diff --git a/src/together/resources/audio/transcriptions.py b/src/together/resources/audio/transcriptions.py
index 766d417..49aea2a 100644
--- a/src/together/resources/audio/transcriptions.py
+++ b/src/together/resources/audio/transcriptions.py
@@ -104,7 +104,12 @@ def create(
             )
 
         # Add any additional kwargs
-        params_data.update(kwargs)
+        # Convert boolean values to lowercase strings for proper form encoding
+        for key, value in kwargs.items():
+            if isinstance(value, bool):
+                params_data[key] = str(value).lower()
+            else:
+                params_data[key] = value
 
         try:
             response, _, _ = requestor.request(
@@ -131,7 +136,8 @@ def create(
             response_format == "verbose_json"
             or response_format == AudioTranscriptionResponseFormat.VERBOSE_JSON
         ):
-            return AudioTranscriptionVerboseResponse(**response.data)
+            # Create response with model validation that preserves extra fields
+            return AudioTranscriptionVerboseResponse.model_validate(response.data)
         else:
             return AudioTranscriptionResponse(**response.data)
 
@@ -234,7 +240,12 @@ async def create(
             )
 
         # Add any additional kwargs
-        params_data.update(kwargs)
+        # Convert boolean values to lowercase strings for proper form encoding
+        for key, value in kwargs.items():
+            if isinstance(value, bool):
+                params_data[key] = str(value).lower()
+            else:
+                params_data[key] = value
 
         try:
             response, _, _ = await requestor.arequest(
@@ -261,6 +272,7 @@ async def create(
             response_format == "verbose_json"
             or response_format == AudioTranscriptionResponseFormat.VERBOSE_JSON
         ):
-            return AudioTranscriptionVerboseResponse(**response.data)
+            # Create response with model validation that preserves extra fields
+            return AudioTranscriptionVerboseResponse.model_validate(response.data)
         else:
             return AudioTranscriptionResponse(**response.data)
diff --git a/src/together/types/audio_speech.py b/src/together/types/audio_speech.py
index b3c110f..bb54cc7 100644
--- a/src/together/types/audio_speech.py
+++ b/src/together/types/audio_speech.py
@@ -158,6 +158,17 @@ class AudioTranscriptionWord(BaseModel):
     word: str
     start: float
     end: float
+    id: Optional[int] = None
+    speaker_id: Optional[str] = None
+
+
+class AudioSpeakerSegment(BaseModel):
+    id: int
+    speaker_id: str
+    start: float
+    end: float
+    text: str
+    words: List[AudioTranscriptionWord]
 
 
 class AudioTranscriptionResponse(BaseModel):
@@ -165,11 +176,13 @@ class AudioTranscriptionResponse(BaseModel):
 
 
 class AudioTranscriptionVerboseResponse(BaseModel):
+    id: Optional[str] = None
     language: Optional[str] = None
     duration: Optional[float] = None
     text: str
     segments: Optional[List[AudioTranscriptionSegment]] = None
     words: Optional[List[AudioTranscriptionWord]] = None
+    speaker_segments: Optional[List[AudioSpeakerSegment]] = None
 
 
 class AudioTranslationResponse(BaseModel):
diff --git a/tests/integration/resources/test_transcriptions.py b/tests/integration/resources/test_transcriptions.py
index 3852ebe..d8afd36 100644
--- a/tests/integration/resources/test_transcriptions.py
+++ b/tests/integration/resources/test_transcriptions.py
@@ -9,6 +9,47 @@
 )
 
 
+def validate_diarization_response(response_dict):
+    """
+    Helper function to validate diarization response structure
+    """
+    # Validate top-level speaker_segments field
+    assert "speaker_segments" in response_dict
+    assert isinstance(response_dict["speaker_segments"], list)
+    assert len(response_dict["speaker_segments"]) > 0
+
+    # Validate each speaker segment structure
+    for segment in response_dict["speaker_segments"]:
+        assert "text" in segment
+        assert "id" in segment
+        assert "speaker_id" in segment
+        assert "start" in segment
+        assert "end" in segment
+        assert "words" in segment
+
+        # Validate nested words in speaker segments
+        assert isinstance(segment["words"], list)
+        for word in segment["words"]:
+            assert "id" in word
+            assert "word" in word
+            assert "start" in word
+            assert "end" in word
+            assert "speaker_id" in word
+
+    # Validate top-level words field
+    assert "words" in response_dict
+    assert isinstance(response_dict["words"], list)
+    assert len(response_dict["words"]) > 0
+
+    # Validate each word in top-level words
+    for word in response_dict["words"]:
+        assert "id" in word
+        assert "word" in word
+        assert "start" in word
+        assert "end" in word
+        assert "speaker_id" in word
+
+
 class TestTogetherTranscriptions:
     @pytest.fixture
     def sync_together_client(self) -> Together:
@@ -116,3 +157,96 @@ def test_language_detection_hindi(self, sync_together_client):
         assert len(response.text) > 0
         assert hasattr(response, "language")
         assert response.language == "hi"
+
+    def test_diarization_default(self, sync_together_client):
+        """
+        Test diarization with default model in verbose JSON format
+        """
+        audio_url = "https://together-public-test-data.s3.us-west-2.amazonaws.com/audio/2-speaker-conversation.wav"
+
+        response = sync_together_client.audio.transcriptions.create(
+            file=audio_url,
+            model="openai/whisper-large-v3",
+            response_format="verbose_json",
+            diarize=True,
+        )
+
+        assert isinstance(response, AudioTranscriptionVerboseResponse)
+        assert isinstance(response.text, str)
+        assert len(response.text) > 0
+
+        # Validate diarization fields
+        response_dict = response.model_dump()
+        validate_diarization_response(response_dict)
+
+    def test_diarization_nvidia(self, sync_together_client):
+        """
+        Test diarization with nvidia model in verbose JSON format
+        """
+        audio_url = "https://together-public-test-data.s3.us-west-2.amazonaws.com/audio/2-speaker-conversation.wav"
+
+        response = sync_together_client.audio.transcriptions.create(
+            file=audio_url,
+            model="openai/whisper-large-v3",
+            response_format="verbose_json",
+            diarize=True,
+            diarization_model="nvidia",
+        )
+
+        assert isinstance(response, AudioTranscriptionVerboseResponse)
+        assert isinstance(response.text, str)
+        assert len(response.text) > 0
+
+        # Validate diarization fields
+        response_dict = response.model_dump()
+        validate_diarization_response(response_dict)
+
+    def test_diarization_pyannote(self, sync_together_client):
+        """
+        Test diarization with pyannote model in verbose JSON format
+        """
+        audio_url = "https://together-public-test-data.s3.us-west-2.amazonaws.com/audio/2-speaker-conversation.wav"
+
+        response = sync_together_client.audio.transcriptions.create(
+            file=audio_url,
+            model="openai/whisper-large-v3",
+            response_format="verbose_json",
+            diarize=True,
+            diarization_model="pyannote",
+        )
+
+        assert isinstance(response, AudioTranscriptionVerboseResponse)
+        assert isinstance(response.text, str)
+        assert len(response.text) > 0
+
+        # Validate diarization fields
+        response_dict = response.model_dump()
+        validate_diarization_response(response_dict)
+
+    def test_no_diarization(self, sync_together_client):
+        """
+        Test with diarize=false should not have speaker segments
+        """
+        audio_url = "https://together-public-test-data.s3.us-west-2.amazonaws.com/audio/2-speaker-conversation.wav"
+
+        response = sync_together_client.audio.transcriptions.create(
+            file=audio_url,
+            model="openai/whisper-large-v3",
+            response_format="verbose_json",
+            diarize=False,
+        )
+
+        assert isinstance(response, AudioTranscriptionVerboseResponse)
+        assert isinstance(response.text, str)
+        assert len(response.text) > 0
+
+        # Verify no diarization fields
+        response_dict = response.model_dump()
+        assert response_dict.get("speaker_segments") is None
+        assert response_dict.get("words") is None
+
+        # Should still have standard fields
+        assert "text" in response_dict
+        assert "language" in response_dict
+        assert "duration" in response_dict
+        assert "segments" in response_dict