Chosen Solution

In iOS 12 they removed the earpiece option in voice memos. Now, in iOS 13 they appear to have removed the earpiece (Raise to Talk?) option in Siri, which makes me very sad. Is there any remaining or new method to test the proximity sensor and earpiece in stock iOS 13 without any third-party apps or without making a phone call?

I didn’t notice that yet, had no need to try out proximity sensor on iOs 13 so far. That’s not sad, it’s wretched. Spite by children, that’s what Apple has become..when a feature can be used for some testing purposes they prefer to disable it and leave it at their fanboys finding an undoubtedly excellent reason why it was THE RIGHTEOUS CHOICE..oh my..

Making a FaceTime call?

Yes, buy a cheap payg sim for £1. You do not have to credit it. Put it in the phone and then call that number from a regular phone. You can answer using the earpiece.