Problems with call quality.

[WalterG]

I have my Xperia T now for almost a year, and recently when I call someone they claim that they can’t hear me. If I scream at the phone they can hear me better. Is there a problem with the phone microphone or what can I do. 

I have had this problem in several cities and places, house, car, and outside.  So I do not think that it is signal related

[Alexander1]

You can test the microphone in the Xperia diagnostics app: 

https://play.google.com/store/apps/details?id=com.sonymobile.androidapp.functiontester

You can also start your phone in safe mode to see if the problem may be related to any 3rd party app installed in your phone:

http://talk.sonymobile.com/t5/FAQ/How-to-boot-your-phone-into-safe-mode/m-p/348008#U348008