diff -r 000000000000 -r bde4ae8d615e os/mm/devsoundextensions/effects/Loudness/LoudnessProxy/Src/MLoudnessCallback.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/os/mm/devsoundextensions/effects/Loudness/LoudnessProxy/Src/MLoudnessCallback.h	Fri Jun 15 03:10:57 2012 +0200
@@ -0,0 +1,50 @@
+/*
+* Copyright (c) 2004 Nokia Corporation and/or its subsidiary(-ies). 
+* All rights reserved.
+* This component and the accompanying materials are made available
+* under the terms of "Eclipse Public License v1.0"
+* which accompanies this distribution, and is available
+* at the URL "http://www.eclipse.org/legal/epl-v10.html".
+*
+* Initial Contributors:
+* Nokia Corporation - initial contribution.
+*
+* Contributors:
+*
+* Description:  Interface for loudness call back 
+*
+*/
+
+
+
+
+#ifndef MLOUDNESSCALLBACK_H
+#define MLOUDNESSCALLBACK_H
+
+//  INCLUDES
+
+// CLASS DECLARATION
+
+
+/**
+*  Interface class to be implemented by objects that receives callbacks from Loudness Event Observer.
+*
+*  @since 3.0
+*/
+class MLoudnessCallback
+    {
+    public:
+
+        /**
+        * Invoked by the Loudness Event Observer when the Loudness object changes state
+        * @since 3.0
+        * @param aBuffer Buffer containing the loudness data
+        */
+        virtual void LoudnessEvent( TDesC8& aDataPckg ) = 0;
+    };
+
+
+
+#endif      // MLOUDNESSCALLBACK_H
+
+// End of File