The speakers own magnetic field from the magnet should not effect the internal wire unless that wire is moving. you need a wire moving in a magnetic field to induce a current/voltage with out a moving magnetic field or moving wire in a magnetic field you get nothing. so if for example the wire was pulsing with the air movement then yes you could get induction. I think you would get more from external sources like all the emi from the world like radio/ radar/ac line voltage in your homes ac system and the power co transmission lines. I've worked with systems in the Navy that detect various RF/EMI and you'd be shocked at how much we are be bombarded with daily. you just can not get away from it regardless where you are on the planet, less of course in remote areas but never zero (sun bathes us in a lot for that mater)
