diff --git a/src/test/java/device/cdPlayer/CDPlayerTest.java b/src/test/java/device/cdPlayer/CDPlayerTest.java
index 3d651ac..43358dd 100644
--- a/src/test/java/device/cdPlayer/CDPlayerTest.java
+++ b/src/test/java/device/cdPlayer/CDPlayerTest.java
@@ -12,7 +12,6 @@ import java.util.stream.Stream;
 
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.junit.jupiter.api.Assertions.*;
-
 @ExtendWith(MockitoExtension.class)
 class CDPlayerTest {
 
@@ -78,11 +77,34 @@ class CDPlayerTest {
         cdPlayer9.tapOnCdFlap();
         cdPlayer9.setCD(audioCD3);
         cdPlayer9.tapOnCdFlap();
+    @ParameterizedTest
+    @MethodSource("louderTestData")
+    void louderTest(String testName,String testDirection, CDPlayer _cdPlayer,int anzClicks, int expectedResult) {
+        for (int i = 0; i < anzClicks; i++) {
+            _cdPlayer.louder();
+        }
+        if(testDirection.equals("VolumeIncreased")){
+            assertThat(_cdPlayer.getVolume()).describedAs(testName).isEqualTo(expectedResult);
+        }
+        if(testDirection.equals("VolumeHasChanged")){
+            assertThat(_cdPlayer.getVolume()).describedAs(testName).isNotEqualTo(expectedResult);
+        }if(testDirection.equals("VolumeNotDecreased")){
+            assertThat(_cdPlayer.getVolume()).describedAs(testName).isNotEqualTo(expectedResult);
+        }
+    }
 
         CDPlayer cdPlayer10=new CDPlayer();
         cdPlayer10.tapOnCdFlap();
         cdPlayer10.setCD(audioCD4);
         cdPlayer10.tapOnCdFlap();
+    static Stream<Arguments> louderTestData () {
+        CDPlayer cdPlayer=new CDPlayer();
+        return Stream.of(
+                Arguments.of("[getVolume() after 20x louder() ] => VolumeIncreased","VolumeIncreased", cdPlayer, 20, 20),
+                Arguments.of("[getVolume() after 2x louder() ] => VolumeHasChanged","VolumeHasChanged" ,cdPlayer,2,0),
+                Arguments.of("[getVolume() after 5x louder() ] => VolumeDecreased","VolumeNotDecreased", cdPlayer,5,-5)
+        );
+    }
 
         return Stream.of(
                 Arguments.of("[CdFlap=isClosed , CdDriveContent=>isEmpty] => NoCD", cdPlayer1, new NoCDException(), "CD must be set."),