Every language makes its own articular selection from the range of possible speech sounds and organizes them into a system of contrasts and patterns. This system makes up a language"s phonology. Phonology analysis takes place at three levels. First and most obviously, the flow of speech can be divided into individual speech sounds, also known as segments. On the one hand, segments are grouped together into larger structural units known as syllables, which usually consist of a vowel along with any consonants associated with it. On the other hand, segments can also be broken down into a smaller components called features, which correspond to articulatory and/or acoustic categories such as (+- voice) or (+- nasal) One of the most important observations in the study of human language is that some sounds contrast with each other in that they can be used to distinguish between words, and some don"t.