How Language Detection Decides Which Language to Speak
If you've enabled multilingual support on your AI receptionist, the AI can automatically detect which language a caller is speaking and respond in that language. Here's how the detection works.
What language detection does
When a caller speaks in the first few seconds of the call (after the initial greeting), the AI listens and attempts to identify the language. If the detected language matches one of your configured additional languages, the AI switches to that language for the rest of the call.
The primary language
Your AI receptionist always starts in your primary language. The opening greeting, the first thing callers hear, is always in the primary language. Language detection applies from the caller's first response onward.
If the caller responds in the primary language, nothing changes — the conversation continues in the primary language.
When detection switches languages
If the caller responds in a supported secondary language:
- The AI detects the language.
- The AI switches to that language for its responses.
- The conversation continues bilingually from the AI's side.
Language detection only works for languages you've configured as additional languages in the AI's Voice & Languages settings. If a caller speaks a language not in your configuration, the AI will remain in the primary language.
Language detection requires additional languages configured
Language detection must be enabled in your Voice & Languages settings, and you must have at least one additional language configured. If no additional languages are added, the language detection toggle cannot be enabled.
See AI Agent Voice & Languages for the setup steps.
Accuracy of detection
Language detection is generally accurate when:
- The caller speaks clearly and uses a few words of the language.
- The caller doesn't mix languages heavily in their first response.
If a caller speaks a mixed sentence (code-switching), the detection may default to one language or the other. The AI will handle this gracefully and continue the conversation.
💡 Tip: Language detection works best when you configure it for languages you actually need to serve. If your customer base speaks primarily English and Mandarin, configure those two — don't add languages you don't need, as it adds unnecessary complexity.
⚠️ Important: Language detection fires after the caller speaks. The initial greeting is always in your primary language. If you want callers to know they can respond in another language, include a brief note at the end of your greeting (e.g. "You may also speak in [language].").