diff --git a/rtcllm/a2a.py b/rtcllm/a2a.py
index a25f1d3..184824a 100644
--- a/rtcllm/a2a.py
+++ b/rtcllm/a2a.py
@@ -1,4 +1,5 @@
 import io
+import asyncio
 from av import AudioFrame
 
 from aiortc import VideoStreamTrack, AudioStreamTrack
@@ -18,6 +19,7 @@ class LLMAudioStreamTrack(AudioStreamTrack):
 				print('LLMAudioStreamTrack return None ...')
 				return b
 			frame = AudioFrame.from_ndarray(io.BytesIO(b), format='s16', layout='mono')
+			print('LLMAudioStreamTrack return frame ...')
 			return frame
 		except Exception as e:
 			print_exc()