genetic-orange•2d ago

Very slow and robotic voices

Dear folks, I often have the problem of “very slow and robotic voices” here. After a certain point, the voice becomes completely distorted. there is no clear pattern when this happens. Sometimes 10 calls everyhing is fine and sometimes I have 5 calls in a row where this happens. Model used: GPT5 oder 5.1 Transscriber: Deepgram or AssemblyAI is used as the transcriber. The agents’ language is German. Voices: 11labs or Cartesia Logs: The logs show no errors at all. Token size is currently at 1250. Call id: 019aea11-1582-7000-82e3-07d38296a372 Starting at around 1m2s Any suggestions are welcome. Currently we need to take our VAPI Agents offline as this is unacceptable. Could it be the latency of the llm oder something VAPI internally. I can provide recordings for sure.

1 Reply

Vapi Support Bot•2d ago

Suggestion: Try switching your voice provider to Azure or OpenAI TTS for your German agents, as this often resolves "robotic" or distorted speech issues. In your Vapi dashboard, go to your assistant's Voice section and select a different provider (e.g., Azure), then save and test:

# Example: Change voice provider in dashboard
1. Navigate to Assistants > [Your Assistant]
2. Under Voice, select Provider: Azure
3. Choose a German voice (e.g., de-DE-KatjaNeural)
4. Click Save and test a call

# Example: Change voice provider in dashboard
1. Navigate to Assistants > [Your Assistant]
2. Under Voice, select Provider: Azure
3. Choose a German voice (e.g., de-DE-KatjaNeural)
4. Click Save and test a call

This quick change can help you determine if the issue is provider-related. For more details, see the debugging documentation. Source: - Debugging Documentation

⤵️ Mention @Vapi Support Bot for follow-ups 🐥

Very slow and robotic voices

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