Peter N

They use induction loops in a number of Government buildings that I have worked in and they can and do leak. The following is from the RNID (Royal National Institute for the Deaf) website...

Be aware that the loop signal can spill out beyond the area within the loop to other rooms. Walls, ceilings and floors do not block the magnetic waves from a loop. So you may be able to overhear sounds or conversations in rooms next door or directly above and below the loop. This could be a problem if your neighbour also uses a loop system, or if you want to have a confidential conversation.