Effect of Arabic emphaticness on Voice O\NET Time (VOT)

In the speech signals of many languages, including Arabic, Voice Onset Time (VOT) is a key feature of stop phonemes. VOT can be utilized by a person's auditory system to distinguish between voiced and unvoiced stops such as /p/ and /b/ in the case of English. Similarly, VOT can be adopted by digital systems to classify and recognize stop phonemes in order to find dissimilarities and to determine the correct message especially for different words carrying phonemes with very high degrees of similarity. In this work we focused on the effect of the emphaticness property on VOT values in Modern Standard Arabic (MSA) language. The emphatic stop phonemes in MSA are /d?/ and /t?/, while their nonemphatic counterparts are /d/ and /t/. A database was built using carrier words with a syllable structure of CV-CV-CV and an MSA dialect uttered by speakers of good Arabic. We concluded from our investigation that the property of emphaticness decreases VOT values if compared with the VOTs of nonemphatic counterparts. This was observed with a large difference in all Arabic emphatic stops and for all samples. Hence, this conclusion can be used for detecting the emphaticness properties in Arabic stops.