|
Singing Alarms Could Save the Blind If you cannot see， you may not be able to find your way out of a burning building-and that could be fatal. A company in Leeds could change all that__1__ directional sound alarms capable of guiding you to the exit. Sound Alert， a company__2__ the University of Leeds， is installing the alarms in a residential home for__3__ people in Sommerset and a resource centre for the blind in Cumbria.__4__produce a wide range of frequencies that enable the brain to determine the __5__ is coming from. Deborah Withington of Sound Alert says that the alarms use most of the frequencies that can be __6__ by humans. It is a burst of white noise__7__ people say sounds like static on the radio， he says. Its life-saving potential is great She conducted an experiment in which people were filmed by thermal-imaging cameras trying to find their way out of a large__8__ room. It__9__ them nearly our minutes to find the door__10__ a sound alarm， but only 15 seconds with one. Withington studies how the brain__11__ sounds at the university. She says that the __12__ of a wide band of frequencies can be pinpointed more easily than the source of a narrow band. Alarms__13__ on the same concept have already been installed on emergency vehicles. The alarms will also include rising or falling frequencies to indicate whether people should go up__14__ down stairs. They were__15__ with the aid of a large grant from British Nuclear Fuels. | 
