You can specify customer caller sound when the order is announced to be ready.
Either you can use own Sound Editing tool or you can generate with the following method:
This is online document
https://docs.google.com/document/d/1bHYA2M5OjlEKXmHZLtdD3kXw7_7nKH9vf-RT42d4z4E/edit?usp=sharing