Effects of the Working Memory Capacity and Language Proficiency on L2 Learners#8217; Listening Comprehension 工作记忆容量和语言水平对二语习得中听力理解的影响 1. Introduction For decades, researchers and practitioners alike have been interested in predicting which learners are likely to succeed in acquiring a foreign language (L2). A variety of variables have been proposed and explored empirically (for a review, see Dornyei, 2006), with the goal of identifying separable components of language learning ability#8212;that is, language aptitude (Dornyei, 2005; Skehan, 2002). Working memory (WM) has been identified as being likely contributors to language aptitude (e.g., DeKeyser amp; Koeth, 2011; Hummel, 2009; Wen amp; Skehan, 2011). Listening is a key skill in second or foreign languages (L2/ FL); it plays a critical role in communication and in second language acquisition (Anderson and Lynch, 1988; Rost, 1990). Rost (1994) pointed out that listening is vital in the language classroom because it provides input for the learners. Therefore, exploring L2 learners#8217; listening comprehension is of much concern. A number of studies have reported relationships between WM and aspects of L2 learning (see Juffs amp; Harrington, 2011, for a comprehensive review). However, only Sagarra (2000) has examined the longitudinal effects of WM in classroom second language acquisition, and none has investigated the predictive utility of WM and language proficiency together within Two-Way ANOVA. Thus, the current study sought to provide preliminary evidence of the predictive validity of these two executive functions as a first step in a research program. 2.Literature Review 2.1. Working memory capacity First put forward by Baddeley and Hitch in 1974, working memory is defined as part of the human memory system that combines the temporary storage and manipulation of information in the service of cognition. The central executive, phonological loop and visuospatial sketchpad, the three relatively independent components, make working memory a complicated system. Working memory has a limited capacity and is a working space where human conducts cognitive activities such as understanding, learning and deducting. 2.2 Language proficiency Language proficiency is the ability of an individual to speak or perform in an acquired language. As theories among pedagogues as to what constitutes proficiency go (Archived April 8, 2005), there is little consistency as to how different organizations classify it. Additionally, fluency and language competence are generally recognized as being related, but separate controversial subjects. In predominant frameworks in the United States, proficient speakers demonstrate both accuracy and fluency, and use a variety of discourse strategies. Thus, native speakers of a language can be fluent without being considered proficient. Native-level fluency is estimated to be between 20,000#8211;40,000 words, but basic conversational fluency might only require as little as 3,000 words. 2.3 Empirical studies In recent years, listening comprehension is widely considered to be of great importance in second language learning and there is much research done on L2 listening comprehension from the perspective of working memory at home and abroad. Researchers have been attempting to track down evidence on the extent to which working memory capacity is related to learners#8217; performance and development of L2 listening comprehension (A. Was, 2007; Andringa et al., 2012 ; Wu, 2002; Wang, 2008; Chen, 2008; Gu, 2007). Was A. (2007) reexamines the relationship between working memory capacity and listening comprehension and emphasizes the important role of available long-term memory. Through the experiment, the analyses reveal that available long-term memory mediates the relationships of both working memory and background knowledge with listening Comprehension. In Andringa et al. (2012) study, they aim to find out which factors explain success in native and non-native listening comprehension. 121 native and 113 non-native speakers of Dutch are involved in the experiment. In their study, they adopt four digit span tasks and one non-word recognition task to measure the subjects#8217; verbal working memory capacity. Structural equation modeling is used to identify the predictors of individual differences in listening comprehension. It is manifested by some of the test#8217; s results that working memory does not explain unique variance in listening comprehension in either group, whereas knowledge is proved to be the determinant of success in listening comprehension by both native and non-native speakers. 2.4 Limitations of previous studies In recent years, research on working memory capacity has mainly focused on three dimensions including language input, output and the combination of both. The present study sets about investigating the effect of working memory capacity and language proficiency on L2 learners#8217; listening comprehension. On the whole, previous related research is featured by applying the most widely used working memory capacity tests, inconsistent results owing to the small quantity of studies and different research designs, and the lack of the combination of working memory capacity and language proficiency. Firstly, there is not enough statistical evidence to support the researchers#8217; findings. Although many scholars have conducted research on the effective factors of L2 learners#8217; listening comprehension and put forward a lot of valuable results, there are still many arguments about the findings. Thus, more systematic research is needed to shed light into the relationship between L2 listening comprehension and its effective factors. Secondly, the working memory capacity test in previous studies needs to be improved, especially in non-English speaking countries. Slight differences in L2 language proficiency may have an enormous impact on the different dimensions of L2 speech production. It is methodologically problematic to assume that in a group everyone has the same or an approximate proficiency level and it is necessary to control for the subject#8217;s language proficiency by a proficiency test.