Eeyore wrote:

Dare one ask why ?

This is a consequence of complicated video signal processing inside flat
panel televisions - the picture takes more time to display than the
moment the matching sound comes to the speakers. Normally for a internal
video source, the sound has to be thus delayed to match the picture.

If an external source like a set top box, or DVD is used - and
pre-display audio is routed to an external amp/speaker system then lip
sync is an issue, unless a digital delay is added (typically receivers
have this as an option - and so do some set top boxes)

The "correct" answer is to get a proper television set with a full box
of glass and air behind it, decent contrast and dynamics, and no fancy
video processing nonsense ;-)

--
Adrian C