Home
Contact usLog inSign up
Release notes

xAI Grok Voices Now Available for Telnyx Voice AI Assistants

27, Apr 2026

xAI Grok voices are now available for Telnyx Voice AI Assistants, adding five new expressive voices to the TTS lineup. Grok voices support Expressive Mode, letting AI agents dynamically adjust tone and emotion during live conversations across 20+ languages.

What's new

  • Five new voices: Ara, Eve, Leo, Rex, and Sal, each with distinct character and tone for different conversational styles.
  • Expressive Mode support: Grok voices join Telnyx Ultra as the second TTS provider supporting Expressive Mode, where the AI model dynamically controls emotional delivery using inline speech tags for pauses, laughter, whispers, and emphasis.
  • 20+ languages: Auto-detected language support across the Grok voice set, with BCP-47 code support for consistent output.
  • Inline speech tags: Fine-grained control over delivery, including pauses, laughter, whispers, and emphasis, without hard-coding emotions into prompts.

Why it matters

  • Expressive, emotionally adaptive voices make AI agents sound more natural and keep callers engaged longer. Agents that adjust tone in real time, responding with empathy or enthusiasm based on context, create conversations that feel less scripted and more human.
  • More TTS providers with Expressive Mode means more voice options for different brands, industries, and use cases. Teams can pick the voice that matches their identity without sacrificing emotional expressiveness.
  • On-network processing: Grok voices run through Telnyx-hosted models, keeping audio and inference on the same private backbone.

Example use cases

  • Customer support teams building empathetic agents that shift tone based on whether a caller is frustrated or satisfied.
  • Healthcare and wellness apps using whisper-capable voices for calm, guided interactions.
  • Entertainment and gaming companies leveraging expressive laughter and emphasis for character-driven voice experiences.

Getting started

  1. Go to Mission Control → AI → Assistants → select your assistant → Voice tab.
  2. Select an xAI Grok voice (Ara, Eve, Leo, Rex, or Sal).
  3. Toggle Expressive Mode on.
  4. Save your assistant.

Note: Grok voices with Expressive Mode have higher latency than Telnyx Ultra voices. For latency-sensitive applications, Telnyx Ultra remains the recommended provider with sub-100ms time to first byte.

Learn more in the xAI Grok TTS documentation or the Voice AI Agents overview.