Nittrouer Susan, Lowenstein Joanna H
Lang Speech. 2014 Dec;57(Pt 4):487-512. doi: 10.1177/0023830913508075.
The dynamic specification account of vowel recognition suggests that formant movement between vowel targets and consonant margins is used by listeners to recognize vowels. This study tested that account by measuring contributions to vowel recognition of dynamic (i.e., time-varying) spectral structure and coarticulatory effects on stationary structure. Adults and children (four- and seven-year-olds) were tested with three kinds of consonant-vowel-consonant syllables: (I) unprocessed; (2) sine waves that preserved both stationary coarticulated and dynamic spectral structure; and (3) vocoded signals that primarily preserved that stationary, but not dynamic structure. Sections of two lengths were removed from syllable middles: (I) half the vocalic portion; and (2) all but the first and last three pitch periods. Adults performed accurately with unprocessed and sine-wave signals, as long as half the syllable remained; their recognition was poorer for vocoded signals, but above chance. Seven-year-olds performed more poorly than adults with both sorts of processed signals, but disproportionately worse with vocoded than sine-wave signals. Most four-year-olds were unable to recognize vowels at all with vocoded signals. Conclusions were that both dynamic and stationary coarticulated structures support vowel recognition for adults, but children attend to dynamic spectral structure more strongly because early phonological organization favors whole words.
元音识别的动态规范理论认为，听者利用元音目标与辅音边界之间的共振峰移动来识别元音。本研究通过测量动态（即时变）频谱结构以及协同发音对静态结构的影响对元音识别的贡献，来验证这一理论。对成人和儿童（4岁和7岁）进行测试，使用三种辅音 - 元音 - 辅音音节：（1）未处理的；（2）保留了静态协同发音和动态频谱结构的正弦波；（3）主要保留静态但不保留动态结构的声码信号。从音节中间去除了两种长度的部分：（1）元音部分的一半；（2）除了前三个和后三个音高周期之外的所有部分。只要音节剩余一半，成人对未处理和正弦波信号的识别就很准确；他们对声码信号的识别较差，但高于随机水平。7岁儿童在两种处理信号下的表现都比成人差，但在声码信号下比在正弦波信号下差得更多。大多数4岁儿童根本无法识别声码信号中的元音。结论是，动态和静态协同发音结构都支持成人的元音识别，但儿童更关注动态频谱结构，因为早期的语音组织更倾向于整个单词。
