iPhone 7, iOS 12.4 > Caller cannot hear me, speaker button unavailable, dictation inoperable

I have an iPhone 7 running iOS 12.4. Prior to updating my software today, when I made a call, the caller could not hear me unless I had them on speaker. The speaker button was sometimes unavailable.

In hope of fixing this,

-I rebooted twice.

-I upgraded my software.

-I've cleaned my receiver,

-removed my headphones,

-unplugged from my charger

-removed my phone case.

Nothing has been fixed as a result of any of these attempts at repairs.

• The speaker button is now unavailable when I call or am called.
• I've also noticed that dictation (talk to text) is now inoperable.