1. Introduction

Listening is a crucial language skill and it plays a vital role in the language acquisition process. Listening comprehension is a complicated cognitive process that acquires a large amount of effort especially in a foreign language learning process. Therefore, its development is of prime concern to EFL learners and language teachers.

Recently, with the advances in multimedia technology, audiovisual materials (TV programs, movies, video, etc.) have been promoted and exploited as abundant language learning resources. These multimedia environments have not only helped to make instructional materials more authentic, but also offered listening support by means of a ”technological overlay” (Robin. 2007, P.109), such as scripts and on-screen text. One special type of on-screen text is captioning, referred to unilingual or multilingual subtitling. Researchers have gained inspiring results concerning the effectiveness of captioning for intensifying EFL learners#8217; listening comprehension. Yet, the generalizability of much research on captioning is problematic for three main reasons. First of all, studies have performed experiments on participants from different countries and cultures. Second, studies have focused on the effectiveness of captions for different proficiency levels. Third, studies have measured different components of listening and have used different tests to do so.

This study explored the effect of the presence or absence of different video subtitles on the university-level Chinese EFL students#8217; listening comprehension. A total of 56 junior students taught in English from Nanjing Tech University will be tested in their listening abilities through pretest and two posttests. Accordingly, the two following research questions were addressed in this study:

1. Is there any effect of video captioning on Chinese EFL learners#8217; listening comprehension?

2. Does the effect of video captioning on listening comprehension vary according to the different forms of video captioning?

2. Literature Review

The background research section first provides a rationale for using captioned video (Section 2.1), before discussing the main benefits and issues studied in captioning literature (Section 2.2).

2.1 Theoretical issues of using captioned video

A rationale for using captioned video can be found in (1) research on multimedia materials, (2) research on listening comprehension, and (3) the dual-coding theory.

(1) With the emergence of multimedia programs, initial research studies on the use of audiovisual material for listening skill development generally focused on the effectiveness of video by comparing it to traditional audio use. The use of video was found to ”enrich target language processing” (Meskill, 1996, p. 196) and to improve listening ability (Brett, 1997; Secules et al., 1992; Terrell, 1993), vocabulary acquisition (Brett, 1998; Duquette and Painchaud, 1996), and oral proficiency (Hung, 2009). However, although video may present learners with”contextually rich materials” (Baltova, 1999a, p. 34), the language and images presented in the video do not necessarily enhance comprehension (Danan, 2004) or provide opportunities for learning (Baltova, 1999a).

Chapelle (2003) argued that input can be made more comprehensible by modifying it. Research questions on multimedia use thus no longer ask whether or not to use video, but rather how to present video materials in an efficient way (Baltova, 1994). Hence, researchers have investigated the potential of adding on-screen text in the form of traditional native language (L1) subtitles, reversed subtitles (L2 text, L1 video), captioning (L2 video, L2 text), and keyword captioning (L2 video, L2 keywords) and have reported overall positive results concerning their effectiveness (e.g. Danan, 1992; Markham, 2001; Winke et al., 2010).

(2) Listening comprehension has often been defined as one of the most complex skills in language learning (Oxford, 1993). Because of its real-time nature (Buck, 2001), learners cannot control the speed of the input, which leaves them with ”fewer opportunities to invoke time-consuming explicit knowledge than do the other skills” (Hulstijn, 2007, p. 791). This may cause a series of problems, such as speech stream chunking, decoding, and interpretation (Goh, 2000; Graham, 2006; Rost, 2002), which are related to the lack of automated word recognition (de Groot and van Hell, 2005). Research has also suggested that successful listening is highly correlated with learners#8217; vocabulary size (Staehr, 2009; Webb and Rodgers, 2009). Yet, L2 learners have generally not developed a sufficiently broad vocabulary to successfully cope with aural input. Hence, researchers have looked at the potential of using on-screen text and captioning more in particular (Markham, 1989; Neuman and Koskinen, 1992; Price, 1983; Vanderplank, 1988), as a means to outweigh deficient vocabulary size and overcome listening problems, while at the same time exposing the learner to the aural and written version of the L2. In this perspective, captioning has been proposed as some kind of ”mediating device” (Vanderplank, 1988, p. 280), assisting the learner visually where listening skills fall short.