Android L - people can't hear me.

[Geliosoft]

The person I am calling on my Z1 Compact (Android L) cannot sometimes hear me. Are there any suggestions to resolve this problem?

 

[Geliosoft]

Is there any way to fix this or I need to update Android?

 

[Geliosoft]

Is there anyone who can help me?

 

[Geliosoft]

Got the solution, guys.
Go to google-settings (not the phone settings!), google search and disable the "Ok Google"- hotword detection on every screen. It helped me instantly! Thank you all very much.