typedef enum {
  VM_AUDIO_DEVICE_SPEAKER = 0,
  VM_AUDIO_DEVICE_MICROPHONE = 1,
  VM_AUDIO_DEVICE_SPEAKER2 = 4,
  VM_AUDIO_DEVICE_LOUDSPEAKER = 5,
  VM_AUDIO_DEVICE_SPEAKER_BOTH = 6,
  VM_AUDIO_DEVICE_BT_HEADSET = 8
} VM_AUDIO_DEVICE;