diff --git a/tts/tts_audio_handle.py b/tts/tts_audio_handle.py
index 25d130a..b64ca95 100644
--- a/tts/tts_audio_handle.py
+++ b/tts/tts_audio_handle.py
@@ -3,6 +3,7 @@ import heapq
 import logging
 import os
 import shutil
+from threading import Lock
 
 from eventbus import EventBus
 from utils import save_wav
@@ -28,7 +29,7 @@ class TTSAudioHandle(AudioHandler):
         self.stop()
 
     def on_clear_cache(self, *args, **kwargs):
-        pass
+        self._index = -1
 
     @property
     def sample_rate(self):
@@ -58,6 +59,7 @@ class TTSAudioSplitHandle(TTSAudioHandle):
         self.sample_rate = self._context.sample_rate
         self._chunk = self.sample_rate // self._context.fps
         self._priority_queue = []
+        self._lock = Lock()
         self._current = 0
         self._is_running = True
         logger.info("TTSAudioSplitHandle init")
@@ -81,26 +83,35 @@ class TTSAudioSplitHandle(TTSAudioHandle):
             if not self._is_running:
                 return
             heapq.heappush(self._priority_queue, (index, chunks))
-        current = self._priority_queue[0][0]
-        print('TTSAudioSplitHandle::on_handle', index, current, self._current, len(self._priority_queue))
-        if current == self._current:
-            self._current = self._current + 1
-            chunks = heapq.heappop(self._priority_queue)[1]
-            if chunks is None:
-                pass
-            else:
-                for chunk in chunks:
-                    self.on_next_handle(chunk, 0)
+
+        with self._lock:
+            current = self._priority_queue[0][0]
+            if current == 0:
+                self._current = 0
+            print('TTSAudioSplitHandle::on_handle', index, current, self._current, len(self._priority_queue))
+            if current == self._current:
+                self._current = self._current + 1
+                chunks = heapq.heappop(self._priority_queue)[1]
+                if chunks is None:
+                    pass
+                else:
+                    for chunk in chunks:
+                        self.on_next_handle(chunk, 0)
 
     def stop(self):
         self._is_running = False
 
     def on_clear_cache(self, *args, **kwargs):
+        super().on_clear_cache()
         if self._priority_queue is None or len(self._priority_queue) == 0:
             return
-        current = self._priority_queue[0][0]
+
+        with self._lock:
+            print('TTSAudioSplitHandle::on_clear_cache', self._current)
+            self._current = 0
+            print('TTSAudioSplitHandle::on_clear_cache', self._current)
+
         self._priority_queue.clear()
-        self._current = current
 
 
 class TTSAudioSaveHandle(TTSAudioHandle):