EVI can use any voice from the Voice Library or a Custom Voice you have created. You can choose from more than 100 predesigned voices or design and clone voices with the voice model to create a unique sound.

This guide explains the available voice types, how to set them in your EVI configuration, and how to override the configured voice for a single session.

## Voice options

EVI supports two types of voices:

| Voice Type     | Provider      | Description                                                                 |  
|----------------|---------------|-----------------------------------------------------------------------------|  
| Voice Library  | `HUME_AI`    | Predesigned voices available to all users. Includes over 100 styles you can preview and use immediately. |  
| Custom Voice   | `CUSTOM_VOICE`| Voices you have designed or cloned. These are stored in your account and only accessible to you. |

You can browse and preview both in the Platform’s [Voice Library](https://app.hume.ai/voices) page.

## Voice configuration

You can set the voice for your EVI configuration through the Platform UI or the API.

### UI

1. Visit the [EVI Playground](https://app.hume.ai/evi/playground).
2. In the config panel on the right, select the configuration you want to update.
3. Select a voice from your saved voices or from the Voice Library.
4. Click **Save** to update the configuration.

### API

When creating or updating an EVI configuration via the API, include the [`voice`](https://dev.hume.ai/reference/speech-to-speech-evi/configs/create-config#request.body.voice) field in the request body.

- You can specify a voice by its `id` or `name`.
- Each voice belongs to a `provider`.

| Provider       | Description                                                                 |  
|----------------|-----------------------------------------------------------------------------|  
| `HUME_AI`      | Voices from the Voice Library. These are available to all users.          |  
| `CUSTOM_VOICE` | Voices you have designed or cloned. These are private to your account.    |

**`CUSTOM_VOICE` is the default provider.** To use a Voice Library voice, explicitly set **`provider`** to **`HUME_AI`**.

```shell
curl https://api.hume.ai/v0/evi/configs \
 -H "X-Hume-Api-Key: $HUME_API_KEY" \
 --json '{\n    "evi_version": "3",\n    "name": "Example Config",\n    "voice": {\n      "id": "9e068547-5ba4-4c8e-8e03-69282a008f04",\n      "provider": "HUME_AI"\n    }\n  }'
```

## Dynamic voice selection

You can override the voice in your EVI configuration for a single chat session by including a [`voice_id`](https://dev.hume.ai/reference/speech-to-speech-evi/chat#request.query.voice_id) as a query parameter in your [handshake request](https://dev.hume.ai/reference/speech-to-speech-evi/chat).

The `voice_id` must reference either a Custom Voice in your account or a Voice Library voice available to all users.

**This override applies only to the current chat session** and does not update the saved configuration.

```javascript
'use client';
import { useVoice } from "@humeai/voice-react";

export function Chat({ accessToken }: { accessToken: string }) {\n  const { connect, disconnect, status } = useVoice();\n  return (\n    <button\n      onClick={() =>\n        status.value === 'connected'\n          ? disconnect()\n          : connect({\n              auth: { type: 'accessToken', value: accessToken },\n              configId: process.env.NEXT_PUBLIC_HUME_CONFIG_ID,\n              voiceId: "9e068547-5ba4-4c8e-8e03-69282a008f04"\n            })\n      }\n    >\n      {status.value === 'connected' ? 'End Call' : 'Start Call'}\n    </button>\n  );\n}
```

## Resources

[Voice Library Browse predesigned voices.](https://app.hume.ai/voices)  
[Voice Design Guide Design and create a custom voice.](https://dev.hume.ai/docs/voice/voice-design)  
[Voice Cloning Guide Clone a voice from a live recording or audio file.](https://dev.hume.ai/docs/voice/voice-cloning)  
[Voice Management Guide View, rename, and delete saved voices.](https://dev.hume.ai/docs/voice/management)