diff --git a/include/hardware/audio.h b/include/hardware/audio.h
index 763ca58..8d5b2f0 100644
--- a/include/hardware/audio.h
+++ b/include/hardware/audio.h
@@ -112,6 +112,10 @@
 /* Bluetooth SCO wideband */
 #define AUDIO_PARAMETER_KEY_BT_SCO_WB "bt_wbs"
 
+/* Get a new HW synchronization source identifier.
+ * Return a valid source (positive integer) or AUDIO_HW_SYNC_INVALID if an error occurs
+ * or no HW sync is available. */
+#define AUDIO_PARAMETER_HW_AV_SYNC "hw_av_sync"
 
 /**
  *  audio stream parameters
@@ -136,9 +140,7 @@
  * "sup_sampling_rates=44100|48000" */
 #define AUDIO_PARAMETER_STREAM_SUP_SAMPLING_RATES "sup_sampling_rates"
 
-/* Get the HW synchronization source used for an output stream.
- * Return a valid source (positive integer) or AUDIO_HW_SYNC_INVALID if an error occurs
- * or no HW sync source is used. */
+/* Set the HW synchronization source for an output stream. */
 #define AUDIO_PARAMETER_STREAM_HW_AV_SYNC "hw_av_sync"
 
 /**