听力是听和理解能力的总和。语言知识是听力理解的必备条件。没有一定的语言知识基础，要听懂是困难的。语言知识包括语音、词汇和语法。学生自己发音不标准，就会造成近音词之间的混淆。学生辩音能力不强就不能正确辨别语流中的语音变化。如同化、强弱读、连读、失去爆破等。语音基础的优劣直接影响听力水平的高低。因此起始阶段训练学生音素和单词时，1）要注意听辨发音相似的易混淆的因素、字母、单词、数词等。例如：[Ι][ⅰ:],[∧][α:],[е][ ],[s][z],[n][l]等音素。bit/beat, cut/cart, bed/bad, light/night, cause/course 等词以及数词18/80 ， 8:30 / 8:13 ， 1990/1919 等的读音区别。2）掌握音素和单词在语流中的变化。常见的变化有四种：①音的省略，指元音音素[Ι]或[ ]在非重读音和重读中的省略。②音的连读，指在短语或句子中相邻的两个词，当前一个词是辅音结尾，后一个词是元音开始时，需要连读。③音的不完全爆破，指爆破音[p],[b],[t],[d],[k],[g]后跟破擦音、摩擦音、鼻音或舌侧音时，或者两个爆破音相邻时，前面的爆破音不完全爆破，而在口腔中形成阻碍，既停顿一下发出下一个音。④音的同化，指相邻的两个音受另一个音的影响而发出第三个音。因此，学好音标，过好音标关，从一开始打好语音基础、掌握朗读技巧，对提高听力理解能力无疑会起到事半功倍的效果。
參考答案:Listening is the summation of audition and comprehension. Linguistry is the necessary condition of listening. We can understand this, provided having adequate basis. Linguistry includes sound, vocabulary and grammar. The students will be confused of the similar words if they do not pronounce the words exactly. Without good ability of distinguishing the tone, they can not discern the change of speech, such as assimilation, strengeth, continuance,失去爆破 and so on. The students' level of listening depends on the linguistry basis. Here are the emphasis on training the students in phonome and vocabulary below:
1.listen carefully to the phonome, letters, words and numeral which are easy to be promiscuous. For example: ：the phonome like [Ι][ⅰ:],[∧][α:],[е][ ],[s][z] and [n][l]; the words as bit and beat, cut and cart, bed and bad, light and night, cause and course; the pronunciation difference between 18 and 80, 8:30 and 8:13, 1990 and 1919.
2.Being in control of the change of the phonome and words in the speech. There are four usual changes: 1.2.3.4(这里查字典太麻烦了）
因此，学好音标。。。So it will indubitably get twice the result with half the effort in improving the listening if the students can learn phonetic symbol and hold the reading tip well.
What is the most important factor which affects the students' listening? As the survey result, vocabulary is the first one. This illustrates that during the listening process, the students quite depend on their vocabulary. So, it is crucial to build a great vocabulary.
At the same time, the students not only have to differentiate the voice, but also digest the meaning of the new words, otherwise, it is hard to understand. Grammar, which is the same as vocabulary， can help us as a necessary condition and basis understand and estimate the details of the action. How good at grammar the students are directly affect the result of listening.
