Voice Configuration

You can configure how your persona’s voice sounds — speed, volume, and emotion — via voiceGenerationOptions in the persona config. The available options depend on the provider and model of the configured voice.

const personaConfig = {
  name: "Cara",
  avatarId: "30fa96d0-26c4-4e55-94a0-517025942e18",
  avatarModel: "cara-4",
  voiceId: "6bfbe25a-979d-40f3-a92b-5394170af54b",
  llmId: "a7cf662c-2ace-4de1-a21e-ef0fbf144bb7",
  systemPrompt: "You are Cara, a helpful customer service representative.",
  voiceGenerationOptions: {
    speed: 1.2,
    volume: 0.8,
    emotion: "content"
  }
};

These settings can be set when creating or updating a persona, as well as when generating a session token. See the API Reference for details.

Cartesia voices

The following options are valid for Cartesia sonic-3 voices:

Option	Range	Description
`volume`	0.5 – 2.0	Multiplier to decrease or increase the volume of the original voice
`speed`	0.6 – 1.5	Multiplier to decrease or increase the speed of the original voice
`emotion`	string	Emotion to apply: `neutral`, `calm`, `angry`, `content`, `sad`, `scared`

ElevenLabs voices

The following options are valid for ElevenLabs v1 and v2 voices:

Option	Range	Description
`stability`	0 – 1	How much the voice varies between generations. Lower values introduce more emotional variation
`similarityBoost`	0 – 1	How closely the generated voice matches the original reference audio
`speed`	0.7 – 1.2	Multiplier to decrease or increase the speed of the original voice

For v2 voices, these additional options are also available:

Option	Type	Description
`useSpeakerBoost`	boolean	Boost similarity to the original speaker. May increase latency
`style`	0 – 1	How much the original speaker’s style is amplified. Values other than 0 may increase latency

Changing voices

The voiceGenerationOptions are specific to the provider, model, and voice being used. When you change the voiceId for a persona, these options reset. Use the copy persona feature in Lab when experimenting with different voices to avoid losing your existing config.

Introduction

Personas

Security & Network

Resources

Voice Configuration

Cartesia voices

ElevenLabs voices

Changing voices

​Cartesia voices

​ElevenLabs voices

​Changing voices

Cartesia voices

ElevenLabs voices

Changing voices