Experimental study of emphasis and voicing in the plosives of Yemeni Spoken Arabic with some implications for foreign language teaching and learning.

This is an experimental study of two major distinctive features: emphasis and voicing in the plosives of Yemeni Spoken Arabic. It investigates some of their acoustic, perceptual and arodynamic correlates and aims, at least in part, to find the language-specific aspects in as far as these phonetic phonemena are concerned. It falls into two related parts.
Part One consists of two chapters. Chapter one gives a general background of YSA with special reference to the phonemic significance of emphasis and voicing in the plosives and their interaction with various contextual factors and positions. Phonological definitions of these features are given. Various theoretical approaches are also dealt with. The syllable structure and the stress patterns in both Modern Standard Arabic and Yemeni Spoken Arabic are presented. Chapter two reviews critically some of the hypotheses and interpretations of voicing mechanisms and the factors affecting their realizations in various languages. Some of the relevant aspects reviewed are voice onset time in various languages, formant transitions, closure durations, temporal relationship between consonants and vowels, categorical perception and the phoneme boundary, aerodynamic factors and their role in the production of plosives. The two features are also reviewed in relation to vocalic context, place of articulation, stress, gemination and phonetic position.
Part Two consists of four chapters representing the main body of this study. Chapter three is an investigation of the acoustic characteristics of the voiced/voiceless and emphatic/nonemphatic categories in words embedded in a contextual frame sentence. Chapter four is a perceptual investigation of the above contrasts by means of synthetically generated speech using the Klatt Synthesizer. It examines the role played by VOT, the relative onset time between the release and the onset of voicing, in the accurate identification of the voicing cognates. Another experiment attempts to evaluate the role of the second formant particularly its onset frequency and steady state portion in the emphatic/nonemphatic distinction. The relationships between perception and production are described and the theory of 'categorical perception' in relation to our data is also discussed.
Chapter five investigates aerodynamic patterns and aerodynamically derived estimates of articulation for the emphatic/nonemphatic and the voiced/voiceless consonants in two experiments. Since there are several variables involved in this investigation, the results in both experiments are subjected to analyses of variance to obtain the effects of the independent variables on the dependent ones.
In chapter six the findings of the previous three chapters are summarized. Some implications for foreign language teaching and learning are also discussed. The study ends with a section on the limitations and suggestions for future research.