iPhone 7 microphone not working

Started 3 days ago. I’ve had this iPhone 7+ for over a year, and never had issues with the microphone. I can’t hear or speak to anyone on a phone call (even though the call appears to go through). I can’t talk to Siri or even use my “Shazam” app to listen to a song I might want to purchase.

Ive alread tried several soft resets, and 3 hard resets. I also completed the last software download and upgrade. I know the external speakers work; because I can hear music out of them. However, I cannot use a wired headphone set.

Currently I have an appointment at the Apple Store to have the phone looked at this coming Thursday afternoon.