复习资料（2.1）
1、 The phonic medium of language
语言的声音媒介
Speech and writing are the two media used by natural languages as vehicles for communication. Of the two media of language, speech is more basic than writing. Speech is prior to writing. The writing system of any language is always “invented” by its users to record speech when the need arises.
For linguists, the study of sounds is of greater importance than that of writing.
The limited ranges of sounds which are meaningful in human communication and are of interest to linguistic studies are the phonic medium of language (语言的声音媒介) . The individual sounds within this range are the speech sounds （语音）.