tall-ability-14645
03/21/2026, 2:12 PMtall-airline-16756
03/21/2026, 2:12 PMtall-airline-16756
03/21/2026, 2:13 PMtall-ability-14645
03/21/2026, 2:17 PMtall-airline-16756
03/21/2026, 2:17 PMturn_detection="stt" and you can tune silence and VAD thresholds for adaptive behavior.
• Deepgram (Flux): acoustic + semantic endpointing with tunable thresholds like eager_eot_threshold and `eot_threshold`; enable via STTv2 plugin and turn_detection="stt".
• Speechmatics: ML-based SMART_TURN endpointing (turn_detection_mode="SMART_TURN") and can integrate with external turn detection for more control.
• LiveKit Turn Detector: a multilingual, semantic turn detector that adapts VAD timeouts using transcript semantics — useful if you want model-agnostic, conversational-aware interruption handling.
Next steps I can help with:
• If you tell me which provider or runtime you’re planning to use (AssemblyAI, Deepgram, Speechmatics, OpenAI/GPT, or LiveKit-native), I can give configuration snippets and recommended parameter values for min_turn_silence, max_turn_silence, vad_threshold, or EoT thresholds.
• If you want, I can also explain how to combine a VAD plugin (Silero) with STT turn detection for the most responsive barge-in behavior.
Which provider or setup are you targeting?
Sources: AssemblyAI STT | LiveKit Documentation | Deepgram STT | LiveKit Documentation | Speechmatics STT plugin guide | LiveKit Documentation | Using a transformer to improve end of turn detection | LiveKit | Turns overview | LiveKit Documentation, with interactive elementstall-ability-14645
03/21/2026, 2:18 PMtall-airline-16756
03/21/2026, 2:18 PMmin_turn_silence, max_turn_silence, vad_threshold) for responsive interruption handling with OpenAI.
• Outline a design for hybrid approach (use Deepgram/AssemblyAI for alignment, then forward transcripts to OpenAI for understanding).
Which of those would help you most right now?
, with interactive elementstall-ability-14645
03/21/2026, 2:20 PMtall-airline-16756
03/21/2026, 2:20 PMfrom livekit.agents import AgentSession
from livekit.plugins import openai, silero
from livekit.plugins.turn_detector.multilingual import MultilingualModel
session = AgentSession(
# Use OpenAI STT plugin (example model name; pick the OpenAI model you have access to)
stt=openai.STT(model="gpt-4o-transcribe"),
# Silero VAD plugin for low-latency voice activity detection
vad=silero.VAD.load(),
# LiveKit multilingual semantic turn detector for adaptive endpointing
turn_detection=MultilingualModel(),
# Optional: tune these turn detector / VAD parameters if available on your runtime
# min_turn_silence=0.2,
# max_turn_silence=1.0,
# vad_threshold=0.5,
)
2) What each piece does
• `stt=openai.STT(...)`: Transcribes incoming audio. OpenAI handles the speech→text; turn semantics are handled separately.
• `vad=silero.VAD.load()`: Emits fast voice activity events so the system can react immediately to barge-in or sudden speech.
• `turn_detection=MultilingualModel()`: Uses transcript semantics to adapt VAD timeouts and decide end-of-turn, reducing false interruptions and allowing natural turn-taking.
3) Tuning recommendations
• Reduce min_turn_silence for more aggressive interruption (shorter silence before treating as end-of-turn).
• Increase max_turn_silence to avoid premature cutoffs on longer pauses.
• Set vad_threshold to balance sensitivity vs. noise (lower = more sensitive).
• Test combinations: VAD handles immediate barge-in; the turn detector confirms semantic completion to avoid chopping sentences.
4) Deployment notes
• Ensure the OpenAI STT plugin and turn-detector/VAD plugins are installed for your agent runtime.
• If you need word-level aligned timestamps (word alignment), OpenAI STT does not provide aligned transcripts in the sources checked — use an STT provider that supports alignment (AssemblyAI, Deepgram, Speechmatics) or a forced-alignment post-processing step.
• If you want, I can produce:
◦ A full runnable agent.py example with download/run instructions.
◦ Concrete parameter values to start testing (I’ll tailor them to your expected environment: quiet room vs noisy background, latency requirements, single speaker vs multi-party).
Which would you like next — a runnable example, or suggested parameter values for your environment?
Sources: OpenAI STT plugin guide | LiveKit Documentation | Silero VAD plugin | LiveKit Documentation | LiveKit turn detector plugin | LiveKit Documentation | Turns overview | LiveKit Documentation | Build a multilingual voice agent that automatically switches languages | Li..., with interactive elementstall-ability-14645
03/21/2026, 2:35 PMtall-airline-16756
03/21/2026, 2:35 PM'tuple' object has no attribute 'capabilities'). I’ll explain what’s happening, why it occurs, and give concrete fixes and checks you can run.
What the error means
• The interruption-detection code expects self.stt to be an STT instance object that has a capabilities attribute.
• Your call to inference.STT(model="deepgram/flux-general", language="en") appears to be returning a tuple instead of an STT instance. When the agent tries to access self.stt.capabilities, Python raises the AttributeError because tuples have no capabilities.
Most likely causes
• You imported/used the wrong constructor/API: inference.STT(...) in your environment may be returning a (model, options) tuple instead of a plugin instance.
• You may be using a string descriptor vs plugin class inconsistently (both are supported in different contexts).
• A version mismatch in your livekit-agents package could cause different return types.
Quick checks (run these to narrow it down)
1. Inspect the returned value immediately after instantiation:
from livekit.agents import inference
stt = inference.STT(model="deepgram/flux-general", language="en")
print(type(stt))
print(stt)
Expected: type should be a plugin STT class (not tuple). If you see tuple, that confirms the root cause.
1. If you used a string descriptor anywhere, try the string form instead:
• Use stt="deepgram/flux-general:en" in AgentSession (LiveKit will resolve it to the proper object internally).
Recommended fixes Option A — Use the plugin class directly (recommended for explicit control):
from livekit.agents import AgentSession
from livekit.plugins import deepgram, silero
from livekit.plugins.turn_detector.multilingual import MultilingualModel
session = AgentSession(
stt=deepgram.STT(model="flux-general", language="en"),
vad=silero.VAD.load(),
turn_detection=MultilingualModel(),
)
Option B — Use the string descriptor (works if you want the inference resolver to handle instantiation):
from livekit.agents import AgentSession
from livekit.plugins import silero
from livekit.plugins.turn_detector.multilingual import MultilingualModel
session = AgentSession(
stt="deepgram/flux-general:en",
vad=silero.VAD.load(),
turn_detection=MultilingualModel(),
)
Option C — If you must use inference.STT(...), confirm you imported the correct `inference`:
from livekit.agents import inference
# or check if you intended: from livekit.plugins import deepgram
If inference.STT is returning a tuple in your package version, switch to Option A or B.
Additional debugging steps
• Print the stack/type where error occurs to confirm the object class before the attribute access.
• Verify your installed package versions and upgrade if outdated:
◦ Ensure you have the latest livekit-agents and plugin packages.
• If you see tuple contents, examine them — sometimes it’s (descriptor, options) and you can adapt your code to pass only the expected piece, but prefer the plugin or string-descriptor approach above.
Notes about aligned transcripts / capabilities (relevant because the code checks capabilities.aligned_transcript)
• The agent code checks stt.capabilities.aligned_transcript to decide logic paths. If stt isn’t an object, the check fails.
• If you need aligned transcripts, Deepgram can provide alignment features; confirm the plugin instance reports capabilities.aligned_transcript = True after you instantiate correctly.
If you want, I can:
• Inspect the output of print(type(stt)) and the printed value you get and tell you the exact line to change.
• Provide a small runnable file (agent.py) using the plugin class that you can drop into your environment to verify everything works.
Which check would you like to run first — the print(type(stt)) debug or I should give a runnable example file using the plugin class?
Sources: OpenAI STT plugin guide | LiveKit Documentation | OpenAI TTS plugin guide | LiveKit Documentation | Text and transcriptions | LiveKit Documentation | examples/voice_agents | livekit/livekit_composite | DeepWiki | LiveKit turn detector plugin | LiveKit Documentation, with interactive elementstall-ability-14645
03/21/2026, 2:48 PMtall-airline-16756
03/21/2026, 2:49 PM