A:
You can either mute them, or select "External Speakers" in the menu:
Menu > Sound > Speaker Settings > ENTER
When you set Speaker Select to External Speaker, the TV’s speakers are turned off. You will hear sound through the external speakers only.
When you set Speaker Select to TV Speaker, both the TV’s speakers and the external speakers are on. You will hear sound through both.
Thanks for your interest in Samsung televisions.
--Mr.Samsung