Class BuiltInAdaptiveVadProvider

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

Methods

processFrame reset getNoiseProfile

Properties

id displayName

Constructors

constructor

  • new BuiltInAdaptiveVadProvider(config?): BuiltInAdaptiveVadProvider

  • Creates a new BuiltInAdaptiveVadProvider.

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

    Parameters

    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 },
    });

Methods

processFrame

  • processFrame(frame): SpeechVadDecision

  • 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<ArrayBufferLike>

      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);

reset

  • reset(): void

  • 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();

getNoiseProfile

  • getNoiseProfile(): null | NoiseProfile

  • 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 null | NoiseProfile

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

    Example

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

Properties

Readonly id

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

Unique provider identifier used for registration and resolution.

Readonly displayName

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

Human-readable display name for UI and logging.

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