> ## Documentation Index
> Fetch the complete documentation index at: https://dialnexa.com/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# Latency Turn Taking And Interruptions In DialNexa

> Understand DialNexa latency, turn taking, interruptions, Response Eagerness, Deepgram Flux, Soniox, Audio Cache, fallback LLMs, and function latency in Voice AI calls.

Latency and turn taking decide whether a DialNexa Voice AI call feels natural. A good agent hears enough caller speech, replies quickly enough, avoids talking over people, and recovers when callers interrupt.

<Tip>
  A half-second pause can feel polite. A five-second pause feels like the call fell into a spreadsheet.
</Tip>

## The Live Call Timing Chain

Every response passes through a chain. The slowest link becomes the caller's experience.

| Stage          | What happens                                               | Common delay source                                               |
| -------------- | ---------------------------------------------------------- | ----------------------------------------------------------------- |
| Caller audio   | Phone, SIP, or web audio reaches DialNexa.                 | Poor network, low-volume caller, noisy room, or telephony bridge. |
| Speech to text | Deepgram or Soniox converts audio into text.               | Endpointing, language fit, noise, and interruption handling.      |
| LLM reasoning  | OpenAI, Google, or Groq produces the next reply or action. | Long prompt, slow model, function call, or fallback delay.        |
| Text to speech | ElevenLabs or Cartesia turns text into audio.              | Voice model latency, long responses, cache miss.                  |
| Playback       | Audio streams back to the caller.                          | Phone path, bridge delay, interruption handling.                  |

## Provider Choices That Affect Timing

| Provider or feature          | Timing effect                                                                    | Use when                                                                                |
| ---------------------------- | -------------------------------------------------------------------------------- | --------------------------------------------------------------------------------------- |
| Deepgram Flux (English only) | Fast English turn lifecycle signals. Good baseline for most English deployments. | English calls are your primary use case.                                                |
| Soniox STT RT v5             | Response Eagerness can tune how quickly the agent replies.                       | Hinglish or Hindi-English calls need a patient but responsive listener.                 |
| Groq fallback LLM            | Can reduce response delay when the primary model is slow.                        | You have measured LLM latency as the issue.                                             |
| Audio Cache                  | Reduces repeated text-to-speech startup time.                                    | The agent repeats exact phrases across calls.                                           |
| Custom functions             | Can pause the conversation while waiting for your API.                           | Only when the action is necessary before the agent can continue.                        |
| Web call provider warmup     | Returns the browser websocket while provider warmup continues in the background. | Web calls should start without waiting for every provider connection to finish warming. |

## Settings That Change Timing Directly

| Setting                  | Where it lives                      | Practical note                                                                              |
| ------------------------ | ----------------------------------- | ------------------------------------------------------------------------------------------- |
| Response Eagerness       | Speech Settings for Soniox.         | Moves the agent between patient and eager turn handling.                                    |
| Fallback LLM delay       | Model settings popover.             | Defaults to 500 ms when no saved value exists.                                              |
| Predictive preprocessing | Model settings for non-flow agents. | Pre-generates likely responses between turns when the next line is predictable.             |
| Audio Cache              | Speech Settings.                    | Helps only when text and voice configuration repeat.                                        |
| End call on silence      | Call Settings.                      | Prevents endless silence, but an aggressive value can end calls while callers are thinking. |

<img src="https://mintcdn.com/dialnexa/O6bVvssz6DpTKOa0/images/documentation/screenshots/model-settings-popover.jpg?fit=max&auto=format&n=O6bVvssz6DpTKOa0&q=85&s=62f2016b78640338b145e489d9ef4e9d" alt="DialNexa model settings popover showing LLM temperature, fallback LLM, fallback delay, and predictive preprocessing." style={{ width: '100%', maxWidth: '1100px', margin: '8px 0 24px', border: '1px solid #e5e7eb', borderRadius: '6px' }} width="1710" height="985" data-path="images/documentation/screenshots/model-settings-popover.jpg" />

## Diagnose Timing Problems

| Symptom                                           | First places to inspect                                                                                          |
| ------------------------------------------------- | ---------------------------------------------------------------------------------------------------------------- |
| Agent answers too early                           | Response Eagerness, transcript boundary, caller pause length, welcome message length.                            |
| Agent talks over caller                           | Transcriber choice, interruption behavior, audio overlap, prompt style.                                          |
| Agent waits too long                              | LLM latency, custom function latency, voice synthesis, cache misses, endpointing.                                |
| Call ends while caller is thinking                | Silence timeout, reminder interval, prompt pacing, caller environment.                                           |
| First sentence is fast but later replies are slow | LLM or function latency, not the welcome message.                                                                |
| Repeated phrases are slow                         | Audio Cache disabled, phrase variation, or voice model delay.                                                    |
| Web call creation fails before connection         | Agent version, wallet, provider readiness, or Speech session creation. A real creation failure can return `502`. |
| Agent speech has gaps mid-sentence                | TTS segmenting, provider latency, or playback ordering. Review recording and provider choice.                    |

## A Practical Tuning Order

<Steps>
  <Step title="Listen before editing">
    Start with the recording. Transcript text alone cannot show silence, overlap, breathing room, or whether the caller was interrupted.
  </Step>

  <Step title="Check transcript boundaries">
    See whether the caller's final words appear before the agent responds. If not, tune transcription and response timing first.
  </Step>

  <Step title="Shorten the agent response">
    Long welcomes and long answers increase the chance of overlap. A concise line often beats a philosophical paragraph.
  </Step>

  <Step title="Tune one technical setting">
    Adjust Response Eagerness, transcriber, fallback LLM, Audio Cache, or silence timeout one at a time.
  </Step>

  <Step title="Retest with deliberate interruptions">
    Ask the test caller to interrupt, correct themselves, pause, and answer with short phrases.
  </Step>
</Steps>

## Common Timing Traps

<AccordionGroup>
  <Accordion title="Blaming the voice when the custom function is slow">
    If the agent is waiting for an API response, voice speed will not fix it. Check function latency and timeout behavior.
  </Accordion>

  <Accordion title="Setting fallback delay too low">
    A very low fallback delay can race models unnecessarily. Start with a measured delay and inspect which model wins.
  </Accordion>

  <Accordion title="Making silence timeout too aggressive">
    People think, search, ask someone nearby, or look up details. Give them enough space.
  </Accordion>

  <Accordion title="Optimizing for speed before accuracy">
    A quick wrong answer is still wrong. Balance response speed with transcript quality and instruction following.
  </Accordion>
</AccordionGroup>

## Related Reading

<CardGroup cols={2}>
  <Card title="Speech Settings" icon="activity" href="/agent-settings/speech-settings">
    Tune Response Eagerness, Audio Cache, and Denoising Mode.
  </Card>

  <Card title="Speech To Text" icon="file-text" href="/voice-ai/speech-to-text-and-transcription">
    Compare transcriber timing behavior.
  </Card>

  <Card title="LLMs And Conversation Behavior" icon="brain" href="/voice-ai/llms-and-conversation-behavior">
    Understand fallback LLMs and model latency.
  </Card>

  <Card title="Call Detail Page" icon="panel-right" href="/monitoring/call-detail-page">
    Review evidence after a call.
  </Card>
</CardGroup>
