Index: code/sound/sound.cpp
===================================================================
--- code/sound/sound.cpp	(revision 6523)
+++ code/sound/sound.cpp	(working copy)
@@ -1396,7 +1396,7 @@
 
 void snd_adjust_audio_volume(int type, float percent, int time)
 {
-	Assert( type >= 0 && type < 4 );
+	Assert( type >= 0 && type < 3 );
 	
 	switch (type) {
 	case AAV_MUSIC:
@@ -1420,6 +1420,8 @@
 		else
 			aav_data[type].delta = percent - aav_effect_volume;
 		break;
+	default:
+		Int3();
 	}
 
 	aav_data[type].delta_time = time;