Abstract: Introduction: Phonological loop which stores and rehearses speech-based information，is an important component in Working Memory Model (Baddeley & Hitch,1974). It consists of two parts: a short-term phonological store with auditory memory traces that are subject to rapid decay and an articulatory rehearsal component that can revive the memory traces. Any auditory verbal information is assumed to enter automatically into the phonological store. Visually presented language can be transformed into phonological code by silent articulation and thereby be encoded into the phonological store. The phonological store acts as an “inner ear”, remembering speech sounds in their temporal order, while the articulatory process acts as an “inner voice” and repeats the series of words on a loop to prevent them from decay. Four main findings provide evidence for the phonological loop: the effect of phonological similarity, the word length effect, the effect of articulatory suppression, and the irrelevant speech. On the basis of these, researchers have done a lot of studies about the role of phonological loop in reading comprehension. Baddeley & Coltheart (1990) used the articulatory suppression paradigm to investigate the relation between phonological loop and reading comprehension; Boyle & Coltheart (1996) used another paradigm—irrelevant speech to explore the role of phonetic code in reading comprehension. But there was not a conclusion of the role of phonological loop in reading comprehension. Therefore, the present study was to investigate the role of phonological in Chinese reading comprehension.
Method: Participants: 45 college students in Experiment 1 and 55 college students in Experiment 2. Materials: 24 texts, each text had 55 words. Design: 2×2×3 mixed design. The first independent variable—reading condition was manipulated between the subjects; the second independent variable—word frequency and the third independent variable—reading edition were both manipulated within the subjects. In Experiment 1, the two levels of reading condition were normal reading condition and articulatory suppression; however, in Experiment 2 were normal reading condition and irrelevant speech. Word frequency had high and low levels both in Experiment 1 and in Experiment 2; reading condition consisted of correct word, similar graphic word, and phonetic word both in Experiment 1 and in Experiment 2. The number of the correct-or-wrong judgment sentences and reaction time were dependent variables. Procedure: In Experiment 1, one half of the participants read the texts in the normal condition; the other half read the texts in the articulatory suppression condition. Once they finished one text study, they should judge whether the meaning of the text was acceptable. In Experiment 2, one half of the participants read the texts in the normal condition; the other half read the texts in the irrelevant speech condition. And the task was the same as in Experiment 1.
Results: Repeated measures of MANOVAs were conducted for Experiment 1 and Experiment 2. In Experiment 1, by the analysis of the correct reading number, there were a main effect of reading condition (F（1，42）=5.18，p<0.05), a main effect of reading edition (F（2，41）=27.98，p<0.001), an interaction between reading condition and reading edition(F（2，41）=3.49，p<0.05), an interaction between reading condition and word frequency(F（1，42）=3.73，p<0.01), an interaction between reading edition and word frequency(F（2，41）=3.68，p<0.05); by the analysis of reaction time, there was only a main effect of reading edition(F（2，25）=9.85，p<0.01). In Experiment 2, by the analysis of correct reading number, there were a main effect of word frequency (F（1，52）=24.24)and a main effect of reading edition(F（2，51）=16.47，p<0.001), but by the analysis of reaction time, there were a main effect of reading condition(F（1，39）=5.61，p<0.05)and a main effect of reading edition(F（2，38）=13.59，p<0.001).
Conclusions: According to the findings of this study, we draw conclusions as follows: (1) Both the articulatory control process and the articulatory store play an important role in Chinese reading. (2) Phonetic code and Graphic code effect Chinese reading in different process, and the role of phonetic code is more significant. (3) There are relations between word frequency and articulatory loop. The articulatory control process plays an evident role in high frequency words. (4) Word frequency has connections with graphic code and phonetic code. In low frequency words, the role of graphic code is more evident than phonetic c

Key words: phonological loop, articulatory suppression, irrelevant speech, word frequency