diff --git a/include/media/ToneGenerator.h b/include/media/ToneGenerator.h
index ea6bf5d..e8df08e 100644
--- a/include/media/ToneGenerator.h
+++ b/include/media/ToneGenerator.h
@@ -167,7 +167,8 @@
         TONE_STARTING,  // ToneGenerator is starting playing
         TONE_PLAYING,  // ToneGenerator is playing
         TONE_STOPPING,  // ToneGenerator is stoping
-        TONE_RESTARTING  //
+        TONE_STOPPED,  // ToneGenerator is stopped: the AudioTrack will be stopped
+        TONE_RESTARTING  // A start request was received in active state (playing or stopping)
     };