feat: Add option to ignore emulated user speech while the bot is speaking

CHANGELOG.md

@@ -9,6 +9,12 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Added
 
+- Added `enable_emulated_vad_interruptions` to `LLMUserAggregatorParams`.
+  When user speech is emulated (e.g. when a transcription is received but
+  VAD doesn't detect speech), this parameter controls whether the emulated
+  speech can interrupt the bot. Default is False (emulated speech is ignored
+  while the bot is speaking).
+
 - Added new `handle_sigint` and `handle_sigterm` to `RunnerArguments`. This
   allows applications to know what settings they should use for the environment
   they are running on. Also, added `pipeline_idle_timeout_secs` to be able to

src/pipecat/processors/aggregators/llm_response.py

@@ -73,10 +73,14 @@ class LLMUserAggregatorParams:
         turn_emulated_vad_timeout: Maximum time in seconds to wait for emulated
             VAD when using turn-based analysis. Applied when transcription is
             received but VAD didn't detect speech (e.g., whispered utterances).
+        enable_emulated_vad_interruptions: When True, allows emulated VAD events
+            to interrupt the bot when it's speaking. When False, emulated speech
+            is ignored while the bot is speaking.
     """
 
     aggregation_timeout: float = 0.5
     turn_emulated_vad_timeout: float = 0.8
+    enable_emulated_vad_interruptions: bool = False
 
 
 @dataclass
@@ -686,26 +690,24 @@ class LLMUserContextAggregator(LLMContextResponseAggregator):
         """Maybe emulate user speaking based on transcription.
 
         Emulate user speaking if we got a transcription but it was not
-        detected by VAD. Only do that if the bot is not speaking.
+        detected by VAD. Behavior when bot is speaking depends on the
+        enable_emulated_vad_interruptions parameter.
         """
         # Check if we received a transcription but VAD was not able to detect
         # voice (e.g. when you whisper a short utterance). In that case, we need
-        # to emulate VAD (i.e. user start/stopped speaking), but we do it only
-        # if the bot is not speaking. If the bot is speaking and we really have
-        # a short utterance we don't really want to interrupt the bot.
+        # to emulate VAD (i.e. user start/stopped speaking).
         if (
             not self._user_speaking
             and not self._waiting_for_aggregation
             and len(self._aggregation) > 0
         ):
-            if self._bot_speaking:
-                # If we reached this case and the bot is speaking, let's ignore
-                # what the user said.
+            if self._bot_speaking and not self._params.enable_emulated_vad_interruptions:
+                # If emulated VAD interruptions are disabled and bot is speaking, ignore
                 logger.debug("Ignoring user speaking emulation, bot is speaking.")
                 await self.reset()
             else:
-                # The bot is not speaking so, let's trigger user speaking
-                # emulation.
+                # Either bot is not speaking, or emulated VAD interruptions are enabled
+                # - trigger user speaking emulation.
                 await self.push_frame(EmulateUserStartedSpeakingFrame(), FrameDirection.UPSTREAM)
                 self._emulating_vad = True