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 ____________ (51) all that with directional (定向的) sound alarms capable of guiding you to the exit. Sound Alert, a company run __________ (52) the University of Leeds, is installing the alarms in a residential home for ______________ (53) people in Sommerset and a resource center for the blind in Cambria. The alarms produce a _____ (54) range of frequencies that enable the brain to ________ (55) where the sound is coming from. Deborah Withington of Sound Alert says that the alarms use most of the frequencies that can be __________ (56) by humans. “It is a burst of white noise that people say sounds like static (静电噪音) on the radio,” she says. “Its life-saving potential is ______ (57).” She conducted an experiment in which people were filmed by thermal-imaging (热效应成像)cameras trying to find their _________ (58) out of a large smoke-filled room. It ________ (59) them nearly four minutes to find the door without a sound alarm, ________ (60) only 15 seconds with one. Withington studies how the brain ______ (61) sounds at the university. She says that the _________ (62) of a wide band of frequencies can be pinpointed (精确地确定) more easily than the source of a narrow band. Alarms ___________ (63) on the same concept have already been installed on emergency vehicles. The alarms will also include rising or falling frequencies to _________ (64) whether people should go up or down stairs. They were ______________ (65) with the aid of a large grant from British Nuclear Fuels.

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