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 with directional sound alarms capable of guiding you to the exit.
Sound Alert, a company run by the University of Leeds, is installing the alarms in a residential home for blind people in Sommerset and a resource centre for the blind in Cumbria. The alarms produce a wide range of frequencies that enable the brain to determine where the sound is coming from.
Deborah Withington of Sound Alert says that the alarms use most of the frequencies that can be heard by humans. "It is burst of white noise that 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 thermal-imaging cameras trying to find their way out of a large smoke-filled room. It took them nearly four minutes to find the door without a sound alarm, but only 15 seconds with one.
Withington studies how the brain processes sounds at the university. She says that the source of a wide band of frequencies can be pinpointed more easily than the source of a narrow band. Alarms based 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 or down stairs. They were developed with the aid of a large grant from British Nuclear Fuels. [理工类C]
警报器救盲人
如果看不见，那你可能会因找不到路而逃不出一幢失火楼房，那将是致命的。英国利兹市的一家公司发明的一种可指方向的警报器可能会把你引向出口。
声音警报是一家由利兹大学设立的公司。该公司现在正在为位于萨莫塞特的一家盲人收容所和位于卡姆布雷亚的一家盲人资源中心安装此种装置。这种警报器发出的频率范围广，使人脑可以判断出声音的来源。
该公司的戴博拉·威星顿称此种警报器使用人类可以听到的大部分音频。她说：“它们是一种突出的频谱连续而均匀的噪音。人们感觉它们听上去就像是收音机发出的静电噪声，其在救人方面潜力巨大。”
她进行了一次试验。她让人们在一所充满浓烟的大屋子里设法找到出路，同时她用热效应成像摄像机进行拍摄。在没有警报器时，这些人用了近4分钟才找到门，而在警报器的指引下，只用了15秒。
她在大学里对人脑如何处理声音进行研究，并提出与波段窄的频率相比，人们更容易发现波段宽的音响源。基于此理论的警报器已被应用于急救车上。
这种警报器也容纳了音频的升降，以指示人们上、下楼。这种设备是得到英国核燃料组织的大笔资助才开发成功的。[理工类C]