Previous studies in speech production and acquisition have mainly focused on how feedback vs. goals and feedback vs. prediction regulate learning and speech control. The present study investigated the less studied mechanism-prediction vs. goals in the context of adult Mandarin speakers' acquisition of non-native sounds, using an auditory feedback masking paradigm. Participants were asked to learn two types of non-native vowels: /ø/ and /ɵ/-the former being less similar than the latter to Mandarin vowels, either in feedback available or feedback masked conditions. The results show that there was no significant improvement in learning the two targets when auditory feedback was masked. This suggests that motor-based prediction could not directly compare with sensory goals for adult second language acquisition. Furthermore, auditory feedback can help achieve learning only if the competition between prediction and goals is minimal, i.e., when target sounds are distinct from existing sounds in one's native speech. The results suggest motor-based prediction and sensory goals may share a similar neural representational format, which could result in a competing relation in neural recourses in speech learning. The feedback can conditionally overcome such interference between prediction and goals. Hence, the present study further probed the functional relations among key components (prediction, goals and feedback) of sensorimotor integration in speech learning.