diff --git a/include/media/AudioSystem.h b/include/media/AudioSystem.h
index f22792f..dd63a23 100644
--- a/include/media/AudioSystem.h
+++ b/include/media/AudioSystem.h
@@ -149,6 +149,11 @@
     static void acquireAudioSessionId(int audioSession, pid_t pid);
     static void releaseAudioSessionId(int audioSession, pid_t pid);
 
+    // Get the HW synchronization source used for an audio session.
+    // Return a valid source or AUDIO_HW_SYNC_INVALID if an error occurs
+    // or no HW sync source is used.
+    static audio_hw_sync_t getAudioHwSyncForSession(audio_session_t sessionId);
+
     // types of io configuration change events received with ioConfigChanged()
     enum io_config_event {
         OUTPUT_OPENED,