i had that happen on my nexus 5. for me, it was a bug in the headphone jack, though i didnt bother to go about fixing it. in a call, the phone thinks theres an

i had that happen on my nexus 5. for me, it was a bug in the headphone jack, though i didnt bother to go about fixing it. in a call, the phone thinks theres another mic installed, and tried to use that instead.