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

# Text-to-Speech WebSocket voice settings

> Reference for provider-specific voice configuration sent in the handshake frame for Telnyx Text-to-Speech WebSocket streaming, including speed and style.

`voice_settings` is an object sent in the handshake frame to configure provider-specific parameters:

```json theme={null}
{
  "text": " ",
  "voice_settings": {
    "voice_speed": 1.2
  }
}
```

## Telnyx Natural

| Parameter     | Type  | Default | Description                         |
| ------------- | ----- | ------- | ----------------------------------- |
| `voice_speed` | float | 1.0     | Speech rate. Values > 1 are faster. |

## Telnyx NaturalHD

| Parameter     | Type  | Default | Description                         |
| ------------- | ----- | ------- | ----------------------------------- |
| `voice_speed` | float | 1.0     | Speech rate. Values > 1 are faster. |

## Telnyx Ultra

<Warning>
  Telnyx Ultra is **REST-only** — not available over WebSocket. These settings apply to the [REST API](/docs/voice/tts/rest-api).
</Warning>

| Parameter        | Type   | Default | Description                                                                      |
| ---------------- | ------ | ------- | -------------------------------------------------------------------------------- |
| `voice_speed`    | float  | 1.0     | Speech rate. Values > 1 are faster.                                              |
| `language_boost` | string | —       | Target language                                                                  |
| `volume`         | float  | —       | Volume level                                                                     |
| `emotion`        | string | —       | Emotion: `neutral`, `happy`, `sad`, `angry`, `fearful`, `disgusted`, `surprised` |

## Telnyx Qwen3TTS

| Parameter        | Type   | Default  | Description                                                                                                                                                                       |
| ---------------- | ------ | -------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `language_boost` | string | `"Auto"` | Target language. Accepted: `Auto`, `English`, `Chinese`, `French`, `German`, `Italian`, `Japanese`, `Korean`, `Portuguese`, `Russian`, `Spanish`, or ISO codes (`en`, `zh`, etc.) |

## Azure Speech

| Parameter       | Type   | Default   | Description                                |
| --------------- | ------ | --------- | ------------------------------------------ |
| `language_code` | string | `"en-US"` | Language code                              |
| `text_type`     | string | `"text"`  | Input type: `text` or `ssml`               |
| `effect`        | string | —         | Audio effect: `eq_car` or `eq_telecomhp8k` |
| `gender`        | string | —         | Voice gender filter: `Male` or `Female`    |

## AWS Polly

| Parameter       | Type   | Default      | Description                                                   |
| --------------- | ------ | ------------ | ------------------------------------------------------------- |
| `language_code` | string | —            | BCP-47 language code                                          |
| `output_format` | string | —            | Audio format override                                         |
| `engine`        | string | `"standard"` | Polly engine: `standard`, `neural`, `generative`, `long-form` |
| `text_type`     | string | `"text"`     | Input type: `text` or `ssml`                                  |
| `lexicon_names` | array  | —            | Pronunciation lexicon names                                   |

## Minimax

| Parameter        | Type    | Default | Description       |
| ---------------- | ------- | ------- | ----------------- |
| `speed`          | float   | —       | Speech rate       |
| `vol`            | float   | —       | Volume            |
| `pitch`          | integer | —       | Pitch adjustment  |
| `language_boost` | string  | —       | Language emphasis |

## Rime

| Parameter         | Type    | Default | Description                                          |
| ----------------- | ------- | ------- | ---------------------------------------------------- |
| `voice_speed`     | float   | 1.0     | Speech rate. Above 1.0 = faster, below 1.0 = slower. |
| `sampling_rate`   | integer | 24000   | Output sample rate in Hz.                            |
| `response_format` | string  | `"mp3"` | Output format: `mp3`, `pcm`, or `wav`.               |

## Inworld

| Parameter       | Type   | Default | Description                                                             |
| --------------- | ------ | ------- | ----------------------------------------------------------------------- |
| `language_code` | string | —       | Language code                                                           |
| `delivery_mode` | string | —       | `STABLE`, `BALANCED`, or `CREATIVE`. Only supported by `inworld-tts-2`. |