> ## 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](/api-v1/patch/voices-id-config), 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

<ParamField header="authorization" type="string" required>
  Your API key for authentication.
</ParamField>

***

## Path Parameters

<ParamField path="id" type="string" required>
  UUID of the voice.
</ParamField>

***

## Body Parameters

<ParamField body="consistency" type="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.
</ParamField>

<ParamField body="expressiveness" type="number">
  Default expressiveness for V1 and V2 voices. 0-1 float.
</ParamField>

<ParamField body="boost_language_consistency" type="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.
</ParamField>

***

## Response

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

<ResponseField name="consistency" type="number" />

<ResponseField name="expressiveness" type="number" />

<ResponseField name="service" type="string">
  The engine identifier of the voice.
</ResponseField>

For V3 voices:

<ResponseField name="boost_language_consistency" type="boolean" />

<ResponseField name="service" type="string" />

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

<ResponseExample>
  ```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" }
    ]
  }
  ```
</ResponseExample>

***

Docs for agents: [llms.txt](/llms.txt)