diff --git a/Projekte/battleship/client/src/main/java/pp/battleship/client/BackgroundMusic.java b/Projekte/battleship/client/src/main/java/pp/battleship/client/BackgroundMusic.java
index 5cf97451..506d2520 100644
--- a/Projekte/battleship/client/src/main/java/pp/battleship/client/BackgroundMusic.java
+++ b/Projekte/battleship/client/src/main/java/pp/battleship/client/BackgroundMusic.java
@@ -1,6 +1,5 @@
 package pp.battleship.client;
 
-import com.jme3.app.Application;
 import com.jme3.audio.AudioData.DataType;
 import com.jme3.audio.AudioNode;
 import com.jme3.audio.AudioSource.Status;
@@ -15,7 +14,7 @@
 public class BackgroundMusic implements GameEventListener {
     private static final String VOLUME_PREF = "volume";
     private static final String MUSIC_ENABLED_PREF = "musicEnabled";
-    private Preferences prefs = Preferences.userNodeForPackage(BackgroundMusic.class);
+    private static final Preferences prefs = Preferences.userNodeForPackage(BackgroundMusic.class);
 
     static final Logger LOGGER = System.getLogger(BackgroundMusic.class.getName());
 
@@ -98,6 +97,11 @@ public void stop(AudioNode audioNode) {
         }
     }
 
+    /**
+     * pauses the given audi node
+     *
+     * @param audioNode the audio node to be paused
+     */
     public void pause(AudioNode audioNode) {
         if (audioNode.getStatus() == Status.Playing) {
             audioNode.pause();
diff --git a/Projekte/battleship/client/src/main/java/pp/battleship/client/MainVolume.java b/Projekte/battleship/client/src/main/java/pp/battleship/client/MainVolume.java
index d9539dc8..53ad1fa1 100644
--- a/Projekte/battleship/client/src/main/java/pp/battleship/client/MainVolume.java
+++ b/Projekte/battleship/client/src/main/java/pp/battleship/client/MainVolume.java
@@ -1,13 +1,11 @@
 package pp.battleship.client;
 
-import pp.battleship.model.Battleship;
-
 import java.lang.System.Logger;
 import java.lang.System.Logger.Level;
 import java.util.prefs.Preferences;
 
 public class MainVolume {
-    private Preferences prefs = Preferences.userNodeForPackage(MainVolume.class);
+    private static final Preferences prefs = Preferences.userNodeForPackage(MainVolume.class);
     private static final String MAIN_VOLUME_PREFS = "MainVolume";
     static final Logger LOGGER = System.getLogger(MainVolume.class.getName());