This .ext works in your mission... PERIOD !!!
class CfgSounds
{
sounds[] = {alsatianBark, sound2};
class alsatianBark
{
name = "alsatianBark";
sound[] = {\sound\alsatianBark.ogg, db - 20, 1.0};
titles[] = {0, ""};
};
class sound2
{
name = "sound2";
sound[] = {\sound\sound2.ogg, db + 0, 1.0};
titles[] = {0, ""};
};
};
class CfgMusic
{
tracks[] = {music1, music2};
class music1
{
name = "music1";
sound[] = {\music\music1.ogg, db + 0, 1.0};
titles[] = {0, ""};
};
class change
{
name = "music2";
sound[] = {\music\music2.ogg, db + 0, 1.0};
titles[] = {0, ""};
};
};
class CfgEnvSounds
{
sounds[] = {Ambience1};
class Ambience1
{
name = "Ambience1";
sound[] = {\sound\Ambience1.ogg, db + 0, 1.0};
soundNight[]={"Ambience1.ogg",db-40,0,1};
title = "";
};
};
This works for me, hope it's the same for you

Only sure about the CfgSounds part so far...