Ultra-low-latency TTS — the engine that makes Fluents agents sound natural with no perceptible pause.
Every Fluents call runs through three layers: Deepgram converts the caller's speech to text, the conversation engine (Gemini by default) generates the agent's response, and the TTS layer converts that response into natural speech. Cartesia is available as the TTS engine in that third layer — specialized in streaming synthesis with extremely low latency.
Where most TTS systems generate audio in chunks with noticeable gaps, Cartesia's streaming architecture begins outputting audio within milliseconds of receiving text — making the agent's voice feel like a natural, flowing response rather than a robotic readout.
Cartesia's streaming synthesis begins playing audio within milliseconds of the conversation engine generating text — the closest thing to zero latency TTS available
High-quality natural voices with configurable tone and pace — agents sound like professional human speakers, not synthesized robotics
Optimized for real-time conversational flow — designed specifically for voice AI applications where natural rhythm is critical to caller experience
The Three-Layer Fluents Stack
When a caller speaks, Deepgram transcribes it to text in real time. The conversation engine reads that text, determines what the agent should say, and generates a text response. Cartesia takes that text and synthesizes it into speech. The total response time the caller experiences is the sum of all three layers. Cartesia compresses the synthesis step to near-zero — meaning the agent's words start playing almost as soon as the conversation engine finishes generating them.
Insurance: Natural FNOL Conversations Without Robotic Pauses
A policyholder calling to report an accident is already stressed. An agent that pauses unnaturally before each sentence, or whose voice sounds mechanical, creates friction at a moment that should feel supportive and efficient. Cartesia's streaming synthesis delivers natural-sounding responses with no perceptible gap — making the FNOL call feel like speaking with a knowledgeable person, not filling out an automated form.
Healthcare: Patient Calls That Feel Human
Patient communication requires warmth and naturalness. A discharge follow-up call from an agent that sounds robotic and hesitant undermines confidence in the care system. Cartesia's high-quality voice synthesis, combined with Fluents' intelligent conversation layer, produces patient interactions that pass the naturalness bar — patients respond, engage, and complete the interaction without the friction of obvious AI tells.
High-Volume Outbound: Quality at Scale
At thousands of simultaneous calls, synthesis quality and consistency matter as much as latency. Cartesia maintains consistent voice quality across every concurrent call — no degradation, no variation, no robotic artifacts from inference load. Every caller gets the same natural agent voice.