diff --git a/modules/audio/proto/audio_common.proto b/modules/audio/proto/audio_common.proto
index a017a1e6bf65f09b594fbbef75cb939a87a2d84e..e265e9a6edc6a2ea68f3dca6a2166ee82dc4c25b 100644
--- a/modules/audio/proto/audio_common.proto
+++ b/modules/audio/proto/audio_common.proto
@@ -24,3 +24,18 @@ enum MovingResult {
   DEPARTING = 2;
   STATIONARY = 3;
 }
+
+enum AudioType {
+  UNKNOWN_TYPE = 0;
+  POLICE = 1;
+  AMBULANCE = 2;
+  FIRETRUCK = 3;
+}
+
+enum AudioDirection {
+  UNKNOWN_DIRECTION = 0;
+  FRONT = 1;
+  LEFT = 2;
+  BACK = 3;
+  RIGHT = 4;
+}
diff --git a/modules/audio/proto/audio_event.proto b/modules/audio/proto/audio_event.proto
index 2b491c651c47e17801a02bbbbb6957d7d0efa982..ae7e821795c52b5a08326d6e6a17df6c5ab0935f 100644
--- a/modules/audio/proto/audio_event.proto
+++ b/modules/audio/proto/audio_event.proto
@@ -9,5 +9,7 @@ message AudioEvent {
   optional apollo.common.Header header = 1;
   optional int32 id = 2;  // obstacle ID.
   optional apollo.audio.MovingResult moving_result = 3 [default = UNKNOWN];
-  optional bool siren_is_on = 4;
+  optional apollo.audio.AudioType audio_type = 4 [default = UNKNOWN_TYPE];
+  optional bool siren_is_on = 5;
+  optional apollo.audio.AudioDirection audio_direction = 6 [default = UNKNOWN_DIRECTION];
 }