VADSpeechStartEvent

Emitted when the local VAD confirms the user has started speaking.

Defined in: src/core/events/types.ts:1227

Emitted when the local VAD confirms the user has started speaking.

Remarks

Fires after VADConfig.minSpeechDurationMs of sustained speech probability — independent of the STT provider, and typically well before any transcription text arrives. Useful for instant speaking indicators and as the trigger for provider-independent barge-in.

Example

agent.on('vad.speechStart', ({ probability }) => {
  showSpeakingIndicator(probability);
});

See

VADConfig for enabling and tuning local VAD
VADEvent for all VAD event types

Extends

BaseEvent

Properties

Property	Type	Description	Inherited from	Defined in
`metadata?`	`Record`<`string`, `unknown`>	Optional metadata associated with the event. Remarks May contain provider-specific data or debugging information.	`BaseEvent.metadata`	src/core/events/types.ts:94
`probability`	`number`	Speech probability of the frame that confirmed the detection (0–1).	-	src/core/events/types.ts:1232
`timestamp`	`number`	Unix timestamp (in milliseconds) when the event occurred. Remarks Useful for latency measurements and debugging the pipeline timing.	`BaseEvent.timestamp`	src/core/events/types.ts:86
`type`	`"vad.speechStart"`	Discriminant for this event type.	-	src/core/events/types.ts:1229