[Sound clip] That's the future sound ___1___ city streets. If President Obama has his way there will be one million electric vehicles on the road by 2015. This week the National Highway Traffic Safety Administration started a process to determine what should be done to make it easier for pedestrians and others who share the road to ___2___.

[clip 1] That electronic [sound clip] is one of several alternatives if the NHTSA decides to require these cars to add sounds. Here's another [sound clip].

The goal is to give an audio cue, not unlike the beeping associated with the ___3___ of large trucks. Why? Well, a study led by psychologist Lawrence Rosenblum of the University of California, Riverside found that ___4___ test subjects could hear an internal combustion engine 36 feet away but didn't hear a hybrid until it was a mere 11 feet away.

That left ___5___ few seconds to react before the hybrid reached them. And that's not safe. Which is why the electric or hybrid cars of the future may sound so, well, futuristic.
【视听版科学小组荣誉出品】
filling detect these quiet cars backing up blindfolded scant
听见了么，这可是马路未来之音。假如小奥的计划得以实现的话，那到2015年将有一百万辆电动汽车投入使用。本周美国国家公路交通安全管理局着手计划如何方便行人及其他车辆发觉这些静音车辆。 假如NHTSA决定为电动汽车添加声音设备的话，这种电子设备将是备用选择之一；这是另外一种声音。 这么做是为了提供一种声音提示，和大卡车倒车时的提示音没什么不同。为什么呢？加州大学河滨分校的心理学家劳伦斯布鲁姆主导的一项研究表明戴眼罩的测试者在普通汽车与他们相距36英尺时就能听到其内燃机的声音；而混合动力车的声音要到相距11英尺时才能听见。 于是混合动力车冲过来之前，反应的时间是少之又少，不安全是肯定的。所以，电动汽车或混合动力车的未来是多么的虚无缥缈。