Pronunciation modeling for dialectal arabic speech recognition

Short vowels in Arabic are normally omitted in written text which leads to ambiguity in the pronunciation. This is even more pronounced for dialectal Arabic where a single word can be pronounced quite differently based on the speaker´s nationality, level of education, social class and religion. In this paper we focus on pronunciation modeling for Iraqi-Arabic speech. We introduce multiple pronunciations into the Iraqi speech recognition lexicon, and compare the performance, when weights computed via forced alignment are assigned to the different pronunciations of a word. Incorporating multiple pronunciations improved recognition accuracy compared to a single pronunciation baseline and introducing pronunciation weights further improved performance. Using these techniques an absolute reduction in word-error-rate of 2.4% was obtained compared to the baseline system.