英语考试完型填空练习题

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 if 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 where 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. Its a burst of white noise __7___ people say sounds like static on the radio,she says. Its life-saving potential is great.

She conducted an experiment in which people were filmed by thermalimaging cameras trying to find their way out of a large __8___ room. It __9___ them nearly four 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____ 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.