### Answer You can override an agent's voice model when creating a phone call using the

agent_override

parameter [(1) ]() [(2) ]() . Based on the documentation and community discussions, here's how to structure your request:

javascript
const call = await client.call.createPhoneCall({
    to_number: "+1234567890",
    from_number: "+0987654321",
    override_agent_id: "your_agent_id",
    agent_override: {
        agent: {
            voice_id: "minimax-Camille",
            voice_model: "sonic-3"
        }
    }
}) ;

**Important note**: Make sure the

voice_id

and

voice_model

are compatible. For example, don't pair a Cartesia voice with a Minimax model - they need to match their respective TTS providers [(1) ]() . The available voice models include:

eleven_turbo_v2

,

eleven_flash_v2

,

eleven_turbo_v2_5

,

eleven_flash_v2_5

,

eleven_multilingual_v2

,

eleven_v3

,

sonic-3

,

sonic-3-latest

,

tts-1

,

gpt-4o-mini-tts

,

speech-02-turbo

,

speech-2.8-turbo

, and

s1

[(3) ]() . For inbound calls with custom telephony, you can also override the voice settings in your inbound webhook response [(2) ]() .

​ To learn more, see the sources I considered: [[1] Minimax TTS is not outputing audio !](https://discord.com/channels/1186424376300679209/1476976755595018460) [[2] Override agent's configurations before making a call.](https://discord.com/channels/1186424376300679209/1315610729172434945) [[3] Update Voice Agent](https://docs.retellai.com/api-references/update-agent) ​

Feel free to tag @AI Evy with additional questions. I also appreciate feedback, it helps me improve.

### Answer Based on community discussions, there have been reported issues with ElevenLabs voices [(1) ]() [(2) ]() . Voice Model Compatibility Issues [(1) ]() : - When setting

voice_model

to

eleven_turbo_v2_5

via API, some voices are incompatible with this model - Attempting to revert to default models like

eleven_turbo_v2

can result in compatibility errors - The issue is particularly noticeable with OpenAI voices - To reset to default behavior (Auto) , you need to send

null

for

voice_model

, but this must be done in a separate API call before changing the

voice_id

Voice Instability Issues [(2) ]() : - Users reported voices being highly unstable and switching to other voices and languages mid-conversation - Voices randomly speaking in different languages (e.g., French when configured for English) - Pronunciation changing from one call to another - English American accents switching to British accents mid-conversation Suggested Troubleshooting : - Avoid selecting multilingual if not needed - Use GPT-4 or other latest models - Test prompts multiple times - Contact support@retellai.com directly if issues persist These reports come from Discord community discussions and may not represent current platform status. For the most up-to-date information on any ongoing issues, I recommend checking with Retell AI support directly.

​ To learn more, see the sources I considered: [[1] Issue when sending

voice_model

parameter

elevenlabs_turbo_v2_5

](https://discord.com/channels/1186424376300679209/1367836412778512545) [[2] Issues with Elevenlabs?](https://discord.com/channels/1186424376300679209/1363908289133412483) ​

Feel free to tag @AI Evy with additional questions. I also appreciate feedback, it helps me improve.