Why is phone voice quality so poor in Marshmallow Nexus 6?

[AC Question]

Last summer, when new, my Nexus 6 with Lollipop had wonderful phone call quality. Not now with Marshmallow.

Is there some kind of app that would smooth out the ragged speech?

 

[B. Diddy]

Welcome to Android Central! Is the call quality also bad when using a wired or Bluetooth headset? Are you sure it isn't a problem with the network? Check with your carrier. Make sure any option for HD Calling/Advanced Calling/VoLTE is turned on, if at all possible. If the phone is capable of wi-fi calling, try toggling that on or off, depending on what it's set to right now.

 

[Tom Egan]

Thanks for your ideas. I just don't know enough about the technology. I'm going to have to throw myself on the mercy of Help at Google Project Fi which I'm using. It's a beta test, so maybe I'm caught up in some geeky problem that I don't have a chance of solving. (My old flip phone didn't have this problem from this location.)

 

[Tom Egan]

Turned out to be a fairly simple fix. The Project Fi Help person walked me through the process of clearing data and cache in the Project Fi app. I don't know what that did to the system, but all the dropouts are gone now.