diff --git a/audio/CMakeLists.txt b/audio/CMakeLists.txt
index 6103dad43e0..de1e545705d 100644
--- a/audio/CMakeLists.txt
+++ b/audio/CMakeLists.txt
@@ -1,6 +1,8 @@
 # ##############################################################################
 # audio/CMakeLists.txt
 #
+# SPDX-License-Identifier: Apache-2.0
+#
 # Licensed to the Apache Software Foundation (ASF) under one or more contributor
 # license agreements.  See the NOTICE file distributed with this work for
 # additional information regarding copyright ownership.  The ASF licenses this
diff --git a/audio/Makefile b/audio/Makefile
index 94df7baae7c..d3b50e96f73 100644
--- a/audio/Makefile
+++ b/audio/Makefile
@@ -1,6 +1,8 @@
 ############################################################################
 # audio/Makefile
 #
+# SPDX-License-Identifier: Apache-2.0
+#
 # Licensed to the Apache Software Foundation (ASF) under one or more
 # contributor license agreements.  See the NOTICE file distributed with
 # this work for additional information regarding copyright ownership.  The
diff --git a/audio/audio.c b/audio/audio.c
index 3bc906e9836..f521375decb 100644
--- a/audio/audio.c
+++ b/audio/audio.c
@@ -1,6 +1,8 @@
 /****************************************************************************
  * audio/audio.c
  *
+ * SPDX-License-Identifier: Apache-2.0
+ *
  * Licensed to the Apache Software Foundation (ASF) under one or more
  * contributor license agreements.  See the NOTICE file distributed with
  * this work for additional information regarding copyright ownership.  The
diff --git a/audio/audio_comp.c b/audio/audio_comp.c
index d9957da3131..82300e7dd52 100644
--- a/audio/audio_comp.c
+++ b/audio/audio_comp.c
@@ -1,6 +1,8 @@
 /****************************************************************************
  * audio/audio_comp.c
  *
+ * SPDX-License-Identifier: Apache-2.0
+ *
  * Licensed to the Apache Software Foundation (ASF) under one or more
  * contributor license agreements.  See the NOTICE file distributed with
  * this work for additional information regarding copyright ownership.  The
diff --git a/audio/pcm_decode.c b/audio/pcm_decode.c
index 60c8b9af4d9..fbd618b9082 100644
--- a/audio/pcm_decode.c
+++ b/audio/pcm_decode.c
@@ -1,6 +1,8 @@
 /****************************************************************************
  * audio/pcm_decode.c
  *
+ * SPDX-License-Identifier: Apache-2.0
+ *
  * Licensed to the Apache Software Foundation (ASF) under one or more
  * contributor license agreements.  See the NOTICE file distributed with
  * this work for additional information regarding copyright ownership.  The