For the weird interference noise, please try for a few minutes to keep mobile phones away / turn them off – this would rule in / out any other device nearby.
You can tell as the 3G is disappearing from the phone display.
If phones are switching from 3G to 2G networks there is a chatter that is pickup up by headphone amplifiers.
It may be the xCan has an issue or it may be the network switching.
Newer 4G networks don’t have this interference – it is a legacy thing.
