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

# Streaming VAD

> Real-time voice activity detection with event callbacks.

## Overview

For streaming workloads, maintain a `VadStreamState` and process chunks individually. Each call emits at most one `VadStreamEvent` describing a speech start or end boundary.

## Quick Start

```swift theme={null}
import FluidAudio

let manager = try await VadManager()
var state = await manager.makeStreamState()

for chunk in microphoneChunks {
    let result = try await manager.processStreamingChunk(
        chunk,
        state: state,
        config: .default,
        returnSeconds: true,
        timeResolution: 2
    )

    state = result.state
    print(String(format: "Probability: %.3f", result.probability))

    if let event = result.event {
        switch event.kind {
        case .speechStart:
            print("Speech began at \(event.time ?? 0) s")
        case .speechEnd:
            print("Speech ended at \(event.time ?? 0) s")
        }
    }
}
```

## VadStreamResult

| Property      | Type              | Description                           |
| ------------- | ----------------- | ------------------------------------- |
| `state`       | `VadStreamState`  | Updated state for next chunk          |
| `event`       | `VadStreamEvent?` | Speech start/end (only at boundaries) |
| `probability` | `Float`           | Raw VAD probability (0.0-1.0)         |

## Notes

* Chunks don't need to be exactly 4096 samples
* Call `makeStreamState()` to reset (equivalent to Silero's `reset_states`)
* Use `probability` for custom thresholding alongside the built-in hysteresis