This paper is an attempt to propose a new model of intonation called 'Configurational Contour Model'. For our purpose two previous models are discussed : one is the system of tonetic-stress marks and the other is the theory of pitch levels. To overcome shortcomings which these approaches display, the new model is based on two fundamental characteristics of intonation: (1) that intonation is a suprasyllabic phenomenon; and (2) that intonation is basically a matter of configurations, i.e., of rising, falling and level. Accordingly, the new model can be relatable to relevant aspects of the phonetic representation of utterances and also can express all the tonal oppositions in a given language.

The main purpose of this paper is to examine the rules of phonetic changes in Standard Arabic which keeps the characteristics of phonemes of Proto-Semitic as followings: Assimilation, Dissimilation, Prosthesis, Anaptyxis, Syncope and Contraction, Aphaeresis, and Metathesis.