I just posted this over in the Motorola Owner's Forums under a discussion regarding the same issue:
Matt arranged a conference call today with some Moto engineers, me and another Moto X user. We did a lot of testing and the engineer that conducted the call was able to reproduce the...
There is a known bug in Assist that causes this behavior. To disable it completely go into Assist, Settings and then uncheck the Driving check box. If you only uncheck the Talk to Me option on the main screen, but do not uncheck the Driving option under Settings, the problem will continue to...
I swapped out my Moto X for a new one late yesterday and this one doesn't seem to be any better. In fact, it may be a tad worse when it comes to over all voice quality.
Based on some of the other discussions here at the the Motorola Forums, there are quite a few others having the same issue, including me. It seems to happen only with the handset mic. Speakerphone and bluetooth don't seem to have the same issue.
Having the same issues here with my Verizon Moto X. At least three or four times a day I have people on the other end tell me I'm not coming in clear, words are getting cut off, I sound too quiet, whatever. My brother also has a Moto X and when I called him yesterday I was noticing the same...