I can call and answer calls talking normally and it's all fine. I tried once switching to loudspeaker and the other person could not hear me. Probably it's the same as when I run sound recording. The volume meter shows about 30% in silence and resulting record is just nothing but loud noise. Even if I talk during recording it is hardly or not hearable. Sensors application shows value of roughly 64dB until I knock the microphone or blow at its hole. Then the volume falls to about 43 - 47 dB and when I say something it makes diffenece on the plot. Similarly, when recording sound, knocking or blowing into the microphone lowers volume meter, the noise on record disappears and the real sound is being recorded. This isn't hardware issue because this happens each time I start recording again and doesn't come back until I stop.

I suppose some option under the code *#9646633# may help but this menu is so "engineering" that I don't know where to go and what all these values do mean.

Dear @admin, could you explain their meaning to let me adjust them and have clear recordings since beginning and be able to make calls in loud mode?

Sounds like it's maybe the same issue like here: viewtopic.php?f=142&t=163750

It's possible although I want to get rid of noise that is caused probably by too high sensitivity while the other user wants to be heard by increase sensitivity. The difference is that he has trouble while talking in phone mode and I have problem with recording. These are two modes, configured probably by different values. Could you please provide instruction which option select in menu and which values may be helpful? We may be trying for days and still don't find the solution because there are many values which meaning we don't know. Some might be gain, some might mean frequency, some may be threshold. It could be handy if we knew what do we really configure. Mastering it, we'd be able to help other users as well.