Share your experience!
Guys, since yesterday it seems, that I have issue with my microphone when I am using the phone app.I read many threads in this forum and applied proposals but nothing helped. Safe mode, another SIM card, Restate telefone. When I use loud speaker, then the other call participant can hear me, but as soon I move to normal mode, they can't hear me anymore.
Video reording, call over Viber, Call via headset, loudspeaker all fine.
The level of the hardware tests is quite low, so I expect hardware issue.
Is there anything else, befor I go to the hardware guys?
Adroid version is Oreo 8.0.0
Hi @Chilo, I am sorry to hear about this.
the XA1 Ultra-model has a total of two microphones. A main microphone located at the bottom of the display used in calls and a secondary microphone used for other recordings such as video and calls on loudspeaker. To see where these microphones are located, please see item 4 and item 11 the overview of XA1 Ultra.
First of all I would suggest that you check if there is water, dust or any kind of protection such as a protective case or a protective film blocking the microphone or the area around the microphone.
I would also suggest that you use the Tests feature in the Support app to carry out a quick test to check that the loudspeaker is working properly. In order to do this, fins and tap Settings > Support > Xperia tests > Media.
Another thing that you can try is to reboot your phone in Safe mode. All apps downloaded from Play store is deactivated in safe mode and by doing this you can see if there is a downloaded app that is causing this. For more information and instructions on how to enter safe mode, please click here.
If none of these measures work to improve the sound from the microphone I would suggest that you try to perform a software repair using a computer and Xperia Companion. Please note though that a software repair will erase all user data, so remember to do a backup of your user data first.
Try these measures and let me know how it goes! 
Thanks, it looks like a hardware issue...
Thank you @Chilo for your quick reply!
In that case I suggest that you get in contact with your local support team. They can help you to have your phone sent to an authorized service center to be examined and repaired. If you have any questions regarding the service, such as routines, warranty and consumer laws, these type of questions are best answered by your local support team as well, as they vary between markets.
Feel free to return if you have further questions!