Since coming back from a local flight and doing some further testing, I notice you get some background noise when using the sound card on the PilotAware. But if I plug my mobile into my headset there is no background noise, so is the sound card on the PilotAware always on, even when no alerts are being transmitted, if this is the case this maybe my issue with some interference within flight.
The volume is nice and clear when the alerts are being transmitted, it's this annoying interference which is causing a problem.
Is anyone else able to test there PilotAware on the ground and see if you get this background noise, then if you test your mobile there should be no noise.