Is the whining you mention in your description not the flaps extending?
With regards to the electronics turned on the program mythbusters looked into this using a single engined cockpit mounted on the back of a truck and a mobile phone, the signal did cause interference with avionics but then when tried on a modern jet it didn't, obviously this was only tested on the ground and not during flight.
There are plenty of videos from within the cockpit with multi cameras that must have had the airlines permission to be on so if it's safe up front why wouldn't it be less safe in the back (just saying).