> ## Documentation Index
> Fetch the complete documentation index at: https://docs.bland.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# Update Voice Settings

> Update the consistency/expressiveness defaults on a voice you own.

## Overview

Updates one or more synthesis defaults on a voice you own. Equivalent to [Update Voice Config](https://docs.bland.ai/api-v1/patch/voices-id-config.md), kept under both verbs and paths for backwards compatibility. New integrations should use this `POST /settings` form.

At least one of the body fields must be provided.

***

## Headers

**authorization** `string` *required*

Your API key for authentication.

***

## Path Parameters

**id** `string` *required*

UUID of the voice.

***

## Body Parameters

**consistency** `number`

Default consistency for V1 and V2 voices. V1: 0-1 float (higher is more consistent). V2: 0-64 integer (lower is more consistent). Reject values outside that range.

**expressiveness** `number`

Default expressiveness for V1 and V2 voices. 0-1 float.

**boost\_language\_consistency** `boolean`

Boost flag for V3 voices only. `true` adds language-consistency prompting at the cost of some flexibility for code-switching. Disable if your agent needs to speak languages outside the source sample.

***

## Response

Echoes back the resolved settings on success. For V1 and V2 voices:

**consistency** `number`

**expressiveness** `number`

**service** `string`

The engine identifier of the voice.

For V3 voices:

**boost\_language\_consistency** `boolean`

**service** `string`

To see the rest of the voice's fields after an update, call [Get Voice](https://docs.bland.ai/api-v1/get/voices-id.md).

```json V2 Response theme={null}
{
  "consistency": 16,
  "expressiveness": 0.8,
  "service": "BTTS_V2"
}
```

```json V3 Response theme={null}
{
  "boost_language_consistency": true,
  "service": "BTTS_V3"
}
```

```json Nothing Provided theme={null}
{
  "data": null,
  "errors": [
    {
      "error": "INVALID_REQUEST",
      "message": "At least one of consistency, expressiveness or boost_language_consistency must be provided"
    }
  ]
}
```

```json Out of Range theme={null}
{
  "data": null,
  "errors": [
    { "error": "INVALID_CONSISTENCY", "message": "consistency must be a number between 0 and 64" }
  ]
}
```

***

Docs for agents: [llms.txt](https://docs.bland.ai/llms.txt)


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