Utilising induction loops for applications such as museum exhibits where attendees tend to be moving through a space in a short period of time and therefore cannot easily access loan equipment, is a common practice. Since the majority of new hearing aids have T-coils installed, users equipped with these do not need to request extra equipment to receive the signal. The only requirement being to simply move a switch from M to T (mic to T-Coil) on the hearing aid.
In a museum, where the user will be moving across a number of exhibits, assistive listening solutions using RF/FM which by its nature is a broadcast medium require users ask for equipment and be directed to change frequencies to pick up a specific audio feeds or areas.
Hearing loops can be designed to confine their coverage to tightly defined local areas for the benefit of both the hearing impaired and non-hearing impaired, by delivering audio for an exhibit to the viewer/attendee by having them simply move into that loop area.
The normally abled user would be provided with a loop-listener which works on the same principal as the T-Coil in the hearing aid. For this type of application a low overspill area coverage system would be designed. This noticeably improves the user experience and eliminates the possibility of user error.
Another significant benefit with these types of induction loop systems is the ability for addition of further looped areas at a later date. Low overspill induction loop systems provide an opportunity for further expansion without tearing out existing systems with the related cost and disruption. For example; when an exhibit is added locally within the museum, the field from the existing loop(s) is already localised to the specific area of the current exhibit(s) and therefore no issue with cross talk or addition of more RF channels has to be addressed.
In order for a system like this to work satisfactorily the electromagnetic noise floor must be clear of background noise produced by units such as transformers. Occasionally people complain that induction loops are noisy when you step outside the looped area. This is not noise produced by the loop but rather, electromagnetic background noise produced by noisy transformers or bad wiring practice within the building, such as live and neutral power being separated by a long distance and forming a loop, causing the signal to noise ratio to be much higher than is acceptable. In most situations where a buildings electrical wiring is modern and the loop is positioned away from any noisy transformers this noise outside a low overspill loop is too low to notice.
The following is an example of a museum system that utilises a combination of localised systems and low overspill induction loops to provide a free moving guided tour to its patrons allowing them to move seamlessly between exhibits without having to conform to a pre meditated tour or change between channels when moving between exhibits. As you can see a large number of areas are covered simultaneously.