This dissertation explores the phonetics and phonology of voicing and emphatic assimilation across morpheme boundaries and investigates gemination word-medially and word-finally in Rural Jordanian Arabic (RJA). The results reveal that assimilation across morpheme boundaries behaves differently from assimilation across word boundaries in RJA. Vowel duration and vowel F1 were found robust parameters to indicate voicing assimilation. Similarly, F1, F2, and F3 were also adequate correlates to indicate emphatic assimilation. Phonologically, assimilation is best accounted for through the Sonority Hierarchy, Notion of Dominance, and Obligatory Contour Principle. For gemination, consonant as well as vowel durations were found robust acoustic correlates to discriminate geminates from singletons. Phonologically short vowels in the geminate context are significantly shorter than those in singleton context, while phonologically long vowels in geminate context are significantly longer than those in singleton context. The results indicate that the proportional differences between geminates and singletons based on word position and syllable structure are significantly different. Geminates word-medially are one and a half times longer than geminates word-finally. It has also been found that there is a temporal compensation between geminate consonants and the preceding vowels. Phonologically, geminates are best accounted for through prosodic weight rather than prosodic length. / October 2016