----------------------------- **While I generate an answer, here are some sources that might be helpful**: * [Get Call]() * [List Calls]() * [Create Assistant]() * [List Assistants]() -----------------------------

### Answer It seems there have been reports of issues when integrating Eleven Labs' voice with Vapi, particularly resulting in a 400 error during calls. This problem was discussed in a Discord forum, where a developer experienced similar issues when trying to use Eleven Labs' voice in their application, leading to unsuccessful call attempts [(1)]() . To minimize such issues, it could be beneficial to double-check the assistant's configuration, especially the voice provider and voice ID parameters. Additionally, ensuring that the assistant and call configurations follow the correct formats as outlined in the Vapi documentation could help prevent unexpected errors. If the problem persists, it may be related to a specific bug or configuration issue that requires further investigation. Given the nature of the issue, it's advisable to review the assistant and call setup thoroughly against the provided documentation and examples.