correct variable issue

app.py

@@ -885,6 +885,7 @@ def playsound1():
             soundfilename = Filename_Chatbot
             print("soundfilename:", soundfilename)
             # return None
+            Filename_Chatbot = ""
             return gr.update(value = soundfilename)
             # return soundfilename
             # yield soundfilename
@@ -944,6 +945,7 @@ last_answer = ""
 
 def SingleTalk(WavFile, history5):
     global last_answer
+    global Filename_Chatbot
     ConvertText = speech_to_text(WavFile)
     history5 = history5 + [(ConvertText, None)]
     yield [None, None, history5]