diff --git a/include/hardware/bt_av.h b/include/hardware/bt_av.h
index 428a5b1..9b32216 100644
--- a/include/hardware/bt_av.h
+++ b/include/hardware/bt_av.h
@@ -98,7 +98,10 @@
     void  (*cleanup)( void );
 
     /** Sends Audio Focus State. */
-    void  (*audio_focus_state)( int focus_state );
+    void  (*set_audio_focus_state)( int focus_state );
+
+    /** Sets the audio track gain. */
+    void  (*set_audio_track_gain)( float gain );
 } btav_interface_t;
 
 __END_DECLS