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

# Speech-to-text (STT)

> Learn how to transribe user audio.(STT, Speech-to-text)

Speech-to-text (STT) is a technology that converts audio input into text. It allows users to interact with AI Agents using their voice.

## Overview

There are two ways to use the speech-to-text feature:

* **Real-time STT**: Transcribes incoming audio tracks in real-time. Ideal when low-latency feedback is important.
* **Non-real-time STT**: Transcribes audio blobs. Suitable when you already have a user audio recording implementation.

## Real-time STT

As a recommended approach, it connects to the user’s audio track and streams the transcription result in real time.

#### Configuration

You can configure STT options in the config when calling join(). You may explicitly specify a language or enable automatic language detection. Specifying a language improves transcription accuracy. (link) If no language is specified, STT runs in the same language as the AI Avatar.

```typescript theme={null}
await room.join({
  sessionId: "your-session-id",
  streamId: "your-stream-id",
  token: "your-token",
  config: {
    stt: {
      language: "ko",
    },
    unmuteUserAudioOnJoined: true,
  },
});
```

With this configuration, STT will automatically start when the `joined` event is triggered.

#### Start transcription

```typescript theme={null}
room.unmuteUserAudio(); // publish user audio track and unmute
```

Unmutes the user’s audio. If the track is already published, it resumes sending audio data. If it is not published, it publishes the track and starts transmitting data.

#### Stop transcription

```typescript theme={null}
room.muteUserAudio(); // mute user audio track
room.unpublishUserAudio(); // unpublish user audio track
```

Both methods stop STT.
The difference is that unpublishUserAudio() disconnects the audio track entirely, while `muteUserAudio()` keeps the track published but stops sending audio data.

To resume STT, use `unmuteUserAudio()`.
If you stopped STT using `muteUserAudio()`, it can resume more quickly, so this is the recommended approach.

#### Transcription results

Transcription results are delivered via events.

```typescript theme={null}
room.on("stt-data", (data) => {
  const { type, text, eventType } = data;
  console.log(data);
});
room.on("stt-error", () => {});
```

By default, transcription uses the same language as the agent.
If you’d like to detect the spoken language automatically, you can configure that when joining the room.(link)

## Non-real-time STT

Converts a recorded audio blob into text.

```typescript theme={null}
const blob = await room.stopRecordingAudio();
const text = await room.stt(blob, "ko");
```

To learn more and see full feature, see the following topics:

<CardGroup cols="2">
  <Card title="STT Instance methods" icon="signal-stream" href="/pages/instance_Methods#unmuteuseraudio">
    Reference for STT instance methods.
  </Card>

  <Card title="STT Events" icon="signal-stream" href="/pages/events#param-stt-data">
    Reference for STT Events.
  </Card>
</CardGroup>