LG 47LW5700 Owner's Manual

When different audio types exist in an input signal, this function allows you to select the audio type

you want.
Mode
Auto

Automatically outputs in the order 

HE-AAC > Dolby Digital+ > Dolby Digital > 

MPEG or Dolby Digital+ > Dolby Digital > HE-AAC > MPEG.

Allows users to select the audio type they want.

ex) If 

MPEG is selected, MPEG is always outputted.

      If 

MPEG is not supported, another audio type is set in that order.

If the video and sound are not synced, you can adjust it manually.

(-) setting : Make audio output faster than the default.
(+) setting : Make audio output slower than the default.
Option
AV Sync.

Adjusts the sync of the TV speaker and SPDIF.

Adjusts the sync of the sound from the TV's internal speaker.

Adjusts the sync of the sound from an external speaker connected to the digital 

audio output port.