what's the default threshold and silence time for livekit plugin silero?

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how does silero work in a pipeline agent? for example, if the stt sends a final event after 0.1s, which is a silence time for stt service, will the agent answer directly?

The Silero VAD in a pipeline agent works like this: 1. Speech Detection: Silero VAD picks up when someone starts talking and sends a

START_OF_SPEECH

event. It also keeps a little buffer of the audio for the STT service to use. 2. Silence Handling: After it detects speech, the VAD watches for a quiet moment (by default,

min_silence_duration

is 0.55 seconds). When it notices this silence, it sends an

END_OF_SPEECH

event. 3. STT Processing: Once the

END_OF_SPEECH

event is triggered, the STT service processes the buffered audio. If the STT service sends a final event after 0.1 seconds of silence, the agent waits for the VAD’s

END_OF_SPEECH

event (based on the silence duration set) before replying. This setup helps keep things running smoothly by making sure speech is detected accurately and turn-taking feels natural. Sources: tests/fake_vad.py | Speech-to-text (STT) integrations | LiveKit Docs | agents/src/pipeline/pipeline_agent.ts | Speech & Audio Processing | livekit/livekit_composite | DeepWiki | Silero VAD plugin | LiveKit Docs

Correct me if I am wrong, that means, when the STT send a final event, the agent will not answer directly, it still need to wait for another "END_OF_SPEECH" event? right?

You’re absolutely right! When the STT sends a final event, the agent doesn’t jump in right away. Instead, it waits for the Silero VAD to trigger an

END_OF_SPEECH

event, which happens after the set silence duration (usually 0.55s). This way, the speech segment is fully processed before the agent chimes in. Hope that clears things up!

That means, I need to wait 0.1 + 0.55 to get the response?

Yes, with the default settings, you’d typically wait for the STT’s final event (0.1s) plus the Silero VAD’s silence duration (0.55s). So, all in all, it adds up to about 0.65 seconds before you get a response. Hope that helps!

the 0.55s is not Silero? right?

The 0.55s silence duration is actually a parameter of Silero VAD, called the

min_silence_duration

. This is basically the amount of time Silero waits to be sure the speech has ended before it triggers the

END_OF_SPEECH

event. Hope that clears things up!

I am a little confused, will the Silero only send the speech, or it stills wait before the agent answering?

Silero VAD doesn’t directly decide when the agent answers. Instead, it listens to the audio and sends signals like

START_OF_SPEECH

and

END_OF_SPEECH

. Usually, the agent waits for the

END_OF_SPEECH

event before jumping in, making sure the person has finished talking. So, the timing of the agent’s response really depends on both the STT’s final event and how Silero’s silence duration settings are set up.