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Class: BuiltInAdaptiveVadProvider

Defined in: packages/agentos/src/hearing/providers/BuiltInAdaptiveVadProvider.ts:92

Built-in voice activity detection (VAD) provider backed by the AdaptiveVAD engine and EnvironmentalCalibrator.

This is the default VAD provider in AgentOS and requires no external dependencies or API keys. It operates entirely locally on raw audio frames.

How It Works​

  1. The EnvironmentalCalibrator continuously estimates the ambient noise floor and spectral profile from incoming audio frames.
  2. The AdaptiveVAD uses the calibrator's noise profile to set dynamic thresholds for speech detection — louder environments get higher thresholds to avoid false positives.
  3. Each processFrame() call returns a SpeechVadDecision with isSpeech, confidence, the raw VAD result, and the current noise profile.

Configuration Defaults​

  • Sample rate: 16 kHz (standard for voice pipelines)
  • Frame duration: 20ms (320 samples per frame)
  • VAD and calibration: Use sensible defaults from the underlying engines

See​

BuiltInAdaptiveVadProviderConfig for configuration options See AdaptiveVAD for the underlying VAD algorithm. See EnvironmentalCalibrator for the noise profiling engine.

Example​

const vad = new BuiltInAdaptiveVadProvider({
  sampleRate: 16_000,
  frameDurationMs: 20,
  vad: { minSpeechDurationMs: 100 },
});

const frame = new Float32Array(320); // 20ms at 16kHz
// ... fill frame with audio samples ...
const decision = vad.processFrame(frame);
if (decision.isSpeech) {
  console.log(`Speech detected (confidence: ${decision.confidence})`);
}

Implements​

Constructors​

Constructor​

new BuiltInAdaptiveVadProvider(config?): BuiltInAdaptiveVadProvider

Defined in: packages/agentos/src/hearing/providers/BuiltInAdaptiveVadProvider.ts:133

Creates a new BuiltInAdaptiveVadProvider.

Initializes both the environmental calibrator and the adaptive VAD engine with the provided or default configuration.

Parameters​

config?​

BuiltInAdaptiveVadProviderConfig = {}

Optional VAD configuration. All fields default to standard values suitable for 16kHz mono voice audio.

Returns​

BuiltInAdaptiveVadProvider

Example​

// Default configuration (16kHz, 20ms frames)
const vad = new BuiltInAdaptiveVadProvider();

// Custom configuration
const vad = new BuiltInAdaptiveVadProvider({
  sampleRate: 48_000,
  frameDurationMs: 10,
  vad: { minSpeechDurationMs: 200 },
});

Properties​

displayName​

readonly displayName: "AgentOS Adaptive VAD" = 'AgentOS Adaptive VAD'

Defined in: packages/agentos/src/hearing/providers/BuiltInAdaptiveVadProvider.ts:97

Human-readable display name for UI and logging.

Implementation of​

SpeechVadProvider.displayName

id​

readonly id: "agentos-adaptive-vad" = 'agentos-adaptive-vad'

Defined in: packages/agentos/src/hearing/providers/BuiltInAdaptiveVadProvider.ts:94

Unique provider identifier used for registration and resolution.

Implementation of​

SpeechVadProvider.id

Methods​

getNoiseProfile()​

getNoiseProfile(): NoiseProfile | null

Defined in: packages/agentos/src/hearing/providers/BuiltInAdaptiveVadProvider.ts:207

Returns the current environmental noise profile estimated by the calibrator.

The noise profile includes the estimated noise floor RMS, spectral shape, and confidence metrics. Returns null if insufficient audio has been processed for a reliable estimate.

Returns​

NoiseProfile | null

The current noise profile, or null if not yet calibrated.

Example​

const profile = vad.getNoiseProfile();
if (profile) {
  console.log(`Noise floor: ${profile.noiseFloorRms}`);
}

Implementation of​

SpeechVadProvider.getNoiseProfile

processFrame()​

processFrame(frame): SpeechVadDecision

Defined in: packages/agentos/src/hearing/providers/BuiltInAdaptiveVadProvider.ts:162

Process a single audio frame and return a speech/non-speech decision.

This method must be called sequentially with consecutive audio frames. The VAD maintains internal state (speech onset tracking, hangover counters) that depends on temporal continuity between frames.

Parameters​

frame​

Float32Array

A Float32Array of audio samples for one frame. The expected length is sampleRate * frameDurationMs / 1000 (e.g. 320 for 16kHz/20ms). Samples should be normalized to the range [-1.0, 1.0].

Returns​

SpeechVadDecision

A decision object with isSpeech, confidence, the raw VAD result, and the current environmental noise profile.

Example​

const frame = new Float32Array(320);
// ... fill with audio samples ...
const decision = vad.processFrame(frame);
console.log(decision.isSpeech, decision.confidence);

Implementation of​

SpeechVadProvider.processFrame

reset()​

reset(): void

Defined in: packages/agentos/src/hearing/providers/BuiltInAdaptiveVadProvider.ts:186

Reset the VAD state for a new audio session.

Clears internal counters (speech onset tracking, hangover timers) so the VAD starts fresh. Should be called when starting a new conversation turn or after a significant audio gap. Does NOT reset the environmental calibrator — the noise profile persists across resets.

Returns​

void

Example​

// Start a new conversation turn
vad.reset();

Implementation of​

SpeechVadProvider.reset