louder reminded me of another common problem I've noticed: TV stations
have grossly different volume levels. I crank it up for channel 65, then
switch to 7 and the damn speaker nearly burns out.

So what would be nice would be a "volume normalization" function. Could
work lots of ways: easiest to implement, but most difficult for users,
would be a setup option that let you adjust the *relative* volume level
for each channel individually (probably just a simple +/- slider
control). When you tuned to that channel, it would retrieve this factor
and apply it to the current volume setting.

Better for the user, but harder to implement would be an
auto-normalization function that would run when you do a scan (or
rescan) of channels; it would take a short sample (say 5-10 seconds) of
each channel's audio and automatically calculate the normalization
factor, then store it. Of course, this would take a lot longer, and it's
not guaranteed that the sample time would be representative of that
channel's sound level.

This does nothing to alleviate the annoyance of loud commercials; it
would simply be a way of "leveling out" the sound level of TV stations
without requiring legislation, FCC regulation, etc.


--
Personally, I like Vista, but I probably won't use it. I like it
because it generates considerable business for me in consulting and
upgrades. As long as there is hardware and software out there that
doesn't work, I stay in business. Incidentally, my company motto is
"If this stuff worked, you wouldn't need me".

- lifted from sci.electronics.repair