iPhone 6+ "Sounds like you're in a tunnel"

[jussumdude]

Ever since getting my Verizon iPhone 6 Plus, people I'm talking to say I sound like I'm in a tunnel, or they don't hear me at all. I can sound great one moment, and gone the next... only to come back again on the same call. It is happening on 80% of my calls. Apple has replaced the phone twice so I don't think it's hardware, but Verizon seems stumped. They are now sending me yet another new 6+, but I know this isn't going to help. Anyone else having this issue?

 

[Tytanious]

I had a similar problem. Replaced the phone twice and no one knew the issue.

For me the final culprit was having LTE enabled for voice & data. Which is lame because Verizon finally enables it for the iPhone but I can't use it without making my phone calls unusable.