As long as I´m playing on the campaign map I have no problems with any sound or music. But as soon as I start a battle the music stops. I can still hear the units marching or confirming orders. But no weather effects. You can see the rain or even the thunder but there is only silence. That´s a huge athmosphere killer.
Back on the campaign map the problem remains. I have no sound when watching video and there is also no longer a campaign map background music. Only some sounds I can hear. F.e. when the paper appears that an enemy Daimyo died you hear some sentences or when hitting the End Turn button.