diff --git a/audio/6.0/IStreamOut.hal b/audio/6.0/IStreamOut.hal
index 13a86ec..9da48fe 100644
--- a/audio/6.0/IStreamOut.hal
+++ b/audio/6.0/IStreamOut.hal
@@ -19,6 +19,7 @@
 import android.hardware.audio.common@6.0;
 import IStream;
 import IStreamOutCallback;
+import IStreamOutEventCallback;
 
 interface IStreamOut extends IStream {
     /**
@@ -168,6 +169,18 @@
     clearCallback() generates (Result retval);
 
     /**
+     * Set the callback interface for notifying about an output stream event.
+     *
+     * Calling this method with a null pointer will result in releasing
+     * the local callback proxy on the server side and thus dereference
+     * the callback implementation on the client side.
+     *
+     * @return retval operation completion status.
+     */
+    setEventCallback(IStreamOutEventCallback callback)
+            generates (Result retval);
+
+    /**
      * Returns whether HAL supports pausing and resuming of streams.
      *
      * @return supportsPause true if pausing is supported.