Q: Аt times they do not hear ме well at call ?

Hello Bogoev,

Thanks for using the Apple Support Communities!

I understand that sometimes when you are on a call, the other party has a hard time hearing you. I know how frustrating these type of microphone situations can be, but we do have a great article with some very good troubleshooting included for issues such as these. 

Please read over and work through the steps located in the following article to begin troubleshooting the microphone on your iPhone. 

Get help with the microphones on your iPhone, iPad, and iPod touch - Apple Support

Cheers!