According to an example embodiment of the present invention, there is provided an apparatus comprising at least one receiver configured to receive signals relating to a position of a device relative to a head, at least one processing core configured to determine, at least in part based on the received signals, the position of the device relative to the head, to compare the position of the device relative to the head to information concerning a position corresponding to a maximal induced electric field, and to cause signals to be transmitted, and wherein the transmitted signals are configured to cause a display to indicate a deviation of the position of the device from the position corresponding to the maximal induced electric field.