Younger learners are better at acquiring second-language (L2) phoneme contrasts than are older learners, but this general correlation between age and learning ability is often confounded with factors such as how late learners use their L2 in daily life. The present study trained Japanese speakers across a wide age range (young children through adults) on English /r/-/l/, using a computer-based high variability phonetic training program, in order to control the /r/-/l/ inputs across age during the training period. The results demonstrated that training improved Japanese speakers’ perception and production of the English /r/-/l/ contrast, and age affected their improvement in perception. Over the 10 training sessions, younger learners (children and adolescents) improved their perception more than adult learners, suggesting that L2 phoneme learning may indeed decline with age. Children did not improve their identification, perceptual sensitivity to the primary acoustic cue (F3), and category discrimination as much as adolescents, possibly due to their immature cognition and phonemic awareness.

年轻的学习者比年长的学习者更擅长获得第二语言 (L2) 音素对比，但年龄和学习能力之间的这种普遍相关性往往与晚学习者在日常生活中使用 L2 的时间等因素混淆。本研究使用基于计算机的高可变性语音训练计划，使用英语 /r/-/l/ 对各个年龄段（幼儿到成人）的日语使用者进行培训，以控制 /r/-/l/训练期间跨年龄的输入。结果表明，培训提高了日本人对英语/r/-/l/对比的感知和产生，年龄影响了他们感知的提高。在 10 次培训课程中，较年轻的学习者（儿童和青少年）比成人学习者提高了他们的感知能力，表明二语音素学习确实会随着年龄的增长而下降。儿童的识别能力、对主要声学线索 (F3) 的感知灵敏度和类别辨别能力没有像青少年一样提高，这可能是由于他们的认知和音素意识不成熟。