Interaction Mode: Full-Duplex, Listen-Only, Walkie-Talkie
2026-08-25
Scenario Overview
When interacting with the AI agent, there are three interaction forms that can be configured through the AdvancedConfig.CommunicationMode parameter when creating an agent instance:
| Interaction Form | Use Case | Common Scenarios |
|---|---|---|
| Full-Duplex Mode (Default) | Free conversation scenarios where users can speak at any time and the AI responds instantly. | AI voice call |
| Listen-Only Mode | Continuous speech-to-text scenarios where AI listens without responding. | Cloud-based speech recognition, AI interviews, user content summarization |
| Walkie-Talkie Mode | On-demand short-turn interaction where users press to speak and release to receive AI responses. | Temporary speaking in online meetings, privacy protection in AI hardware |
AI Agent Behavior Differences
| Dimension | Full-Duplex Mode | Listen-Only Mode | Walkie-Talkie Mode |
|---|---|---|---|
| User Speech Start/End Condition | Automatically detected by VAD segmentation | Automatically detected by VAD segmentation | Starts with StartListening, ends with StopListening; typically within 30 seconds |
| AI Speech Trigger | ✅ AI automatically replies after user finishes speaking ✅ Proactively speak via SendAgentInstanceTTS | ✅ Proactively speak via SendAgentInstanceTTS | ✅ AI automatically replies after listening ends ✅ Proactively speak via SendAgentInstanceTTS |
| ASR Callback | Result is sent after user finishes speaking | Every result matching segmentation rules is sent; a long listening session may generate multiple callbacks | Result is sent after StopListening |
| LLM Request | Requests LLM to generate a reply | Does not request LLM | Requests LLM to generate a reply |
| TTS | Broadcasts AI reply content | Does not automatically broadcast | Broadcasts AI reply content |
| Subtitles | Sent normally | Sent normally | Sent normally |
Interaction Mode Switching
- Full-Duplex Mode (0) and Listen-Only Mode (1) can be switched between each other. The switch takes effect from the next user speech.
- Walkie-Talkie Mode (2) does not support switching to other modes.
Implementation Steps
Prerequisites
- Enable AI Agent service and complete the basic process according to Quick Start Voice Call.