Well in our old aeroplane with the original non FM immune radios, we always were reminded to turn off our mobile phones because of the "dit dit dit" in our ears as the phone was logging in.
In our new shiney plane with a Garmin G1000 there is no interference from mobile phones. Presumably this is because the radios etc have undergone a lot of EMC improvement.
I suspect that the new avionics wouldn't be bothered by these HIRTA transmissions.
Any thoughts?