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

# Understanding VAD

> This document explains the Voice Activity Detection (VAD) feature in our Realtime Speech API.

## Overview

Voice Activity Detection (VAD) is a crucial component in speech processing systems. It is a signal processing technique used to detect the presence or absence of human speech in an audio signal. By differentiating between speech and non-speech segments, VAD optimizes the performance of real-time speech applications, including Automatic Speech Recognition (ASR), Voice over IP (VoIP), and conversational AI.

## Key Parameters in VAD

The following parameters are available for configuring VAD in your Real-Time Speech API:

### Turn Detection

* **Configuration**: Turn detection is an optional feature that can be enabled or disabled. Setting it to `null` disables turn detection.
* **Server VAD**: This is the currently supported type of turn detection. It detects the start and end of speech based on audio volume and responds at the end of the user's speech.

### Parameters for Turn Detection

| **Parameter**         | **Description**                                                                                    | **Default Value** | **Range**    |
| --------------------- | -------------------------------------------------------------------------------------------------- | ----------------- | ------------ |
| `type`                | Type of turn detection. Currently, only `server_vad` is supported.                                 | `server_vad`      | N/A          |
| `threshold`           | Activation threshold for VAD (0.0 to 1.0). Higher values require louder audio to activate.         | 0.5               | 0.0 - 1.0    |
| `prefix_padding_ms`   | Amount of audio to include before the VAD-detected speech (in milliseconds).                       | 300ms             | N/A          |
| `silence_duration_ms` | Duration of silence to detect speech stop (in milliseconds). Shorter values improve response time. | 500ms             | N/A          |
| `create_response`     | Whether to automatically generate a response when VAD is enabled.                                  | `true`            | `true/false` |

### Explanation of Parameters

* **`threshold`**: Adjust this value based on the noise level of the environment. A higher threshold is ideal for noisy settings, ensuring the model activates only for significant audio inputs.
* **`prefix_padding_ms`**: Useful for capturing audio context before detected speech starts, providing smoother interactions.
* **`silence_duration_ms`**: This parameter controls the responsiveness of the system. Lower values result in faster responses but may cut off speech during short pauses.
* **`create_response`**: Enabling this ensures the system generates a response as soon as speech is detected and stops, streamlining interaction workflows.

By fine-tuning these parameters, users can optimize VAD performance for various real-time applications, ensuring precise and efficient voice interactions.