diff --git a/module_usb_audio/audiostream/audiostream.c b/module_usb_audio/audiostream/audiostream.c
new file mode 100644
index 00000000..90436307
--- /dev/null
+++ b/module_usb_audio/audiostream/audiostream.c
@@ -0,0 +1,13 @@
+
+/* Deafult implementations of AudioStreamStop() and AudioStreamStart().  Both can be over-ridden */
+void UserAudioStreamStop() __attribute__ ((weak));
+void UserAudioStreamStop()
+{
+    return;
+}  
+
+void UserAudioStreamStart() __attribute__ ((weak));
+void UserAudioStreamStart()
+{
+    return;
+}
diff --git a/module_usb_audio/hostactive/hostactive.c b/module_usb_audio/hostactive/hostactive.c
new file mode 100644
index 00000000..b8bd33ec
--- /dev/null
+++ b/module_usb_audio/hostactive/hostactive.c
@@ -0,0 +1,7 @@
+
+void UserHostActive(int active) __attribute__ ((weak));
+void UserHostActive(int active)
+{
+    return;
+}
+