***

id: 967bb43c-abe7-4038-8423-4ba5f7cb50ea
title: OpenAI
description: Learn how to use OpenAI TTS voices on the SignalWire platform.
slug: /voice/tts/openai
-----------------------

OpenAI offers versatile multilingual voices balancing low latency and good quality.
While voices are optimized for English, they perform well across all
[supported languages][languages].

Consult
[OpenAI's Text-to-Speech documentation][tts]
for more information and audio samples for available voices.

## Models

OpenAI offers two TTS models with different quality and latency characteristics:

| Model      | Description                                         |
| ---------- | --------------------------------------------------- |
| `tts-1`    | **Default** - Standard quality, optimized for speed |
| `tts-1-hd` | High-definition quality, improved audio fidelity    |

## Voices

OpenAI provides 6 fully multilingual voices optimized for natural-sounding speech:

| Voice     | Description                |
| --------- | -------------------------- |
| `alloy`   | Neutral, balanced voice    |
| `echo`    | Warm, expressive voice     |
| `fable`   | British accent, articulate |
| `onyx`    | Deep, authoritative voice  |
| `nova`    | Energetic, friendly voice  |
| `shimmer` | Soft, gentle voice         |

## Languages

All OpenAI voices are fully multilingual and automatically adapt to the input text language.

Consult OpenAI's [supported languages resource][languages]
for an up-to-date list.

## Usage

OpenAI voice IDs conform to the following format:

```
openai.<voice>:<model>
```

**Parameters:**

* `voice` (required): One of: alloy, echo, fable, onyx, nova, shimmer
* `model` (optional): `tts-1` (default) or `tts-1-hd`

**Examples:**

```
openai.alloy
openai.nova:tts-1-hd
openai.fable:tts-1
```

***

## Examples

Learn how to use OpenAI voices on the SignalWire platform.

<Tabs>
  <Tab title="SWML">
    Use the
    [**`languages`**](/docs/swml/reference/ai/languages#use-voice-strings)
    SWML method to set one or more voices for an [AI agent](/docs/swml/reference/ai).

    ```yaml
    version: 1.0.0
    sections:
      main:
      - ai:
          prompt:
            text: Have an open-ended conversation about flowers.
          languages:
            - name: English
              code: en-US
              voice: openai.alloy
    ```

    Alternatively, use the [**`say_voice`** parameter](/docs/swml/reference/play#variables)
    of the [**`play`**](/docs/swml/reference/play)
    SWML method to select a voice for basic TTS.

    ```yaml
    version: 1.0.0
    sections:
      main:
      - set:
          say_voice: "openai.alloy"
      - play: "say:Greetings. This is the Alloy voice from OpenAI's text-to-speech model."
    ```
  </Tab>

  <Tab title="RELAY Realtime SDK">
    ```javascript
    // This example uses the Node.js SDK for SignalWire's RELAY Realtime API.
    const playback = await call.playTTS({ 
        text: "Greetings. This is the Alloy voice from OpenAI's text-to-speech model.",
        voice: "openai.alloy",
    });
    await playback.ended();
    ```
  </Tab>

  <Tab title="Call Flow Builder">
    OpenAI voices are not yet supported in Call Flow Builder.
  </Tab>
</Tabs>

{/* Links */}

[languages]: https://platform.openai.com/docs/guides/text-to-speech#supported-languages "OpenAI reference on supported languages."

[tts]: https://platform.openai.com/docs/guides/text-to-speech#supported-languages "OpenAI TTS documentation."