Listen my microphone during a call topic

First, sorry for my bad English.


Everytime i can hear my voice, during calls, in loudspeaker and that returns to microphone causing echos and strong noises....How i can turn off that? There is no fix for that? Like a flashable or some workaround?


Please help me i'm unhappy for that, this phone is new and i like xperia's series but this is very annoying