diff --git a/platypush/message/event/assistant/__init__.py b/platypush/message/event/assistant/__init__.py
index 7facd40e..79ab7cf0 100644
--- a/platypush/message/event/assistant/__init__.py
+++ b/platypush/message/event/assistant/__init__.py
@@ -22,7 +22,7 @@ class AssistantEvent(Event):
                 self._assistant = get_plugin('assistant.google.pushtotalk')
 
             if not self._assistant:
-                logger.warning('google.assistant not configured/initialized')
+                logger.warning('Assistant plugin/backend not configured/initialized')
                 self._assistant = None
 
 class ConversationStartEvent(AssistantEvent):
@@ -85,13 +85,13 @@ class SpeechRecognizedEvent(AssistantEvent):
     Event triggered when a speech is recognized
     """
 
-    def __init__(self, phrase, *args, assistant=None, **kwargs):
+    def __init__(self, phrase, *args, **kwargs):
         """
         :param phrase: Recognized user phrase
         :type phrase: str
         """
 
-        super().__init__(*args, phrase=phrase, assistant=assistant, **kwargs)
+        super().__init__(*args, phrase=phrase, **kwargs)
         self.recognized_phrase = phrase.strip().lower()
 
         if not self._assistant and assistant:
@@ -106,9 +106,7 @@ class SpeechRecognizedEvent(AssistantEvent):
         result = super().matches_condition(condition)
 
         if result.is_match and self._assistant and 'phrase' in condition.args:
-            if hasattr(self._assistant, 'play_response'):
-                self._assistant.play_response = False
-            elif hasattr(self._assistant, 'stop_conversation'):
+            if self._assistant:
                 self._assistant.stop_conversation()
 
         return result
diff --git a/platypush/plugins/assistant/google/lib/__init__.py b/platypush/plugins/assistant/google/lib/__init__.py
index 02225944..6c31bb15 100644
--- a/platypush/plugins/assistant/google/lib/__init__.py
+++ b/platypush/plugins/assistant/google/lib/__init__.py
@@ -115,6 +115,7 @@ class SampleAssistant(object):
         if self.on_conversation_start:
             self.on_conversation_start()
 
+        self.play_response = True
         logging.info('Recording audio request.')
 
         def iter_log_assist_requests():
@@ -132,7 +133,6 @@ class SampleAssistant(object):
                 logging.info('End of audio request detected.')
                 logging.info('Stopping recording.')
                 self.conversation_stream.stop_recording()
-                self.play_response = True
 
                 if self.detected_speech and self.on_speech_recognized:
                     self.on_speech_recognized(self.detected_speech)
@@ -151,8 +151,10 @@ class SampleAssistant(object):
                         self.conversation_stream.start_playback()
                         logging.info('Playing assistant response.')
 
-                if self.play_response:
+                if self.play_response and self.conversation_stream.playing:
                     self.conversation_stream.write(resp.audio_out.audio_data)
+                elif self.conversation_stream.playing:
+                    self.conversation_stream.stop_playback()
             if resp.dialog_state_out.conversation_state:
                 conversation_state = resp.dialog_state_out.conversation_state
                 logging.debug('Updating conversation state.')
diff --git a/platypush/plugins/assistant/google/pushtotalk.py b/platypush/plugins/assistant/google/pushtotalk.py
index 702b2574..ffe8eecc 100644
--- a/platypush/plugins/assistant/google/pushtotalk.py
+++ b/platypush/plugins/assistant/google/pushtotalk.py
@@ -146,21 +146,21 @@ class AssistantGooglePushtotalkPlugin(AssistantPlugin):
     def on_conversation_start(self):
         """ Conversation start handler """
         def handler():
-            get_bus().post(ConversationStartEvent(assistant=self.assistant))
+            get_bus().post(ConversationStartEvent())
 
         return handler
 
     def on_conversation_end(self):
         """ Conversation end handler """
         def handler(with_follow_on_turn):
-            get_bus().post(ConversationEndEvent(with_follow_on_turn=with_follow_on_turn, assistant=self.assistant))
+            get_bus().post(ConversationEndEvent(with_follow_on_turn=with_follow_on_turn))
 
         return handler
 
     def on_speech_recognized(self):
         """ Speech recognized handler """
         def handler(phrase):
-            get_bus().post(SpeechRecognizedEvent(phrase=phrase, assistant=self.assistant))
+            get_bus().post(SpeechRecognizedEvent(phrase=phrase))
             self.interactions.append({'request': phrase})
 
         return handler
@@ -168,14 +168,14 @@ class AssistantGooglePushtotalkPlugin(AssistantPlugin):
     def on_volume_changed(self):
         """ Volume changed event """
         def handler(volume):
-            get_bus().post(VolumeChangedEvent(volume=volume, assistant=self.assistant))
+            get_bus().post(VolumeChangedEvent(volume=volume))
 
         return handler
 
     def on_response(self):
         """ Response handler """
         def handler(response):
-            get_bus().post(ResponseEvent(response_text=response, assistant=self.assistant))
+            get_bus().post(ResponseEvent(response_text=response))
 
             if not self.interactions:
                 self.interactions.append({'response': response})
@@ -243,8 +243,13 @@ class AssistantGooglePushtotalkPlugin(AssistantPlugin):
     def stop_conversation(self):
         """ Stop a conversation """
         if self.assistant:
-            self.conversation_stream.stop_playback()
-            get_bus().post(ConversationEndEvent(assistant=self.assistant))
+            self.assistant.play_response = False
+
+            if self.conversation_stream:
+                self.conversation_stream.stop_playback()
+                self.conversation_stream.stop_recording()
+
+            get_bus().post(ConversationEndEvent())
 
 
 # vim:sw=4:ts=4:et: