When intake exceeds input: Language specific perceptual illusions induced by L1 prosodic constraints

In this paper we argue that the prosodic well-formedness conditions of a learner's native language phonology interfere with accurate perception of non-native segmental sequences. This interference induces a perceptual illusion effect due to which learners perceive an illusory vowel that, in fact, does not exist in the acoustic signal. In this way, a learner's percept of the L2 input, or L2 intake, actually includes more segmental material than is physically present. As a product of the native language phonology, these perceptual illusions are shown to occur only in environments where L2 segmental sequences cannot be licensed by L1 prosodic constituents. In addition, the quality of the perceived illusory vowel is shown to coincide with the vowel category inserted by a learner's native language phonology in environments conditioning epenthesis. Finally, by varying the duration of interstimulus intervals in an AX discrimination task, we reveal latent capacities to overcome the perceptual illusion effect when finer grained acoustic representations are made accessible. We conclude that perception of illusory segments is a direct result of a learner's native language phonology generating a phonological representation that abides by the prosodic constraints of the learner's native language.