Have you ever wondered why overhearing a cellphone conversation is so annoying? American researchers think they have found the answer。

　　Scientists at Cornell University say that - whether in the office, on a train or in a car - only half of the conversation is overheard, and this drains more attention and concentration than when overhearing two people talking。

　　"We have less control to move away our attention from half a conversation (or halfalogue) than when listening to a dialogue," said Lauren Emberson, a co-author of the study that will be published in the journal Psychological Science. "Since halfalogues really are more distracting and you can't tune them out, this could explain why people are irritated."

　　Emberson also said that in such a situation people try to make sense of snippets of conversation and predict what speakers will say next. "When you hear half of a conversation, you get less information and you can't predict as well," she said. "It requires more attention."

　　The findings by Emberson and her co-author Michael Goldstein are based on research involving 41 college students who did concentration exercises, like tracking moving dots, while hearing one or both parties during a cellphone conversation. The students made more errors when they heard one speaker's side of the conversation than when they overheard the entire dialogue。

　　无意间听到别人通过手机聊天，自己却开始心烦意乱，你有没有思考过这是为什么呢？近日美国科学家们找到了答案。

　　来自路透社的报道称，康奈尔大学的科学家宣称，不论是在办公室、火车上还是小轿车上，人们听到一方的电话交谈时，需要投入的注意力以及精力要高于听到双方完整谈话所需。

　　“与听到两人交谈相比，只听到一人说话更让我们容易分神，”这篇登上《心理科学》的研究论文的撰写者之一劳伦-艾伯森说道。“因为一人说话更让人分心，而人们不可能对此无动于衷，这可能就是人们心烦意乱的原因。”

　　艾伯森还称，在这种情况下，人们会试图搞明白只言片语背后的完整含义，并预测说话者接下来要说什么。“当你听到一半对话，信息不充分，让人无法预测，”她说。“这就需要你投入更多的注意力。”

　　这项研究结果是艾伯森和米歇尔-戈德斯坦在调查了41位大学生后得出的。大学生们被要求做注意力集中测试，比如边听一方(或者是两方)打电话边追踪移动点，结果发现，只听到一方谈话内容的学生要比听到完整对话的学生的出错率高。