Turns out the problem was with my SIM-Card, the problem occurs in other phones to.
** Changed in: dialer-app (Ubuntu) Status: Confirmed => Fix Released -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to dialer-app in Ubuntu. https://bugs.launchpad.net/bugs/1527303 Title: Audio echo instead of call Status in dialer-app package in Ubuntu: Fix Released Bug description: When calling, or being called, there is a chance of about 20% that, when the call is accepted, the only thing you hear is your voice as an echo. The other person ( I tested it multiple times, with different setups, e.g. Ubuntu phone to Ubuntu Phone, Android to Ubuntu Phone, etc. ) can hear me, but I only hear my own voice. This bug also affects two other Ubuntu Phone users that I know, and it really is annoying. If you need further Information (crashdumps, logs etc) I'm happy to help. The bug is not fixed in OTA 8,5. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/dialer-app/+bug/1527303/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp