Hi @Willsta, sorry to hear about this.
The main microphone of the XZ1 is located at the bottom of the frame (see point 12 in this overview), please ensure that this microphone is not covered by any protective case or any lint or dirt from for example a pocket. Also, try testing the hardware using the support app, find and tap Settings > Support > Xperia Tests > Speakers & microphone.
Another thing that you can try is to reboot your phone in safe mode to see if the main microphone works better there. Safe mode is a troubleshooting mode where all apps downloaded from Play Store is temporarily deactivated, that way you can see if this behaviour is caused by a downloaded app. For more information on safe mode and how to use it, click here.
If the behaviour of the microphone persists in safe mode, 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 how it goes!
