diff --git a/CHANGELOG.md b/CHANGELOG.md
index 5448399d7..e81db88a2 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -12,6 +12,15 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Added support for a new TTS service, `PiperTTSService`.
   (see https://github.com/rhasspy/piper/)
 
+- It is now possible to tell whether `UserStartedSpeakingFrame` or
+  `UserStoppedSpeakingFrame` have been generated because of emulation frames.
+
+### Fixed
+
+- Fixed an issue that would cause `SegmentedSTTService` based services
+  (e.g. `OpenAISTTService`) to try to transcribe non-spoken audio, causing
+  invalid transcriptions.
+
 ## [0.0.61] - 2025-03-26
 
 ### Added
@@ -28,9 +37,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 - ElevenLabs TTS services now support a sample rate of 8000.
 
-- Added support for `instructions` in `OpenAITTSService`
+- Added support for `instructions` in `OpenAITTSService`.
 
-- Added support for `base_url` in `OpenAIImageGenService` and `OpenAITTSService`
+- Added support for `base_url` in `OpenAIImageGenService` and
+  `OpenAITTSService`.
 
 ### Fixed
 
diff --git a/src/pipecat/frames/frames.py b/src/pipecat/frames/frames.py
index 11cd17801..30d8622d9 100644
--- a/src/pipecat/frames/frames.py
+++ b/src/pipecat/frames/frames.py
@@ -562,14 +562,14 @@ class UserStartedSpeakingFrame(SystemFrame):
 
     """
 
-    pass
+    emulated: bool = False
 
 
 @dataclass
 class UserStoppedSpeakingFrame(SystemFrame):
     """Emitted by the VAD to indicate that a user stopped speaking."""
 
-    pass
+    emulated: bool = False
 
 
 @dataclass
diff --git a/src/pipecat/processors/aggregators/llm_response.py b/src/pipecat/processors/aggregators/llm_response.py
index af8bf1a2e..e40ad266b 100644
--- a/src/pipecat/processors/aggregators/llm_response.py
+++ b/src/pipecat/processors/aggregators/llm_response.py
@@ -249,7 +249,7 @@ class LLMUserContextAggregator(LLMContextResponseAggregator):
         self._waiting_for_aggregation = False
 
     async def handle_aggregation(self, aggregation: str):
-        self._context.add_message({"role": self.role, "content": self._aggregation})
+        self._context.add_message({"role": self.role, "content": aggregation})
 
     async def process_frame(self, frame: Frame, direction: FrameDirection):
         await super().process_frame(frame, direction)
@@ -290,12 +290,14 @@ class LLMUserContextAggregator(LLMContextResponseAggregator):
 
     async def push_aggregation(self):
         if len(self._aggregation) > 0:
-            await self.handle_aggregation(self._aggregation)
+            aggregation = self._aggregation
 
             # Reset the aggregation. Reset it before pushing it down, otherwise
             # if the tasks gets cancelled we won't be able to clear things up.
             self.reset()
 
+            await self.handle_aggregation(aggregation)
+
             frame = OpenAILLMContextFrame(self._context)
             await self.push_frame(frame)
 
@@ -308,10 +310,16 @@ class LLMUserContextAggregator(LLMContextResponseAggregator):
     async def _cancel(self, frame: CancelFrame):
         await self._cancel_aggregation_task()
 
-    async def _handle_user_started_speaking(self, _: UserStartedSpeakingFrame):
+    async def _handle_user_started_speaking(self, frame: UserStartedSpeakingFrame):
         self._user_speaking = True
         self._waiting_for_aggregation = True
 
+        # If we get a non-emulated UserStartedSpeakingFrame but we are in the
+        # middle of emulating VAD, let's stop emulating VAD (i.e. don't send the
+        # EmulateUserStoppedSpeakingFrame).
+        if not frame.emulated and self._emulating_vad:
+            self._emulating_vad = False
+
     async def _handle_user_stopped_speaking(self, _: UserStoppedSpeakingFrame):
         self._user_speaking = False
         # We just stopped speaking. Let's see if there's some aggregation to
diff --git a/src/pipecat/services/ai_services.py b/src/pipecat/services/ai_services.py
index a78c268dd..97aad0d40 100644
--- a/src/pipecat/services/ai_services.py
+++ b/src/pipecat/services/ai_services.py
@@ -1048,9 +1048,14 @@ class SegmentedSTTService(STTService):
             await self._handle_user_stopped_speaking(frame)
 
     async def _handle_user_started_speaking(self, frame: UserStartedSpeakingFrame):
+        if frame.emulated:
+            return
         self._user_speaking = True
 
     async def _handle_user_stopped_speaking(self, frame: UserStoppedSpeakingFrame):
+        if frame.emulated:
+            return
+
         self._user_speaking = False
 
         content = io.BytesIO()
@@ -1068,7 +1073,7 @@ class SegmentedSTTService(STTService):
         self._audio_buffer.clear()
 
     async def process_audio_frame(self, frame: AudioRawFrame, direction: FrameDirection):
-        # If the user is speaking the audio buffer will keep growin.
+        # If the user is speaking the audio buffer will keep growing.
         self._audio_buffer += frame.audio
 
         # If the user is not speaking we keep just a little bit of audio.
diff --git a/src/pipecat/transports/base_input.py b/src/pipecat/transports/base_input.py
index 971dfe066..26f386576 100644
--- a/src/pipecat/transports/base_input.py
+++ b/src/pipecat/transports/base_input.py
@@ -117,10 +117,10 @@ class BaseInputTransport(FrameProcessor):
             await self._handle_bot_interruption(frame)
         elif isinstance(frame, EmulateUserStartedSpeakingFrame):
             logger.debug("Emulating user started speaking")
-            await self._handle_user_interruption(UserStartedSpeakingFrame())
+            await self._handle_user_interruption(UserStartedSpeakingFrame(emulated=True))
         elif isinstance(frame, EmulateUserStoppedSpeakingFrame):
             logger.debug("Emulating user stopped speaking")
-            await self._handle_user_interruption(UserStoppedSpeakingFrame())
+            await self._handle_user_interruption(UserStoppedSpeakingFrame(emulated=True))
         # All other system frames
         elif isinstance(frame, SystemFrame):
             await self.push_frame(frame, direction)