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

# Audio (TTS / STT)

> Text-to-speech and speech-to-text via the SDK.

## Text-to-Speech

```typescript theme={null}
const audioBuffer = await theo.tts({
  text: "Welcome to Theo. How can I help you today?",
  voice: "theo-voice-warm", // Optional — see table below
  speed: 1.0,               // Optional speed multiplier
});

// audioBuffer is an ArrayBuffer — write to file or stream to client
import { writeFileSync } from "fs";
writeFileSync("output.mp3", Buffer.from(audioBuffer));
```

### Voices

| Voice                    | Character                    |
| ------------------------ | ---------------------------- |
| `theo-voice-classic`     | Neutral, versatile — default |
| `theo-voice-bright`      | Bright, clear, upbeat        |
| `theo-voice-storyteller` | Narrative, expressive        |
| `theo-voice-deep`        | Deep, authoritative          |
| `theo-voice-warm`        | Warm, professional           |
| `theo-voice-soft`        | Soft, thoughtful             |

Omitting `voice` or passing an unknown value falls back to `theo-voice-classic`.

## Speech-to-Text

```typescript theme={null}
const file = new Blob([audioBytes], { type: "audio/mp3" });
const result = await theo.stt(file, "en");

console.log(result.text);              // Transcribed text
console.log(result.language);          // Detected language
console.log(result.duration_seconds);  // Audio duration
console.log(result.usage.cost_cents);  // Cost
```