[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.
【視聽版科學小組榮譽出品】
filling detect these quiet cars backing up blindfolded scant
聽見了么，這可是馬路未來之音。假如小奧的計劃得以實現(xiàn)的話，那到2015年將有一百萬輛電動汽車投入使用。本周美國國家公路交通安全管理局著手計劃如何方便行人及其他車輛發(fā)覺這些靜音車輛。 假如NHTSA決定為電動汽車添加聲音設備的話，這種電子設備將是備用選擇之一；這是另外一種聲音。 這么做是為了提供一種聲音提示，和大卡車倒車時的提示音沒什么不同。為什么呢？加州大學河濱分校的心理學家勞倫斯布魯姆主導的一項研究表明戴眼罩的測試者在普通汽車與他們相距36英尺時就能聽到其內(nèi)燃機的聲音；而混合動力車的聲音要到相距11英尺時才能聽見。 于是混合動力車沖過來之前，反應的時間是少之又少，不安全是肯定的。所以，電動汽車或混合動力車的未來是多么的虛無縹緲。