diff --git a/packages/services/voice-agent/src/plugins/speechmatics_stt.py b/packages/services/voice-agent/src/plugins/speechmatics_stt.py
index b9a5aef..80785c2 100644
--- a/packages/services/voice-agent/src/plugins/speechmatics_stt.py
+++ b/packages/services/voice-agent/src/plugins/speechmatics_stt.py
@@ -39,6 +39,8 @@ def _patched_handle_partial_segment(self: SpeechStream, message: dict) -> None:
     """Intercept partial segments and stash them for flush-time promotion."""
     segments = message.get("segments", [])
     if segments:
+        text = " | ".join(s.get("text", "") for s in segments)
+        logger.info("[SM-PATCH] stashing %d partial segment(s): %s", len(segments), text[:100])
         self._sm_last_partial_segments = segments  # type: ignore[attr-defined]
     _original_handle_partial_segment(self, message)
 
@@ -47,35 +49,41 @@ _original_process_audio = SpeechStream._process_audio
 
 
 async def _patched_process_audio(self: SpeechStream) -> None:  # type: ignore[override]
+    logger.info("[SM-PATCH] _patched_process_audio STARTED")
     self._sm_last_partial_segments: list = []  # type: ignore[attr-defined]
     try:
         audio_bstream = utils.audio.AudioByteStream(
             sample_rate=self._stt._sample_rate,
             num_channels=1,
         )
+        frame_count = 0
         async for data in self._input_ch:
             if isinstance(data, self._FlushSentinel):
+                logger.info("[SM-PATCH] FlushSentinel received (after %d frames)", frame_count)
                 frames = audio_bstream.flush()
                 # Promote stored partials → FINAL_TRANSCRIPT immediately
                 stored = getattr(self, "_sm_last_partial_segments", [])
                 if stored:
                     logger.info(
-                        "FlushSentinel: promoting %d partial segment(s) to FINAL",
+                        "[SM-PATCH] promoting %d partial segment(s) to FINAL",
                         len(stored),
                     )
                     self._send_frames(stored, is_final=True)
                     self._sm_last_partial_segments = []  # type: ignore[attr-defined]
                 else:
-                    logger.warning("FlushSentinel received but no partial segments stored")
+                    logger.warning("[SM-PATCH] FlushSentinel but no partial segments stored")
             else:
                 frames = audio_bstream.write(data.data.tobytes())
+                frame_count += 1
 
             if self._client:
                 for frame in frames:
                     self._speech_duration += frame.duration
                     await self._client.send_audio(frame.data.tobytes())
     except asyncio.CancelledError:
-        pass
+        logger.info("[SM-PATCH] _patched_process_audio cancelled (processed %d frames)", frame_count if 'frame_count' in dir() else -1)
+    except Exception as e:
+        logger.error("[SM-PATCH] _patched_process_audio ERROR: %s", e, exc_info=True)
 
 
 SpeechStream._process_audio = _patched_process_audio  # type: ignore[assignment]