if im not wrong the interference affects the sending/receiving equipment not the actual signal itself, the reason those cheapo pc speakers picked up the tell tale pips of an incoming mobile call is because they likely werent shielded (back in the days of cathode ray tvs/monitors this could be an issue as putting unshielded speakers too close to the tv caused issues)

but mission critical equipment like life support systems, airplanes and other such tech would never be allowed to be produced and used without at least basic shielding all round