diff --git a/include/hardware/audio.h b/include/hardware/audio.h
index bf6e90a..878b1b2 100644
--- a/include/hardware/audio.h
+++ b/include/hardware/audio.h
@@ -41,6 +41,17 @@
  */
 #define AUDIO_HARDWARE_INTERFACE "audio_hw_if"
 
+/**
+ * List of known audio HAL modules. This is the base name of the audio HAL
+ * library composed of the "audio." prefix, one of the base names below and
+ * a suffix specific to the device.
+ * e.g: audio.primary.goldfish.so or audio.a2dp.default.so
+ */
+
+#define AUDIO_HARDWARE_MODULE_ID_PRIMARY "primary"
+#define AUDIO_HARDWARE_MODULE_ID_A2DP "a2dp"
+#define AUDIO_HARDWARE_MODULE_ID_USB "usb"
+
 /**************************************/
 
 /**