diff --git a/rtcllm/a2a.py b/rtcllm/a2a.py
index fcfebce..a25f1d3 100644
--- a/rtcllm/a2a.py
+++ b/rtcllm/a2a.py
@@ -15,13 +15,14 @@ class LLMAudioStreamTrack(AudioStreamTrack):
 		try:
 			b = self.get_audio_bytes()
 			if b is None:
+				print('LLMAudioStreamTrack return None ...')
 				return b
 			frame = AudioFrame.from_ndarray(io.BytesIO(b), format='s16', layout='mono')
 			return frame
 		except Exception as e:
 			print_exc()
 			print(f'{self.__class__.__name__} recv() exception happened')
-			raise e
+			return None
 
 	def set_cur_audio_iter(self):
 		if len(self.audio_iters) == 0: