Xperia C4 Duos Call not hear the other side

[PepsaN]

Xperia C4 Duos Call not hear the other side.

Call me hear very little from the other side

[Phy]

Does it work on safe mode?

How to boot on safe mode
http://talk.sonymobile.com/t5/FAQ/How-to-boot-your-phone-into-safe-mode/m-p/348008#U348008

How to boot on safe mode on Lolipop
1. press and hold the power key
2. once you get the pop up menu 
3. press and hold "power off" 
4. Boot on safe mode should become available

[Jake-SonyXperia]

Hi PepsaN,

Welcome to the community,

Are you getting the same issue with a headset? Also are you using any covers on the device?

[heap11]

When I had a similar problem it was caused by congestion on the network, not the phone. T-Mobile tech support was able to fix it by resetting the signal to my phone from the cell tower.

[PepsaN]

Hello everyone, I have tried to speak with headphones and hear me well. Phone there is no additional covers. Nor is the problem in the network operator because there is another device on the same operator and there is no problem.
When I talk to Xperia C4 Duo people say that many hollow or poorly hear me.
  Whether the problem is not only the microphone when calling Cause tested it with diagnosis and hear well.

[PepsaN]

Do I ask  Xperia C4 Duo model has two microphone why a conversation is activated rear microphone rather than lower. When I speak of the microphone which is on the rear panel to the camera people hear me very well how can I set the phone to hear only through the bottom microphone which should be calling?

[MSoliman]

I have the same problem with C4. Seems like a faulty or bad quality bottom mic? If the conversation is activating the rear rather than the bottom, so this is a software issue (I guess). But here is what I noticed: When I put my mouth near the mic at the back people will hear me clearly, but when I talk normally while my mouth is near the bottom mic people won't hear me clearly. It is not a network problem, a sim problem, or a software problem. I tested all related solutions, updated my software, resetted the phone many times, booted in safe mode, and still no hope!

According to my understand, the back mic is for noise suppression, so both mics work together at the same time.