I use a Lumia 730
When I receive a call, I can hear the caller, but the caller cant hear me.
When I speak into the microphone, I hear myself after about 1-sec delay sounding far away (like a fading echo).
I have exactly the same problem, phone worked fine this morning, ran the denim update and now when make a call or take a call no-one can hear me, I can hear my own voice coming back. If I hit the speaker phone button they can hear me fine. Cortana doesn't hear me anymore either. Am on a Lumia 930. Since this morning I have done the following.
Roll back to previous code using the MS tool
Hard reset in old code
Update to denim again
Hard reset again
I tested at each stage and the issue is exactly the same.
I bought the handset off contract and the Warranty app is telling me I'm out of warranty so effectively the Denim update has ruined a ?400 phone. Am having to use an old 920 now. Has anyone got anywhere with resolving this?
Re: why is microphone not working since demin update on Nokia Lumia Icon
Nokia 928 with non-working secondary microphones. Still testing, but I suspect a software issue, not hardware.
The mics quit working shortly after upgrading to WP 8.1 DP. Prior to that, mics worked fine. Afterward: Cortana could not hear anything, speech to text could not hear anything, MS and Lumia Camera audio record only static.
On a whim, turned Cortana off, rebooted phone (as requested), and secondary mics work again.
However, first time use MS Camera to record video, only static. And mics stop working again.
Reboot seems to fix. Lumia Camera seems not to kill mics.