Why is my brand new phone intermittently cutting off my calls with an ear piercing screech?

[Android Central Question]

I got a brand new Motorola G7 2 days ago. I am now on my second one, because right in the middle of a conversation, it decided to emit an extremely loud noise. This noise is kind of like the person on the other end is holding down a button on their phone, but it doesn't stop. It will go on until I end the call. During this time, it is like the other party isn't even there, I can hear nothing else. It has happened during 2 conversations on the first phone (only had it for around 24 hours), and once on the replacement.

 

[Rukbat]

Sounds more like something coming from your carrier. Feedback, maybe.