AI_coustics blocking pipeline (?)

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Hi all,

I’m seeing an intermittent but severe failure in a Python LiveKit Agents deployment and wanted to check whether anyone else has run into this.

Setup:

  • LiveKit Agents Python SDK 1.5.2
  • Python worker
  • ai-coustics noise cancellation enabled with the Quail model

What happens:

  • A session is running normally
  • The last normal log is typically something like the user beginning to speak
  • After that, there is a long gap with no STT events, no transcription events, and no downstream activity
  • Eventually the worker is killed by the supervisor with logs like:
    • process is unresponsive, killing process
    • exit code -10

What makes this concerning is that the failure appears to happen before STT is activated, so it looks like the audio/input pipeline is getting blocked upstream rather than a normal STT/LLM/TTS exception. There is no useful traceback when it happens.

Current hypothesis:
I suspect the issue may be related to ai-coustics Quail in the input pipeline, possibly blocking or stalling audio processing under some conditions. I’m removing ai-coustics for now to see whether the issue disappears.

Questions:

  1. Has anyone seen ai-coustics / Quail cause worker hangs or audio pipeline stalls in Python agents?
  2. Are there recommended timeout / watchdog / fallback patterns for the audio input path?
  3. If this is not likely ai-coustics, are there other parts of the pre-STT pipeline I should inspect first?

Any guidance would be really appreciated. This is intermittent but production-impacting because it causes the whole worker handling the session to die.