Abstract: The previous study has found that early-acquired words processed more quickly or accurately than late-acquired words, which was defined as Age of Acquisition (AOA). So far, four major theories focused on the processing mechanism of AOA: ⑴ Phonological Completeness Hypothesis believed that the phonology of early-acquired word was stored as a whole, while the phonology of late-acquired word was assumed to be represented in a more fragmented form. In this case, a processing cost was produced because the later-acquired word was more difficult to assemble for pronunciation; ⑵ Semantic Hypothesis supposed that the late acquired word was learned on the basis of the early acquired word, and because of the repeatedly processing of early-acquired word meaning, then they were processed faster and more accurately than late-acquired words;⑶Arbitrary Mapping Hypothesis assumed that AOA effect reflected the arbitrary nature of the mapping between input (e.g. orthographic) and output (e.g. phonological or semantic) representation form during the development of lexical network. When the mapping between input and output is inconsistent, or arbitrary, AOA effect would be increased. While the mapping between input and output is highly consistent, AOA effects would be reduced; ⑷ Cumulative Frequency Hypothesis. If the frequency of a word’s application was higher, then the word would be processed more quickly. And because we used the early-acquired word more frequently, then our processing speed was faster for early-acquired word than for late-acquired word. Recently, there were growing evidences showed that AOA effect was found in the processes of orthography, phonology and semantic, which supported Arbitrary Mapping Hypothesis. In factual life experience, words are learned by hearing more than by reading, and the age of acquisition might be earlier. In order to test the Arbitrary Mapping Hypothesis of AOA effects in auditory words, three experiments were conducted to examine the locus of the age of acquisition effects in the processing of Chinese words. In Experiment 1, auditory words were divided into early group and late group, participants were required to judge whether the later presented visual character pronounced the same as the earlier presented auditory word. The result showed that words acquired early were processed more accurately than words acquired late. In Experiment 2 and 3, the participants were asked to judge whether the later presented visual character possessed similar orthography or relevant meaning with the earlier presented auditory word. In both of the two experiments, the reaction time of early acquired Chinese character turned out to be faster than that of late acquired, which indicated AOA effects. The study results supported Arbitrary Mapping Hypothesis. On one hand, the AOA effects produced in the processes of orthography, phonology and semantic. On the other hand, the mapping level was one of factors which determined AOA.

Key words: age of acquisition, auditory word, arbitrary mapping hypothesis

摘要： 通过三个实验考察听觉词汇的获得年龄效应。实验1采用基于语音的词汇判断任务，在错误率上存在词汇获得年龄效应，即早期习得词汇的正确率高于晚期习得词汇；实验2、3分别采用基于字形和语义的词汇判断任务，在反应时上存在词汇获得年龄效应，即早期习得词汇的反应快于晚期习得词汇。结果支持任意映射假说的观点：⒈词汇获得年龄效应产生于音、形、义加工的多个方面；⒉映射程度高低是决定词汇获得年龄效应大小的重要因素。

关键词: 词汇获得年龄, 听觉词汇, 任意映射假说