Ok, Steve, thank you. I thought I was using the wrong configuration to use md380-emu.
Although in the log you can not see that md380 will be used. There is information that
I: 2019-09-07 06:54:58.179 Connecting to emulator on host 127.0.0.1:2500
W: 2019-09-07 06:54:58.179 Using software MBE decoder version 1.2.3
W: 2019-09-07 06:54:58.179 Using software OP25 IMBE/AMBE vocoder
Still, sometimes strange audio using md380 (Jackhammer) occurs. It changes the port of md380-emu and sometimes helps, but I think this is not the reason for strange audio.