> ## Documentation Index
> Fetch the complete documentation index at: https://docs.itellico.ai/llms.txt
> Use this file to discover all available pages before exploring further.
# Call Quality & Latency
> Diagnose and fix audio quality, latency, and turn-taking issues in voice calls
This guide covers diagnosing and resolving audio quality, latency, and conversational flow issues.
## Diagnosing Latency
Response latency is the time between when a caller finishes speaking and when the agent starts replying. The agent editor toolbar shows estimated latency for your configuration.
### Latency Breakdown
Total latency = Transcription + AI Model + Voice Synthesis + Network
| Component | Typical Range | How to Optimize |
| ------------------- | ------------- | ---------------------------------------------------------------- |
| **Transcription** | 200-700ms | Use Deepgram Nova-3 (\~300ms) over Azure Speech (\~500-700ms) |
| **AI Model** | 300-2000ms | Use faster models (Groq, GPT-4.1 Nano) for speed-critical agents |
| **Voice Synthesis** | 100-500ms | Use low-latency providers (Cartesia is fastest) |
| **Network** | 50-200ms | Phone calls add more network hops than web calls |
### When Latency Is a Problem
* **Under 1 second**: Excellent — feels like a natural conversation
* **1-2 seconds**: Acceptable for most use cases
* **2-3 seconds**: Noticeable — consider optimizing or adding thinking sounds
* **Over 3 seconds**: Poor experience — take action now
If your response time consistently exceeds 3 seconds, follow the steps below immediately. Check [status.itellico.ai](https://status.itellico.ai) first for any ongoing platform issues.
### Quick Fixes for High Latency
1. **Switch to a faster model** — Go to General → Thinking and try Balanced or Fast presets
2. **Enable thinking sounds** — General → Sounds → Thinking Sounds (Expert Mode) fills processing time with keyboard audio
3. **Enable smart filler** — General → Sounds → Smart Filler (Expert Mode) generates contextual filler phrases
4. **Use a faster voice provider** — Check [Supported Providers](/reference/supported-providers) for latency benchmarks
5. **Simplify your prompt** — Shorter prompts process faster
6. **Adjust VAD turn detection** — [VAD settings](/build/advanced/vad-turn-detection) can have a significant impact on perceived response timing
***
## Turn-Taking Issues
### Agent Talks Over the Caller
**Symptoms:** Agent starts speaking while the caller is still talking, or responds too quickly after brief pauses.
**Fix:**
1. Open [VAD Turn Detection](/build/advanced/vad-turn-detection) settings
2. Switch to a more **Patient** response timing preset
3. In Expert Mode, increase **Silence before responding** (e.g., from 300ms to 500ms)
4. Enable **AI Turn Detection** (Expert Mode) for smarter end-of-turn detection
### Agent Waits Too Long to Respond
**Symptoms:** Awkward silences after the caller finishes speaking.
**Fix:**
1. Switch to a more **Responsive** timing preset
2. In Expert Mode, reduce **Silence before responding**
3. Check if **AI Turn Detection** is causing delays — try toggling it off
4. Switch to a faster AI model
### Caller Can't Interrupt the Agent
**Symptoms:** Caller speaks but the agent continues its response without stopping.
**Fix:**
1. In Expert Mode, enable **Allow Interruptions**
2. Reduce **Speech duration to trigger interrupt** (how long the caller must speak to interrupt)
3. Reduce **Minimum words to interrupt** threshold
***
## Audio Quality Issues
### Robotic or Unnatural Voice
1. Try a different [voice](/build/voice-speech/select-voice) — some voices sound better for conversational use
2. Adjust [voice settings](/build/voice-speech/voice-settings) (Expert Mode) — tweak stability, similarity, and style parameters
3. Lower the Response Style (temperature) setting — higher values can produce less consistent speech patterns
### Echo or Feedback
* This typically occurs on web calls. Check that the caller's browser has echo cancellation enabled
* Reduce ambient sound volume if using background audio
* Test with headphones to isolate the issue
### Muffled or Unclear Speech
1. Check your [transcriber](/build/voice-speech/transcriber) selection — Deepgram Nova-3 has the best general accuracy
2. Add [custom pronunciations](/build/voice-speech/custom-pronunciations) for frequently misheard terms
3. In Expert Mode, add [keywords](/build/voice-speech/transcriber) to boost recognition of specific terms
### Phone vs Web Quality Differences
Phone calls go through additional compression and network hops, which can affect quality:
* Always test with real phone calls before launching — web simulator results may differ
* Phone networks add 50-200ms of latency that web calls do not have
* Codec compression can affect voice quality — some voice providers handle this better
***
## Silence Handling
### Agent Does Not Respond When Caller Goes Silent
Configure [Inactivity Timeout](/build/advanced/inactivity-timeout-settings):
1. Enable **Silence Reminders** to prompt the caller after a period of silence
2. Set **Max Call Duration** to end calls that run too long
3. In Expert Mode, configure reminder timing (delay and max count)
### Agent Hangs Up Too Quickly
1. Increase **Max Call Duration** (default may be too short for your use case)
2. Check that **Allow AI to Hang Up** is not ending calls prematurely
3. Review your prompt — remove language that tells the agent to end calls aggressively
***
## Testing Methodology
1. **Start with web calls** — fastest iteration cycle, no phone network variables
2. **Move to phone calls** — test real network conditions, AMD behavior, and voice quality
3. **Test from different environments** — quiet office, noisy space, mobile, landline
4. **Compare models** — try the same conversation with different AI models to find the best speed/quality tradeoff
5. **Review conversation timelines** — check tool execution times and knowledge retrieval latency
## Next Steps
Configure response timing and interruptions
Select the right model for speed vs quality
Fill processing pauses with audio
Find quick fixes for common problems