Phone call: Audio works only with speakerphone or wired headset The following issue with my Sony Xperia ZR (running CM 11-20141112-SNAPSHOT) started a few days ago:


When I initiate or receive an ordinary phone call, I can't hear the other side through my earpiece and the other side can't hear me either.
When I plug in the wired headset, I can use that without problems.
When I activate the speakerphone button during the call (without the headset plugged in), I can communicate with the other side.
I also have a "click" sound effect for locking and unlocking the phone and this sound effect is now also only audible through the headset.


Here is what I tried:


First of course, I checked my profile and volume settings to make sure they are on Default and the in-call volume turned up.
I re-started my phone multiple times, sometimes with, sometimes without the headset being plugged in.
I thought that the headphone jack might be broken, i.e. that it thinks the headset is always plugged in - especially since I use the headset a lot for listening to audio while walking. But as soon as I plug in the headset, the Apollo audio player app starts, suggesting that the headphone detection works fine. Unfortunately, I haven't found a way to see if the software thinks that the headset is connected or not - is there a headset icon or similar I could enable?
So I thought it might be a software issue. 


I installed the Sound Manager app which allows to adjust all volume settings and 
found that it behaved a bit strange when I touched the In-Call Volume slider, causing a sound blip coming out of my earpiece. Also the volume "overlay" (or whatever you call that window that pops up when pressing the volume rocker) became visible, but sometimes only its icon, not the slider itself. 
After adjusting the volumes through that app, I could make a test call without headset and without the speakerphone enabled which worked fine. Also the phone (un-)locking sounds were working again. 
However a couple of hours later, when I unlocked my phone again, I didn't hear the click and doing a test call I realised that the problem had re-appeared.
So I went back to the Sound Manager and adjusted the sliders once more, this time no strange effects as in 4.2 before. And no click when locking/unlocking and no audio through the earpiece &amp; mic during my next test call.



Short of completely re-setting my phone (which I'd like to avoid), is there another way of debugging this issue? Does CM have a way to tell the headset detection status?

Any other things I could try?
Similar issue in OnePlus One (running CM 12.1). Check TTY Mode. If its off turn it back on and restart phone. Go back to TTY mode again and turn off and restart. It worked for me on OnePlus.