Voice Mode
Choose how your AI agent talks with callers. There are two voice modes:- Live voice (recommended): One realtime model listens and speaks, so replies come almost instantly and callers can interrupt naturally. Pick a ready-made voice and go.
- Classic voice: A separate transcriber and voice, with a short pause before each reply. It supports 100+ languages, custom or cloned voices, and fine-tuning for noisy places.
Switching Modes
Click the mode you want, then click Switch to Live voice or Switch to Classic voice to confirm. Nothing changes until you confirm, and you can click Cancel to keep your current mode.Saving puts your changes in a draft. Your customers see them once you click Publish in the top-right corner. A few settings go live as soon as you save. See Drafts and versions.
Credit Usage
Voice sessions consume credits based on two components:- AI agent voice: Every voice session consumes 6 message credits per minute. This is a per-minute cost regardless of the actual messages exchanged.
- AI model: Each response from the AI agent during a voice session consumes message credits based on the model used, just like in text conversations. See the full list of models and their message credit costs.
Pricing Example
Pricing Example
Suppose your voice AI agent uses GPT-6 Luna (1 message credit per request).If a user has a 10-minute voice call with 15 AI requests:
Voice Model
Select the AI model used specifically for voice sessions. This model is separate from the one used for text-based conversations and only applies when users interact with your AI agent through voice. You can also adjust the Temperature to control how creative or reserved the AI agent’s responses are during voice conversations.
Live Voice
When your AI agent uses Live voice, choose its voice and describe how it should sound.
- Voice: Click the voice selector to browse the Live voices, preview them, and pick one.
- Speaking style: Describe how the voice should sound, such as its tone, pace, formality and emotion. What your AI agent says still comes from its instructions. Up to 500 characters.
- Write it in the language your AI agent speaks.
- Describe the sound, not the content. Put rules about what to say in your instructions.
- Be specific about pace, for example “speak slowly and clearly” rather than “speak well”.
Transcriber
The transcriber only applies to Classic voice.
- Language: The language used to transcribe user speech. Select Multilingual (auto-detect) to let the transcriber detect the language automatically, or pick a specific language to improve accuracy.
- Model: The speech-to-text model that converts user audio into text. Each model supports a different range of languages.
- Silence Threshold: Seconds of silence before the AI agent considers the user has finished speaking. Lower values switch turns faster but may cut off pauses mid-thought.
- Noise Sensitivity: Controls how loud audio must be to count as speech. Lower values pick up quieter speech but are more sensitive to background noise. Higher values filter out noise but may miss soft-spoken users.
Multiple transcription languages: When using the default Soniox v5 model, you can select up to 8 languages. Limiting the set of possible languages helps the transcriber focus on the selected languages, improving transcription accuracy.
AI Agent Voice
These settings only apply to Classic voice. For Live voice, see Live Voice.
- Speed: Controls how fast or slow the AI agent speaks. Adjust the slider between slower and faster to match your preferred pace.
- Stability: Determines how stable the voice is. Lower values introduce a broader emotional range, while higher values produce a more consistent, monotone delivery with limited emotion.
- Similarity: Determines how closely the AI adheres to the original voice when replicating it. Higher values result in a closer match to the selected voice.
- Voice instructions: For voices that support it, enter a short prompt describing the tone, style, or dialect you want the AI agent to use when speaking.
Saving puts your changes in a draft. Your customers see them once you click Publish in the top-right corner. A few settings go live as soon as you save. See Drafts and versions.
Selecting a voice
The voice picker has two tabs: All voices for browsing pre-recorded voices, and Custom voice for bringing a custom voice from a supported provider.
- Provider: The voice provider that hosts the custom voice (for example, ElevenLabs).
- Voice ID: The identifier of the voice in the provider’s account. Paste it in and click Add voice to make it available for selection, then click Confirm voice to apply it to your AI agent.
Custom voices only work with publicly available shared voices from your provider. Private voices in your provider account are not supported.
Using Dialects and Regional Accents
Some voices support custom dialects and accents through Voice Instructions. Look for voices marked with the ✨ sparkle icon. These voices can adapt their accent, dialect, pacing, and speaking style based on the instructions you provide.
- Transcriber: Soniox
- Voice LLM: GPT-6 Luna or Gemini 3.8 Flash
Pronunciations
Use this to fix words your agent says wrong, like brand names, product names, or acronyms.
- Word or phrase: The word as it is written, for example
SQL. - Spoken as: How the agent should say it, spelled the way it sounds, for example
sequel.
Messages
Configure the initial greeting and error messages for your voice AI agent.
- Initial message: The first message the AI agent speaks when a voice session begins. If left empty, the voice AI agent will wait for the user to speak first.
- Error message: The message played if the voice session encounters an error. If left empty, the default error message “The voice session encountered an error. Please try again.” will be used.
Session Configurations
Control how the AI agent handles interruptions, silence, and text input during active voice calls.
- Allow interruptions: When enabled, users can speak over the AI agent to interject mid-response. Disable this if you’d prefer the AI agent to always finish speaking before listening for the user’s next turn. Defaults to enabled.
- End conversation after silence: The number of seconds of inactivity after which the call is automatically ended. Useful for closing out abandoned sessions and avoiding unnecessary credit usage. Defaults to 300 seconds.
- Allow text input during voice calls: When enabled, users can type messages mid-call alongside speaking. Helpful for entering details that are easier to type than to say, such as names, emails, or URLs. Defaults to disabled.
Recordings
Enable recording of voice sessions for quality review and training purposes. You can also toggle Retain voice recordings forever to keep recordings indefinitely, or set a custom retention period.
Limits
Control session volume and duration to manage costs and performance.
- Max no. of concurrent voice sessions: The maximum number of voice sessions that can run at the same time. If left empty, your plan’s default limit will apply.
- Max call duration: The maximum length of a single voice call in minutes. The default is 15 minutes.
- Allowed no. of daily calls: The total number of voice calls allowed each day. If left empty, your plan’s default limit will apply.
Your subscription plan enforces account-level limits for daily sessions and concurrent sessions across all your AI agents. You can set agent-specific limits here to further restrict usage for individual AI agents.