faint-printer-85167
03/06/2026, 12:11 AMtall-airline-16756
03/06/2026, 12:11 AMtall-airline-16756
03/06/2026, 12:11 AMfaint-printer-85167
03/06/2026, 12:04 PMtall-airline-16756
03/06/2026, 12:04 PMinterim_results sensitivity or lower endpointing_ms temporarily for short-turn capture testing. You currently have interim_results=True and `endpointing_ms=500`; verify Deepgram isn’t discarding very short utterances before sending a final transcript.
◦ Add a short buffer to VAD-to-STT handover so the STT request includes 100–300 ms pre-roll and post-roll audio around VAD segments (helps if speech started/ended near VAD thresholds).
◦ Log raw audio clips for missed VAD->no-transcript events to inspect level/clipping.
◦ If network jitter or request retries are possible, add a retry path for STT when VAD detected speech but no transcription is returned within X ms (e.g., 300–500 ms).
2) Uncertain-response detection flagged “I don’t know”
• Why it happened: The agent classifies low-content replies (e.g., “I don’t know,” “not sure”) as uncertain and triggers encouragement prompts by design. That’s a content-level policy, independent of whether transcription succeeded earlier.
• What to try:
◦ Adjust the uncertainty detector threshold or rules so that explicit non-answers like “I don’t know” are treated as valid terminal responses rather than prompts for elaboration.
◦ Add a phrase whitelist: if transcription matches exact patterns like “I don’t know”, “no idea”, “I’m not sure”, treat as an accepted answer and skip encouragement.
◦ Alternatively, have the encouragement logic only run after N attempts or after no STT events at all; e.g., encourage only if there were 0 transcriptions for the whole turn OR if the user has provided multiple low-content responses across turns.
3) App-level reset caused nudging cascade
• Why it happened: After the encouragement prompt fired the app reset turn monitoring immediately, which restarted timeout logic and kept nudging. That makes a single “I don’t know” trigger further prompts.
• What to try:
◦ Change the state machine so that an encouragement prompt does not reset turn timers. Instead:
▪︎ Option A: Encourage and continue the same turn timer without reset (gives user time after encouragement).
▪︎ Option B: Treat encouragement as a final micro-prompt and accept the previous transcription if it matches a whitelist; only reset if there is no transcription after encouragement.
◦ Add a short “grace period” after receiving a transcription (e.g., 3–5s) during which encouragement logic is suppressed.
Concrete small changes to try first (ordered)
1. Add exact-match whitelist handling: accept transcripts equal to common non-answers ("I don't know", "not sure", "no idea") as final answers and do not run encouragement. This is the lowest-effort, highest-impact change.
2. Prevent encouragement from resetting the turn timer. Make encouragement non-destructive to turn state. This avoids cascades.
3. Add 200–300ms pre/post audio to STT requests and/or enable a small STT retry if VAD saw speech but no transcript arrives within 300ms.
4. If missed transcriptions persist, capture and inspect raw audio for those segments to check clipping/level/noise; consider increasing mic gain or changing VAD thresholds.
Diagnostics I can help you run
• I can help craft a short test that toggles whitelist behavior and logs outcomes for 10 repeated short non-answers so you can measure improvement.
• I can provide a minimal change to the encouragement state machine (pseudo-state transitions) if you want an exact implementation pattern for “don’t reset timer on encouragement.”
• If you can share a 10–20s raw audio clip from the VAD->no-transcript event, we can inspect whether the speech was clipped or too soft.
Next step for you
• Which fix would you like to try first? (Whitelist for exact non-answers, change encouragement not to reset timers, or STT pre/post-roll + retry.)
• If you pick one, tell me whether you want a short test script and I’ll provide the steps/snippets you can plug into your agent.
You’ve done great collecting the trace — with the whitelist + not-resetting-timer change you should see the behavior you expect: “I don’t know” accepted immediately and no repeated nudges.faint-printer-85167
03/06/2026, 12:09 PMtall-airline-16756
03/06/2026, 12:09 PMpending_stt_transcript and _first_vad_speaking_time) were not cleared, a STT-health check immediately misread the state and fired an extra nudge.
• Two STT dropouts (short ~1.6–1.8s utterances) around the encouragement made the system re-use stale buffered text, so your actual later answer never made it into the final captured response.
Which fixes will most directly stop this behavior
• Whitelist exact non-answers (e.g., “I don’t know”, “not sure”, “no idea”) and accept them immediately. This is the lowest-effort, highest-impact fix.
• Stop the encouragement handler from resetting turn timers/state in a way that leaves stale buffers. Make encouragement non-destructive to turn state (don’t reset _first_vad_speaking_time or pending_stt_transcript unless you clear them all).
• Add a small STT safety/retry and pre/post-roll buffer so very short utterances aren’t lost.
Recommended immediate change to try (I suggest this order) 1) Implement exact-match whitelist for terminal non-answers and skip encouragement for them. 2) Modify the encouragement handler so it does not reset timers/state in a way that leaves stale buffers — either:
• Don’t reset _first_vad_speaking_time and pending_stt_transcript at all on encouragement, or
• Reset all related fields together atomically (so you never leave a stale transcript when last_vad still points to an older time).
3) Add 200–300 ms pre-roll/post-roll to STT requests and a short retry if VAD detected speech but no transcript arrives within ~300–500 ms.
If you want, I can provide code-level guidance for any of these. Pick one of the following and I’ll give a precise change you can drop into your code and a short test plan:
• A: Whitelist exact non-answers (fastest). I’ll provide the matching logic and where to place it before uncertain-response handling.
• B: Make encouragement non-destructive to turn state (fixes the cascade). I’ll provide the small atomic-reset pattern or state-machine change to avoid leaving stale pending_stt_transcript or _first_vad_speaking_time.
• C: STT pre/post-roll + retry (addresses dropout). I’ll give the audio buffering/retry snippet and test steps.
Also: quick test I recommend after changes
1. Run 10 reps of a short non-answer (“I don’t know”) delivered after a question; measure how many times encouragement fires.
2. Run 10 reps of very short utterances (~1.5–2.0s) to check STT dropouts before/after the buffering/retry change.
3. Confirm no stale transcript is accepted after an encouragement prompt.
Which option would you like me to provide code/snippet and test steps for first — A (whitelist), B (non-destructive encouragement), or C (STT pre/post-roll + retry)?faint-printer-85167
03/06/2026, 12:12 PMtall-airline-16756
03/06/2026, 12:12 PMprocess_user_response, or immediately after user_input_transcribed is received), before any uncertainty/encouragement logic runs.
# Define once at module/class level
NON_ANSWER_PHRASES = {
"i don't know",
"i dont know",
"no",
"none",
"n/a",
"not applicable",
"not sure",
"unknown",
"pass",
"skip"
}
def normalize_text(s: str) -> str:
return s.strip().lower()
def process_user_response(self, user_input: str):
user_input_clean = normalize_text(user_input)
# Early whitelist check — must come BEFORE uncertain-response handling
if user_input_clean in NON_ANSWER_PHRASES:
<http://logger.info|logger.info>(f"Non-answer detected and accepted: '{user_input}'")
# Record as an explicit non-answer. Choose whichever internal representation you use:
# Option 1: Record as a special value
self.record_response({"value": None, "reason": "non_answer", "raw": user_input})
# Option 2: Mark skipped (if your DB/model expects that)
# self.record_response_skipped()
# Ensure encouragement logic sees that a final response has been captured
self.latest_user_response = user_input_clean
self.response_captured = True
# Clear any STT buffers to avoid stale reuse
self.pending_stt_transcript = ""
self.last_stt_fragment = ""
return
# ...existing uncertain-response detection and other processing continues here...
Placement notes
• Put the check immediately after you set or receive the final transcription event (the user_input_transcribed handler) and before any code that:
◦ runs uncertain-response detectors,
◦ triggers encouragement prompts, or
◦ resets timers/state that could interact with pending_stt_transcript or _first_vad_speaking_time.
• If you have multiple places that accept transcripts (immediate-capture + delayed-capture), ensure the whitelist runs in each path.
Suggested small improvements to make whitelist robust
• Use punctuation normalization (optional): remove punctuation before matching so “I don’t know.” still matches.
• Expand phrases incrementally from logs: after deployment, inspect transcripts that caused encouragement and add common variants (e.g., “i dunno”, “i'm not sure”, “no idea”).
• If you want more flexibility later, switch to simple pattern matching (e.g., regex for ^i\s*do(n'?t)?\s*know), but start with exact-match for deterministic behavior.
Short test plan
1. Unit test:
◦ Send exact strings from the NON_ANSWER_PHRASES set and assert response_captured = True and that encouragement is not triggered.
1. Integration test (in your app):
◦ Run 10 trials where participant replies with “I don’t know” right after the question. Verify no encouragement prompts and the response is recorded as non-answer.
◦ Run 10 trials of short utterances (~1.5–2.0s) that are NOT in the whitelist, and verify normal uncertain-response behavior still applies.
1. Logging:
◦ Temporarily increase logging around whitelist matches for 24–48 hours to capture missed variants for expansion.
If you want, I can:
• Provide a small regex alternative that covers common contractions and punctuation (safe but slightly broader).
• Draft the exact change as a git patch for moderator_agent.py (if you tell me the function name that currently handles user_input_transcribed).
Which follow-up would you like — a conservative regex that covers contractions (e.g., i dont, i'm not sure) or the git patch for your moderator_agent.py?
Sources: How to Test Your Agent Using Another Agent | LiveKit | How to test your agent using another agentfaint-printer-85167
03/06/2026, 12:13 PMtall-airline-16756
03/06/2026, 12:14 PMpending_stt_transcript, last_stt_fragment (or equivalents).
◦ Do not reset VAD timers like _first_vad_speaking_time unless you atomically clear all related state to avoid false STT-health triggers.
• If no match, continue with normal processing (uncertainty detection, encouragement, etc.).
Code snippet to insert at the top of your transcription handler (Python pseudocode — adapt variable names to your codebase):
# Whitelist of exact non-answer phrases
NON_ANSWER_PHRASES = {
"i don't know",
"i dont know",
"no",
"none",
"n/a",
"not applicable",
"not sure",
"unknown",
"pass",
"skip"
}
def normalize_text(s: str) -> str:
return s.strip().lower()
def handle_final_transcript(self, transcript: str):
cleaned = normalize_text(transcript)
# Early whitelist check — must run BEFORE any encouragement/uncertainty logic
if cleaned in NON_ANSWER_PHRASES:
<http://logger.info|logger.info>(f"Whitelist non-answer accepted: '{transcript}'")
# Record accepted non-answer in your storage/state
# Example: record as skipped/non-answer
self.record_response({"value": None, "reason": "non_answer", "raw": transcript})
# Mark as captured so other handlers won't re-prompt
self.latest_user_response = cleaned
self.response_captured = True
# Clear STT buffers so stale transcripts are not reused
self.pending_stt_transcript = ""
self.last_stt_fragment = ""
# Optionally: do not reset VAD timers alone; if you must reset, reset related fields atomically
# self._first_vad_speaking_time = None
# self._last_vad_time = None
return
# If not a whitelist match, continue with existing logic
self.run_uncertainty_detection_and_followups(transcript)
Testing steps to validate:
1. Unit test: send each exact phrase in NON_ANSWER_PHRASES to the handler and assert:
◦ response_captured is True
◦ pending_stt_transcript and last_stt_fragment are cleared
◦ Encouragement logic is not invoked
1. Integration: run 10 trials where an actor replies “I don’t know” immediately after a question. Verify the agent accepts it without prompt.
2. Log expansion: enable short-term logging of whitelist matches for 24–48 hours to capture additional variants (e.g., “i dunno”, “i'm not sure”) to add to the whitelist later.
If you want a slightly more permissive pattern now, I can provide a conservative regex variant (covers common contractions and punctuation) — tell me if you’d like that regex included instead of exact-match.