It doesn't have to be. You can configure your bot to great the user. E.g. "Aleksandra is not available at the moment, but I'm her AI assistant to help you book

It doesn't have to be. You can configure your bot to great the user. E.g. "Aleksandra is not available at the moment, but I'm her AI assistant to help you book a table. How may I help you?" So you're telling the caller that it is an AI, and yet you can have a pleasant background audio experience.