diff --git a/src/Main/options.cxx b/src/Main/options.cxx
index e4992e5..1021852 100644
--- a/src/Main/options.cxx
+++ b/src/Main/options.cxx
@@ -133,7 +133,8 @@ void fgSetDefaults ()
     fgSetBool("/sim/startup/fullscreen", false);
     fgSetBool("/sim/menubar/visibility",false);
 
-    //fgSetBool("/sim/model/occupants",false); // 不显示飞行员
+    fgSetBool("/sim/sound/tishi/enabled",true);
+    fgSetBool("/sim/model/occupants",false); // 不显示飞行员
     
     fgSetBool("/sim/rendering/photoscenery/enabled",true);  //打开卫星地景