作者：王玉君
　　Quality input ensures quality output. Input gained from listening can have a key role in language acquisition. In this essay， the writer will discuss this question basing on analyzing the nature of listening comprehension，， the skills used in listening comprehension and factors affecting listening comprehension. The writer will also provide some effective ways on teaching listening comprehension.
　　Ⅰ. The nature of listening comprehension
　　Listening is often characterized as a passive skill. Learners are thought of as sponge， passively absorbing the language input provided by textbooks and tapes. However this is misleading， because listening demands active involvement from the hearer. Listening， that is， making sense of what we hear is a constructive process in which the learner is an active participant. The nature of listening means that the learner should be encouraged to engage in an active process of listening for meanings， using not only the linguistic cues but also his non-linguistic knowledge.
　　Ⅱ. The skills used in listening comprehension
　　When the hearer is exposed to the listening materials， he will use two skills：bottom-up and top-down.
　　Bottom-up refers to that part of the aural comprehension process in which the understanding of the ‘heard’ language is worked out proceeding from sounds to words to grammatical relationships in lexical meanings. In the bottom-up part of the listening process， we use our knowledge of language and our ability to process acoustic signals to make sense of the sounds that listening material presents to us， which is a decoding process.
　　Top-down listening infers meaning from contextual clues and from making links between the spoken message and various types of prior knowledge which listeners hold inside their heads. In a word， top-down involves the listener’s ability to bring prior information to bear on the task of understanding the “heard” language.
　　It would be mistaken to see top-down and bottom-up strategies as somehow in opposition. In fact， effective listening needs to add top-down strategies to bottom-up strategies. It is now generally accepted that both function simultaneously and are mutually dependent.
　　Ⅲ. Factors affecting good listening
　　In an English class， students， teacher and listening materials can all become factors affecting good listening.
　　1. How do students affect good listening？
　　Most students are lack of confidence. They try to listen word by word and understand everything. They feel nervous and are afraid of appearing silly by getting the answer wrong. On the other hand， lacking necessary knowledge also inhibits effective listening. In bottom-up strategy， such knowledge includes vocabularies， phrases， and sentence structures etc；while in top-down strategy， if students are lack of the relative ‘prior knowledge’， they will fail to activate schematic knowledge .Without doubt they cannot achieve good listening. Students’ personal emotion also affects good listening. If students are interested in the listening material， they will concentrate on it；if the topic is boring， unfamiliar， students will reject it.