i hear radio waves looping the same thing in my home!

we recently bought three iphones and on a family plan, me my husband and mother in law who lives 13 blocks away. for some unknown reason when my husband goes to her house and talks to her(phones are off) then comes home i hear everything they talked about through metal or something in my home! then it just loops over and over! i tell them everything i hear and they are stumped! its driving me crazy hearing it over and over! what is this? what causes this? and how do i turn it off ? we live right under a radio tower and i have never experianced this before we got these phone! they only hear a muffeld sound but i hear it clearly as if they were sitting across from me talking! its strange and annoying! any help please!?