Early learners' discrimination of second-language vowels

Area of Science:

• Psycholinguistics
• Auditory Perception
• Second Language Acquisition

Background:

• The extent of perceptual system plasticity after native language (L1) sound system attunement remains unclear.
• Understanding second-language (L2) vowel discrimination is crucial for assessing auditory plasticity in adults.

Purpose of the Study:

• To evaluate L2 vowel discrimination in early L2 learners.
• To investigate the impact of native language (L1) attunement on perceptual plasticity for L2 sounds.

Main Methods:

• An AXB test was used to assess English vowel discrimination by native Spanish early learners and monolingual Spanish and English speakers.
• Experiments were conducted with varying interstimulus intervals (ISIs) of 1000 ms and 0 ms.
• Procedures were optimized to reduce discrimination scores for challenging foreign vowel contrasts.

Main Results:

• Native Spanish monolinguals performed at near-chance levels on difficult English vowel contrasts.
• Early learners demonstrated considerable perceptual learning, achieving high discrimination scores, similar to English monolinguals.
• Significant differences between early learners and English monolinguals at a 0-ms ISI suggest incomplete perceptual plasticity.

Conclusions:

• Early second-language learners exhibit substantial perceptual learning in discriminating L2 vowels.
• Native language attunement may limit the plasticity of the perceptual system for L2 sound contrasts.
• Auditory systems of early L2 learners are not identical to those of native speakers, even after extensive exposure.