Decoding training is an approach to teaching listening skills to help learners develop the ability to recognize individual words from speech. Although it has been historically underemphasized, recent empirical studies have pointed to its potential value in listening education. However, instructors and students generally face certain challenges when developing decoding skills. In this study, we used a meta-synthesis approach to examine all available empirical studies and identify five main challenges in decoding training: (a) insufficient time and practice, (b) student disengagement, (c) cognitive overload, (d) undifferentiated learning, and (e) ineffective feedback. We also discuss how technology was used in these studies to address these challenges. Finally, we identify several gaps in technology-assisted decoding training and offer recommendations for future research.