diff --git a/examples/foundational/12c-describe-video-anthropic.py b/examples/foundational/12c-describe-video-anthropic.py
index 7458adf69..c7267467a 100644
--- a/examples/foundational/12c-describe-video-anthropic.py
+++ b/examples/foundational/12c-describe-video-anthropic.py
@@ -78,7 +78,9 @@ async def main():
         tts = CartesiaTTSService(
             api_key=os.getenv("CARTESIA_API_KEY"),
             voice_id="79a125e8-cd45-4c13-8a67-188112f4dd22",  # British Lady
-            sample_rate=16000,
+            params=CartesiaTTSService.InputParams(
+                sample_rate=16000,
+            ),
         )
 
         @transport.event_handler("on_first_participant_joined")
diff --git a/examples/studypal/studypal.py b/examples/studypal/studypal.py
index 2364c65cf..58d5eb2f5 100644
--- a/examples/studypal/studypal.py
+++ b/examples/studypal/studypal.py
@@ -131,7 +131,9 @@ async def main():
             api_key=os.getenv("CARTESIA_API_KEY"),
             voice_id=os.getenv("CARTESIA_VOICE_ID", "4d2fd738-3b3d-4368-957a-bb4805275bd9"),
             # British Narration Lady: 4d2fd738-3b3d-4368-957a-bb4805275bd9
-            sample_rate=44100,
+            params=CartesiaTTSService.InputParams(
+                sample_rate=44100,
+            ),
         )
 
         llm = OpenAILLMService(api_key=os.getenv("OPENAI_API_KEY"), model="gpt-4o-mini")
diff --git a/src/pipecat/services/cartesia.py b/src/pipecat/services/cartesia.py
index 90deeda15..c1c296046 100644
--- a/src/pipecat/services/cartesia.py
+++ b/src/pipecat/services/cartesia.py
@@ -9,7 +9,8 @@
 import base64
 import asyncio
 
-from typing import AsyncGenerator
+from typing import AsyncGenerator, Optional, Union, List
+from pydantic.main import BaseModel
 
 from pipecat.frames.frames import (
     CancelFrame,
@@ -61,6 +62,14 @@ def language_to_cartesia_language(language: Language) -> str | None:
 
 
 class CartesiaTTSService(AsyncWordTTSService):
+    class InputParams(BaseModel):
+        encoding: Optional[str] = "pcm_s16le"
+        sample_rate: Optional[int] = 16000
+        container: Optional[str] = "raw"
+        language: Optional[str] = "en"
+        speed: Optional[Union[str, float]] = ""
+        emotion: Optional[List[str]] = []
+
     def __init__(
         self,
         *,
@@ -69,9 +78,7 @@ def __init__(
         cartesia_version: str = "2024-06-10",
         url: str = "wss://api.cartesia.ai/tts/websocket",
         model_id: str = "sonic-english",
-        encoding: str = "pcm_s16le",
-        sample_rate: int = 16000,
-        language: str = "en",
+        params: InputParams = InputParams(),
         **kwargs,
     ):
         # Aggregating sentences still gives cleaner-sounding results and fewer
@@ -85,20 +92,26 @@ def __init__(
         # can use those to generate text frames ourselves aligned with the
         # playout timing of the audio!
         super().__init__(
-            aggregate_sentences=True, push_text_frames=False, sample_rate=sample_rate, **kwargs
+            aggregate_sentences=True,
+            push_text_frames=False,
+            sample_rate=params.sample_rate,
+            **kwargs,
         )
 
         self._api_key = api_key
         self._cartesia_version = cartesia_version
         self._url = url
         self._voice_id = voice_id
+        self._model_id = model_id
         self.set_model_name(model_id)
         self._output_format = {
-            "container": "raw",
-            "encoding": encoding,
-            "sample_rate": sample_rate,
+            "container": params.container,
+            "encoding": params.encoding,
+            "sample_rate": params.sample_rate,
         }
-        self._language = language
+        self._language = params.language
+        self._speed = params.speed
+        self._emotion = params.emotion
 
         self._websocket = None
         self._context_id = None
@@ -108,6 +121,7 @@ def can_generate_metrics(self) -> bool:
         return True
 
     async def set_model(self, model: str):
+        self._model_id = model
         await super().set_model(model)
         logger.debug(f"Switching TTS model to: [{model}]")
 
@@ -115,10 +129,42 @@ async def set_voice(self, voice: str):
         logger.debug(f"Switching TTS voice to: [{voice}]")
         self._voice_id = voice
 
+    async def set_speed(self, speed: str):
+        logger.debug(f"Switching TTS speed to: [{speed}]")
+        self._speed = speed
+
+    async def set_emotion(self, emotion: list[str]):
+        logger.debug(f"Switching TTS emotion to: [{emotion}]")
+        self._emotion = emotion
+
     async def set_language(self, language: Language):
         logger.debug(f"Switching TTS language to: [{language}]")
         self._language = language_to_cartesia_language(language)
 
+    def _build_msg(
+        self, text: str = "", continue_transcript: bool = True, add_timestamps: bool = True
+    ):
+        voice_config = {"mode": "id", "id": self._voice_id}
+
+        if self._speed or self._emotion:
+            voice_config["__experimental_controls"] = {}
+            if self._speed:
+                voice_config["__experimental_controls"]["speed"] = self._speed
+            if self._emotion:
+                voice_config["__experimental_controls"]["emotion"] = self._emotion
+
+        msg = {
+            "transcript": text,
+            "continue": continue_transcript,
+            "context_id": self._context_id,
+            "model_id": self._model_name,
+            "voice": voice_config,
+            "output_format": self._output_format,
+            "language": self._language,
+            "add_timestamps": add_timestamps,
+        }
+        return json.dumps(msg)
+
     async def start(self, frame: StartFrame):
         await super().start(frame)
         await self._connect()
@@ -134,7 +180,8 @@ async def cancel(self, frame: CancelFrame):
     async def _connect(self):
         try:
             self._websocket = await websockets.connect(
-                f"{self._url}?api_key={self._api_key}&cartesia_version={self._cartesia_version}"
+                f"{self._url}?api_key={self._api_key}&cartesia_version={
+                    self._cartesia_version}"
             )
             self._receive_task = self.get_event_loop().create_task(self._receive_task_handler())
         except Exception as e:
@@ -173,17 +220,8 @@ async def flush_audio(self):
         if not self._context_id or not self._websocket:
             return
         logger.trace("Flushing audio")
-        msg = {
-            "transcript": "",
-            "continue": False,
-            "context_id": self._context_id,
-            "model_id": self.model_name,
-            "voice": {"mode": "id", "id": self._voice_id},
-            "output_format": self._output_format,
-            "language": self._language,
-            "add_timestamps": True,
-        }
-        await self._websocket.send(json.dumps(msg))
+        msg = self._build_msg(text="", continue_transcript=False)
+        await self._websocket.send(msg)
 
     async def _receive_task_handler(self):
         try:
@@ -236,18 +274,10 @@ async def run_tts(self, text: str) -> AsyncGenerator[Frame, None]:
                 await self.start_ttfb_metrics()
                 self._context_id = str(uuid.uuid4())
 
-            msg = {
-                "transcript": text + " ",
-                "continue": True,
-                "context_id": self._context_id,
-                "model_id": self.model_name,
-                "voice": {"mode": "id", "id": self._voice_id},
-                "output_format": self._output_format,
-                "language": self._language,
-                "add_timestamps": True,
-            }
+            msg = self._build_msg(text=text)
+
             try:
-                await self._get_websocket().send(json.dumps(msg))
+                await self._get_websocket().send(msg)
                 await self.start_tts_usage_metrics(text)
             except Exception as e:
                 logger.error(f"{self} error sending message: {e}")
@@ -261,6 +291,14 @@ async def run_tts(self, text: str) -> AsyncGenerator[Frame, None]:
 
 
 class CartesiaHttpTTSService(TTSService):
+    class InputParams(BaseModel):
+        encoding: Optional[str] = "pcm_s16le"
+        sample_rate: Optional[int] = 16000
+        container: Optional[str] = "raw"
+        language: Optional[str] = "en"
+        speed: Optional[Union[str, float]] = ""
+        emotion: Optional[List[str]] = []
+
     def __init__(
         self,
         *,
@@ -268,9 +306,7 @@ def __init__(
         voice_id: str,
         model_id: str = "sonic-english",
         base_url: str = "https://api.cartesia.ai",
-        encoding: str = "pcm_s16le",
-        sample_rate: int = 16000,
-        language: str = "en",
+        params: InputParams = InputParams(),
         **kwargs,
     ):
         super().__init__(**kwargs)
@@ -278,12 +314,15 @@ def __init__(
         self._api_key = api_key
         self._voice_id = voice_id
         self._model_id = model_id
+        self.set_model_name(model_id)
         self._output_format = {
-            "container": "raw",
-            "encoding": encoding,
-            "sample_rate": sample_rate,
+            "container": params.container,
+            "encoding": params.encoding,
+            "sample_rate": params.sample_rate,
         }
-        self._language = language
+        self._language = params.language
+        self._speed = params.speed
+        self._emotion = params.emotion
 
         self._client = AsyncCartesia(api_key=api_key, base_url=base_url)
 
@@ -293,11 +332,20 @@ def can_generate_metrics(self) -> bool:
     async def set_model(self, model: str):
         logger.debug(f"Switching TTS model to: [{model}]")
         self._model_id = model
+        await super().set_model(model)
 
     async def set_voice(self, voice: str):
         logger.debug(f"Switching TTS voice to: [{voice}]")
         self._voice_id = voice
 
+    async def set_speed(self, speed: str):
+        logger.debug(f"Switching TTS speed to: [{speed}]")
+        self._speed = speed
+
+    async def set_emotion(self, emotion: list[str]):
+        logger.debug(f"Switching TTS emotion to: [{emotion}]")
+        self._emotion = emotion
+
     async def set_language(self, language: Language):
         logger.debug(f"Switching TTS language to: [{language}]")
         self._language = language_to_cartesia_language(language)
@@ -317,6 +365,14 @@ async def run_tts(self, text: str) -> AsyncGenerator[Frame, None]:
         await self.start_ttfb_metrics()
 
         try:
+            voice_controls = None
+            if self._speed or self._emotion:
+                voice_controls = {}
+                if self._speed:
+                    voice_controls["speed"] = self._speed
+                if self._emotion:
+                    voice_controls["emotion"] = self._emotion
+
             output = await self._client.tts.sse(
                 model_id=self._model_id,
                 transcript=text,
@@ -324,6 +380,7 @@ async def run_tts(self, text: str) -> AsyncGenerator[Frame, None]:
                 output_format=self._output_format,
                 language=self._language,
                 stream=False,
+                _experimental_voice_controls=voice_controls,
             )
 
             await self.stop_ttfb_metrics()