Voice Activity Detection (VAD)

Voice Activity Detection (VAD) identifies segments of speech in audio data. LocalAI provides a /v1/vad endpoint powered by the Silero VAD backend.

API

Method: POST
Endpoints: /v1/vad, /vad

Request

The request body is JSON with the following fields:

Parameter	Type	Required	Description
`model`	`string`	Yes	Model name (e.g. `silero-vad`)
`audio`	`float32[]`	Yes	Array of audio samples (16kHz PCM float)

Response

Returns a JSON object with detected speech segments:

Field	Type	Description
`segments`	`array`	List of detected speech segments
`segments[].start`	`float`	Start time in seconds
`segments[].end`	`float`	End time in seconds

Usage

Example request

curl http://localhost:8080/v1/vad \
  -H "Content-Type: application/json" \
  -d '{
    "model": "silero-vad",
    "audio": [0.0012, -0.0045, 0.0053, -0.0021, ...]
  }'

Example response

{
  "segments": [
    {
      "start": 0.5,
      "end": 2.3
    },
    {
      "start": 3.1,
      "end": 5.8
    }
  ]
}

Model Configuration

Create a YAML configuration file for the VAD model:

name: silero-vad
backend: silero-vad

Detection Parameters

The Silero VAD backend uses the following internal defaults:

Sample rate: 16kHz
Threshold: 0.5
Min silence duration: 100ms
Speech pad duration: 30ms

Error Responses

Status Code	Description
400	Missing or invalid `model` or `audio` field
500	Backend error during VAD processing