Can we change Aria's voice or name?

With Hire Pro, yes. In Settings → Hiring → How Aria speaks for you, under Her voice and name, choose the voice candidates hear (play a sample first) and the first name she introduces herself by. Only voices we have listened to and approved for screening calls are listed; more are being tested.

The name is a first name of 2 to 20 letters. It can't be a job title, or the name of anyone at your company, so candidates never think they spoke to a person. Whatever the name, she says she is an AI assistant at the start of every call. If your plan changes, candidates talk to Aria again, and your choice comes back with Hire Pro.