In the present work, we present our Arabic Semi-Syllable Synthesizer. The work consists of seven steps: (1) building a Semi-Syllable Speech Database for Arabic Semi-Syllable Synthesizer, (2) building the Natural Language Processing Module which comprises a Text Pre-processing Module and a Text to Phoneme conversion using Arabic Transcription from Orthographic to Phonemes, (3) followed by a Phoneme to Semi-Syllables Mapping using a Syllabification Expert System, (4) an Acoustic Word Stress Analysis for Continuous Arabic Speech based on the three prosodic parameters (fundamental frequency, intensity, duration) in order to detect stressed syllables.