This research-based book presents a study that examined the impact of explicit instruction in phonetics and the phonologies of English and Arabic on the development of sound production and recognition skills. The study utilized an intervention strategy that introduced the sounds and letters of Arabic to two groups of adult English-speaking learners of Arabic. The data strongly suggest that including an introductory component to articulatory phonetics and the phonologies of the first and target languages improves sound production and sound recognition skills of adult foreign language learners. These results are based on quantitative and qualitative data analysis and show statistically consistent differences in the sound production and sound recognition skills of the students in the two groups, with the students in the experimental group achieving higher scores than the students in the control group. The book provides recommendations for students, teachers, and curriculum developers.