The prominent role of allophonic cues in English speech segmentation has widely been recognized by phonologists and psycholinguists. However, very meager inquiry was devoted to analysing the perception of these noncontrastive allophonic cues by Arab EFL learners. Accordingly, the present study is an attempt to examine the exploitation of allophonic cues, mainly aspiration, glottalization and approximant devoicing to English word junctures by 40 Jordanian PhD students. Moreover, it aims to find out which allophonic cues are perceived more accurately during the segmentation process and if there is any evidence for Universal Grammar markedness. The experiment is led through a forced-choice identification task adopted from Altenberg (Second Lang Res 21:325-358, 2005) and Rojczyk et al. (Res Lang 1:15-29, 2016). The results of ANOVA unveiled that there is a statistically significant difference between the three types of allophonic cues, viz. aspiration, glottalization and approximant devoicing. This implies that the participants outperformed in stimuli marked by glottalization than by aspiration and approximant devoicing. This result provided further evidence for the universality of glottalization as a boundary cue in English speech segmentation. Overall, the Jordanian PhD students failed in perceiving the allophonic cues accurately and exploiting them to detect word boundaries. The present inquiry has the potential to provide several recommendations for syllabus designers, and second/foreign language teachers and learners.