The effect of Arabic emphaticness on Voice Time Onset (VOT)

In speech signal of many languages, including Arabic, Voice Onset Time (VOT) is a key feature of stop phonemes. VOT can be utilized by human being auditory system to distinguish between voiced and unvoiced stops such as /p/ and /b/ in case of English. In a similar case, VOT can be adopted by digital systems to classify and recognize stop phonemes in order to find dissimilarities and to figure out the correct message especially in case of different words carrying phonemes with very high similarities. In this work we focused on effect of emphaticness property on VOT values in Modern Standard Arabic (MSA) language. The emphatic stop phonemes in MSA are /d^?/ and /t^?/ with their nonemphatic counterparts are /d/ and /t/, respectively. A database was built using carrier words having syllable structure of CV-CV-CV and MSA dialect uttered by good Arabic speakers. We concluded from our investigation that emphaticness property decreases VOT values if compared with VOTs of nonemphatic counterparts. This observation was noticed in all Arabic emphatic stops and for all samples and with large difference. Hence, this conclusion can be used in detecting the emphaticness properties in Arabic stops.