Q: Speaker phone function randomly drops out during call

Thanks, but that's not the issue.

The speaker works just fine.  The sound is not distorted.  Rebooting does not help.

This is an issue of the "speaker" button turning white when depressed, hearing sound from the "speaker", and then without touching the controls in any way, the "speaker" button goes black and no sound is emitted from the "speaker" until I depressed the "speaker" button again - 4 times.

Have not approached carrier regarding this problem.  Not quite sure how it could be carrier related.  The call is never terminated, nor is call quality affected in any way.  The entire problem seems to reside within the phone. 

Perhaps the only other thing that is noteworthy is I have a LifeProof case on the phone.  I had another case (non-Apple certified) and the problem exists with either case installed.