[OpenSIPStack] changing level of microphone during talk

[tomach <to...@dg...>]

Hello!

I try to describe my probelm:
1. I make connection on codec 711.
2. During talk I changed level of microphone several times or even mute it totally.
3. Then I notice that quality of voice is worse then before point 2.

Is it normal? Do You have the same problem? Or is it technical imposible?