Tsao Feng-Ming
Department of Psychology, National Taiwan UniversityTaipei, Taiwan.
Front Psychol. 2017 Apr 11;8:558. doi: 10.3389/fpsyg.2017.00558. eCollection 2017.
To learn words in a tonal language, tone-language learners should not only develop better abilities for perceiving consonants and vowels, but also for lexical tones. The divergent trend of enhancing sensitivity to native phonetic contrasts and reduced sensitivity to non-native phonetic contrast is theoretically essential to evaluate effects of listening to an ambient language on speech perception development. The loss of sensitivity in discriminating lexical tones among non-tonal language-learning infants was apparent between 6 and 12 months of age, but only few studies examined trends of differentiating native lexical tones in infancy. The sensitivity in discriminating lexical tones among 6-8 and 10-12 month-old Mandarin-learning infants ( = 120) was tested in Experiment 1 using three lexical tone contrasts of Mandarin. Facilitation of linguistic experience was shown in the tonal contrast (Tone 1 vs. 3), but both age groups performed similar in the other two tonal contrasts (Tone 2 vs. 4; Tone 2 vs. 3). In Experiment 2, 6-8 and 10-12 month-old Mandarin-learning infants ( = 90) were tested with tonal contrasts that have pitch contours either similar to or inverse from lexical tones in Mandarin, and perceptual improvement was shown only in a tonal contrast with familiar pitch contours (i.e., Tone 1 vs. 3). In Experiment 3, 6-8 and 10-12 month-old English-learning infants ( = 40) were tested with Tone 1 vs. 3 contrast of Mandarin and showed an improvement in the perception of non-native lexical tones. This study reveals that tone-language learning infants develop more accurate representations of lexical tones around their first birthday, and the results of both tone and non-tone language-learning infants imply that the rate of development depends on listening experience and the acoustical salience of specific tone contrasts.
为了学习声调语言中的词汇，声调语言学习者不仅要提高感知辅音和元音的能力，还要提高感知词汇声调的能力。增强对母语语音对比的敏感性和降低对非母语语音对比的敏感性这一不同趋势，对于评估听周围语言对语音感知发展的影响在理论上至关重要。非声调语言学习婴儿在辨别词汇声调方面的敏感性丧失在6至12个月大时很明显，但只有少数研究考察了婴儿期辨别母语词汇声调的趋势。在实验1中，使用普通话的三种词汇声调对比，测试了6至8个月和10至12个月大的学习普通话的婴儿（=120）辨别词汇声调的敏感性。在声调对比（第一声与第三声）中显示出语言经验的促进作用，但在其他两种声调对比（第二声与第四声；第二声与第三声）中，两个年龄组的表现相似。在实验2中，对6至8个月和10至12个月大的学习普通话的婴儿（=90）进行了具有与普通话词汇声调相似或相反音高轮廓的声调对比测试，并且仅在具有熟悉音高轮廓的声调对比（即第一声与第三声）中显示出感知改善。在实验3中，对6至8个月和10至12个月大的学习英语的婴儿（=40）进行了普通话第一声与第三声对比的测试，结果显示他们对非母语词汇声调的感知有改善。这项研究表明，学习声调语言的婴儿在一岁左右对词汇声调形成了更准确的表征，声调语言和非声调语言学习婴儿的结果都表明，发展速度取决于听力经验和特定声调对比的声学显著性。
