Call quality

[byrds8]

When talking on the phone it often sounds like the other person, IE my wife, is on speaker phone when she isnt. We both have TB and its a bit too high pitched. Is there anything I can do to solve this or is that just the way it is. Although its hasn't been like that for everyone Ive spoken with. I hate having to ask her to repeat what she says. It surely isnt because it is not loud enough though lol