Acoustic-Emergent Phonology in the Amplitude Envelope of Child-Directed Speech
Acoustic-Emergent Phonology in the Amplitude Envelope of Child-Directed Speech
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DOI：
10.1371/journal.pone.0144411
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发表时间：
2015-12-07
期刊：
影响因子：
3.7
通讯作者：
Goswami, Usha
中科院分区：
文献类型：
--
作者：
Leong, Victoria;Goswami, Usha
当获得语言时，幼儿可以使用语音中的声学频谱-时间模式来推导口语中的语音单位（例如，韵律重音模式、音节、音素）。儿童在没有直接指导的情况下，似乎能够快速学习声学-语音映射，但其潜在的发展机制仍不清楚。在不同的语言中，振幅包络敏感性和语音发展之间的关系已经被发现，这表明儿童可能利用包络内的振幅调制（AM）模式来发展语音系统。在这里，我们提出了频谱幅度调制相位层次（S-AMPH）模型，这是一组用于推导儿童指导语音（CDS）中主导AM模式的算法。使用主成分分析，我们表明，节奏CDS包含一个AM层次结构，包括3个核心调制时间尺度。这些时间尺度对应于关键的语音单位：韵律重音（重音AM，类似于2 Hz），音节（音节AM，类似于5 Hz）和起始韵单位（音素AM，类似于20 Hz）。我们认为，这些AM模式可以在原则上由天真的听众计算没有词汇知识的声学语音映射。然后，我们证明，调制统计在这个AM层次结构中的语音信号解析成一个原始的分层组织的音韵系统，包括应力脚（原词），音节和首韵单位。我们将S-AMPH模型应用于另外两个CDS语料库，一个是自发的，一个是故意定时的。该模型准确地识别了72-82%（自由阅读的CDS）和90-98%（节奏规则的CDS）的重音模式，音节和首韵单位。这种从语音AM中提取原始音系的原理性论证被称为声学涌现音系学（AEP）理论。AEP理论提供了一套方法来研究早期语音发展是如何被跨语言的语音时间调制结构所塑造的。S-AMPH模型揭示了压力足（AM类似于2 Hz）的关键发育作用。压力足支撑着不同的语言节奏类型学，而言语节奏支撑着婴儿在所有语言中的语言习得。
When acquiring language, young children may use acoustic spectro-temporal patterns in speech to derive phonological units in spoken language (e.g., prosodic stress patterns, syllables, phonemes). Children appear to learn acoustic-phonological mappings rapidly, without direct instruction, yet the underlying developmental mechanisms remain unclear. Across different languages, a relationship between amplitude envelope sensitivity and phonological development has been found, suggesting that children may make use of amplitude modulation (AM) patterns within the envelope to develop a phonological system. Here we present the Spectral Amplitude Modulation Phase Hierarchy (S-AMPH) model, a set of algorithms for deriving the dominant AM patterns in child-directed speech (CDS). Using Principal Components Analysis, we show that rhythmic CDS contains an AM hierarchy comprising 3 core modulation timescales. These timescales correspond to key phonological units: prosodic stress (Stress AM, similar to 2 Hz), syllables (Syllable AM, similar to 5 Hz) and onset-rime units (Phoneme AM, similar to 20 Hz). We argue that these AM patterns could in principle be used by naive listeners to compute acoustic-phonological mappings without lexical knowledge. We then demonstrate that the modulation statistics within this AM hierarchy indeed parse the speech signal into a primitive hierarchically-organised phonological system comprising stress feet (proto-words), syllables and onset-rime units. We apply the S-AMPH model to two other CDS corpora, one spontaneous and one deliberately-timed. The model accurately identified 72-82% (freely-read CDS) and 90-98% (rhythmically-regular CDS) stress patterns, syllables and onset-rime units. This in-principle demonstration that primitive phonology can be extracted from speech AMs is termed Acoustic-Emergent Phonology (AEP) theory. AEP theory provides a set of methods for examining how early phonological development is shaped by the temporal modulation structure of speech across languages. The S-AMPH model reveals a crucial developmental role for stress feet (AMs similar to 2 Hz). Stress feet underpin different linguistic rhythm typologies, and speech rhythm underpins language acquisition by infants in all languages.