during calls, mic doesn't work, unless speakers are on

[Pathos]

When I receive calls or when I call somebody, the mic doesn't work at all, unless if I turn speakers on..
Sometimes, generally after an OS update, the bug disappear, but a few weeks later, the bug is back again.
It's a bug from the Phone App, since the mic works always perfectly with a Voice Memos app.

Phone : bq Aquaris E4.5
OS : Ubuntu 15.04 (OTA-14)
Description : armhf (20161118-171123)
Last update : 13/12/2016

Thank you (and sorry for bad English).

[Pathos (pathos)]

Changed Dropping Letters to phone-app