This article provides the first formal account of empirical generalizations concerning the adaptation of Japanese vowels in Truku, an Austronesian language spoken in Taiwan. It is shown that while most Truku native markedness constraints are respected in loanword adaptation, two of the language's markedness constraints are sacrificed to satisfy loanword-sensitive faithfulness constraints and one is blocked only in unaffixed loanwords, exhibiting a derived environment effect. Other than native phonology, perceptual saliency is also shown to play a role in loanword adaptation, as evidenced by the different adaptation behaviors between voiced and voiceless vowels and between peripheral and mid vowels. The fact that both perception and native phonology play roles in vowel adaptation in Truku loanwords thus supports the Perception-Phonology Approach of loanword adaptation, a perception-oriented theory that involves the native phonology.
