I have a case where Confidence Threshold may not have worked correctly. The configuration is under Assistants, inside 'Transcriber' section, when 'Deepgram' is selected. The description of the configuration in the UI is > Confidence Threshold > Transcripts with a confidence score below this threshold will be filtered out. I have an assistant using Deepgram Flux General English EN with a confidence Threshold of 0.5. During a call, a transcript turn was given a confidence value of 0.2169

{
  "id": "log-56",
  "level": 30,
  "time": 1763194235360,
  "timestamp": 1763194235360000000,
  "severityText": "INFO",
  "severityNumber": 9,
  "body": "Deepgram flux final transcript",
  "attributes": {
    "category": "transcriber",
    "callId": "019a8690-ab8e-7dd4-abc4-0399690c00bc",
    "orgId": "5143d15b-8d5a-4df0-882d-daecf9ec66a1",
    "provider": "deepgram",
    "channel": "user",
    "transcript": "The mature post.",
    "confidence": 0.2169,
    "numWords": 3,
    "duration": 1486,
    "latency": 479
  }
}

However, that doesn't seem to impact what was sent to the LLM

{
  "id": "log-59",
  "level": 30,
  "time": 1763194235363,
  "timestamp": 1763194235363000000,
  "severityText": "INFO",
  "severityNumber": 9,
  "body": "Google HTTP request",
  "attributes": {
    "category": "model",
    "callId": "019a8690-ab8e-7dd4-abc4-0399690c00bc",
    "orgId": "5143d15b-8d5a-4df0-882d-daecf9ec66a1",
    "provider": "google-aistudio",
    "model": "gemini-2.5-flash",
    "request": {
      "model": "gemini-2.5-flash",
      "messages": [
        {/* truncated */},
        {
          "role": "user",
          "parts": [
            {
              "text": "The mature post."
            }
          ]
        }
      ],
      /* truncated */
      }
    }
  }
}

I'm expecting the LLM to know that the transcription 'The mature post' was low confidence, or at least filtered out. Could you explain how the confidence configuration is meant to work?

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Call ID is 019a8690-ab8e-7dd4-abc4-0399690c00bc

Hi there — thanks for the call ID. We checked the logs and found that the confidence threshold only applies to transcripts with 2 words or fewer. Since your transcript (“The mature post.”) has 3 words, it wasn’t filtered even though its confidence was low. This feature was originally meant to block short noise artifacts, not longer transcripts.

Great to know! Thank you

Glad we could help!