TTS (Text-to-Speech)
Technology that converts written text into spoken audio, the output stage of an AI voice agent.
Text-to-Speech (TTS) converts written text into natural-sounding audio. In an AI voice agent pipeline, TTS is the final stage — it takes the language model's text response and produces the audio that the caller hears.
Traditional vs. neural TTS
Early TTS systems (pre-2018) used concatenative synthesis — stitching together pre-recorded phoneme fragments — producing robotic, monotone output. Modern neural TTS uses deep learning (typically transformer models or diffusion models) to synthesize speech that closely mimics the natural patterns of human speech.
Prosody modeling is the key differentiator in neural TTS quality. It controls rhythm, pitch, stress, and pacing — the elements that make speech sound natural rather than robotic. TurboCall's neural TTS scores 99.7% on human-likeness benchmarks in blind listening tests.
Streaming TTS begins generating audio before the full text is available, reducing the delay the caller experiences between asking a question and hearing the response.
Voice selection: Modern TTS platforms offer libraries of 50–200+ voices across genders, ages, accents, and languages. TurboCall provides 100+ neural voices plus professional voice cloning.
Voice cloning is a TTS technique that creates a new synthetic voice that sounds like a specific person from a short audio sample (typically 3–5 minutes). Businesses use voice cloning to give their AI agent the voice of a spokesperson or brand character.