Question CM 10.1 Bluetooth/Sygic Mobile problem


I use CM 10.1 Stable on my N7100.Everything is okay about the phone, except one situation.I want to listen and follow Sygic Mobile's guidance
voices by my bluetooth earphone, when i use it.But the problem is i can not use it.The app uses Phone speaker for the voices, but when i make a call by the bluetooth, i can hear both call and sygic's voices.But when i turned off the call, it goes again.And phone starts to use its speaker again.Is there a way to fix this problem?Thank you.