ok I have installed Skype and did the test with echo/sound test service and as you say it doesn't work
I'm trying to understand what is the problem
edit:
in logcat I see:
codice:08-15 17:15:43.021 403 23332 E audio_route: unable to find path 'low-latency-record' 08-15 17:15:43.021 403 23332 D audio_hw_primary: select_devices: done 08-15 17:15:43.029 403 23332 E audio_hw_primary: start_input_stream: cannot open device '/dev/snd/pcmC0D15c': Invalid argument 08-15 17:15:43.029 403 23332 E audio_route: unable to find path 'low-latency-record' 08-15 17:15:43.029 403 23332 D hardware_info: hw_info_append_hw_type : device_name = handset-mic 08-15 17:15:43.032 403 23332 D audio_hw_primary: start_input_stream: exit: status(-5) 08-15 17:15:43.032 403 23332 D audio_hw_primary: in_standby: enter: stream (0xb5f16b80) usecase(11: low-latency-record)