Asymmetry of Production and Perception

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are not equivalent enough to contend for problems we have configured so far. Liao (2006), in addition to the above study, has also provided a model of the English vowels structures produced by Taiwan EFL learners. The problem of both of these studies is that only a general mean value is provided for each vowel, and no values are provided by all of the levels of the learners in the studies.

2.2 Asymmetry of Production and Perception

L2 learners show an asymmetrical behavior in the production and perception of vowels (e.g., Best, 1995; Y. Chen et al., 2001; Flege, 1995; Flege, Bohn, & Jang, 1997;

among many others). A number of scholars have found that Taiwan Mandarin speakers are able to perceive most English vowels but fail to produce them all in a native-like way (e.g., Chang, 2007; L.-M. Chen, Chang, Yang, & Chou, 2006; Lai, 2005; C.-Y. Lin, 2013). Although the focus of the research and the test items of these studies differ, they all contribute to the knowledge of how L2 learners learn vowels. The mastering of tenseness, for example, as well as duration, in English vowels becomes an essential key for L2 learners since English vowels are mostly paired with a tense and a non-tense counterpart. Mandarin vowels do not differ in tenseness (Lai, 2005, 2010; Y.-H. Lin, 2007).

2.2.1 Tense and Lax Vowels

Thus, the differences between the perception and the production of tensed and lax vowels are widely discussed. Learners of English in Taiwan or learners whose L1 does not contain a phonemic difference of tense/lax vowels will tend to differentiate tense vowels from their lax counterparts in English (or vice versa) the duration of the vowels (Hung, 2013). However, there is still a high correlation between the perception of

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vowels and the production of vowels (C.-Y. Lin, 2013). This correlation, which may be presented in asymmetrical or symmetrical forms will be part of our focus in studying the performance of the learners in this study.

2.2.2 L1 and L2 Interferences

We found evidence that the means of the F1 and F2 of English vowels produced by Taiwanese EFL speakers and those of American native speakers have been shown are different (Lai, 2005, 2010). Also, Taiwanese EFL speakers are more familiar with the front vowels and perform better on them than on other vowels, where those front vowels existed in their L1 (L.-M. Chen et al., 2006; Flege, 1989b; Flege, Bohn, et al., 1997; C.-Y. Lin, 2013). Flege, Bohn, et al. (1997) believed that the degree of the vowel intimacy between the L1 and the L2 would positively influence the learner’s production and perception of the vowels in the L2. They made an analysis of Mandarin speakers’

English vowel production, which they evaluated by the F0, F1 and F2 values and also one on perception, which was measured by B0, B1 and B3 (Bark) values. They found that [ɪ, æ, ɛ] are the three English vowels most likely to fail to produce by Mandarin EFL learners. However, some others (e.g., Hollich, Jusczyk, & Luce, 2001; Locke, 1980) argued that vowel intimacy may also be a barrier to hinder the learner’s ability to create a new phonetic category and that this problem seems to be somewhat influential.

Chen (2006) was curious about the correlation between one’s perception and one’s production of vowels and if L1 will interfere L2 at this level. Several students majoring in English were chosen to be participants in her study and eleven vowels were included in an experiment of using production and perception tasks by containing test items that were set in an /h__d/ context, which means that all of the target vowels were put into

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that context, and this convention model was first introduced by Fox (1982) and was later adopted by many (e.g., L.-M. Chen et al., 2006; Y. Chen et al., 2001; Flege, 1989b, 1995; Lai, 2005). The results show that it is easier to perceived and to pronounce the front vowels than the mid and back vowels. Also, tense vowels seemed to be less complicated or less unfamiliar for Taiwanese ESL learners than lax vowels, suggesting a language transfer from the L1 to the L2. What is noteworthy here is that for L1 users, back vowels may be steadier; however, some L2 learners, including Taiwanese EFL learners, are less available to perceive or to construct a category for back vowels in L2, which may be a barrier caused by the vowel intimacy.

2.2.3 Vowel Intimacy

The hindrance caused by the vowel intimacy, thereafter, infers a high-density of back vowels, which means that it may be difficult for L1 users to perceive a new category that is nearby when they have already constructed a robust category for some vowels. This view has long been supported by Locke (1980) in that L2 learners might use their L1 grid to apply to their L2 grid. American L2 learners of French, for instance, often fail to pronounce the phoneme [y] and use [i] as a replacement. The field of child language acquisition has shed some insight on this. American infants tend to be more familiar with the word patterns ending with ‘-at’ forms, such as cat, hat, mat, rat, vat, etc., while they might be less familiar with those ending with ‘-up’ forms, as cup or pup.

Word patterns which end with ‘-at’ are therefore seen as high density, and those which end with ‘-up’ are seen as low density. Infants may be less able to pick up (i.e., acquire) new words occurring in a high-density group and may do so more easily with words in a low-density group, for high-density words are more stable to the perception and a

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robust category may have been established for them which it would be difficult to change (Clark, 2016; Hollich et al., 2001). We thus infer that this phenomenon may be carried across to second language acquisition. However, the reason why Taiwan Mandarin speakers tend to perform better on tense vowels may be that they draw a direct analogy from their L1 to L2 but actually fail to construct a real L2 vowel category or have not yet constructed one. Whether this phenomenon is caused by a similarity in the vowel grids or for another reason remains unknown.

Chang (2007) sought to study Mandarin speakers’ and Southern-Min speakers’

vowel perception and production of English. She wondered whether their L1 would interfere with or assist them in their acquisition of the L2. Four vowels, /ei/, /e/, /o/ and /ou/ [sic, [e], [ɛ], [o], [ɔ]] were chosen as be the target phonemes, and were claimed by Chang to be tense and lax vowel pairs. The reason why she chose these four vowels is that in Mandarin all of these four vowels can be matched with one phoneme in L1 in Mandarin, while in Southern-Min, there is a gap between [e] and [ɔ]. Chang utilized contrastive analysis to see whether the differences between L1 and L2 were influential or not. The results showed that there were no significant differences between the Mandarin speakers’ and Southern Min speakers’ perception and production of English vowels. Perception and production do not correlate with each other in the L1 but in the L2. The diphthongs [sic, tense vowels] are more difficult for L2 learners to pronounce than single vowels [sic, lax vowels], which is claimed to be due to the lack of diphthongization.

2.2.4 Influences on the Vowel Space

Lin (2013) sought to investigate the perception and performance of the front

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vowels made by EFL learners in Taiwan as well as the correlation between the perception and production. She focused on two pairs of front vowels, namely, /i/-/ɪ/ and /ɛ/-/æ/. Previous studies, including Fox (1982) and Baker and Trofimovich (2006), had already revealed that the pronunciation of [i]-[ɪ] and [ɛ]-[æ] may be the most difficult problem for most EFL learners. Though Fox (1982) and some others also indicated that learners’ perception of vowels does correlate to their production behavior, Lin (2013), sought to see if the hypothesis would also fit in EFL learners in Taiwan by conducting both perception and production experiments. The participants were twenty sixth-grade students in Taiwan and half of them were female and the others were male. Both experiments included [i]-[ɪ] pair and [ɛ]-[æ] pair words (mono and simple syllable), and the results showed that the [ɛ]-[æ] pair was more difficult than the [i]-[ɪ] pair for the learners in Taiwan in both the perception and production tasks. At the same time, the results also revealed that a significant correlation between the learners’ perception and production did exist.

Issues which are commonly discussed as possible factors influencing the L2 are the background of the participants, the learner’s age of arrival, the length of residence and also the amount of use of L1. While all have been claimed to affect the performance of an L2, the age of arrival and the amount of use of the L1 have a greater influence than the other influences (Baker & Trofimovich, 2006; Flege, 1995; Flege, Frieda, et al., 1997; Flege et al., 1999).

2.2.5 L1 Language Transfer

L.-M. Chen et al. (2007) investigated the production of English vowels by both high and low achieving Taiwan Mandarin English learners. The high achievers and low

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achievers here are respectively college students and elementary school students. These students had all grown up in Taiwan and had received their English education in Taiwan.

L.-M. Chen et al. (2007) indicated that more than fifty percent of the Mandarin speakers in their study showed difficulties in distinguishing English vowels. The error rates for the front vowels in their study are higher than those for the back vowels. They also noted that they did not find any evidence that the amount of use of the L1 made an effect on their participants, and that the low achievers in their study did not show a higher degree of improvement than the high achievers. The inference may be a false interpretation of the theory due to the fact that the exposure to the L1 of both test groups is quite similar. Both of the groups, in fact, shared the same language background, and the age of exposure to English should be counted as the one of exposure to an ESL environment, for many studies have shown the importance of exposure to native adult speakers in establishing a native-like accent.

Lai (2010) found that Taiwanese EFL learners showed a tendency to assimilate English vowels such as [i] and [ɪ] in a merge with the Mandarin vowel [i]. Also, she showed that the higher achievement the learner made, the better the discrimination the learner might have. While learners with a lower achievement might assimilate two vowels from the target language to one vowel in the L1 regardless of the tenseness or other features, high achievers might be able to better assimilate the vowels and to discriminate them from those of the L1.

2.2.6 General Discussion of L2 Acquisition

As discussed above, we can acknowledge that Taiwanese EFL learners often confuse and mispronounce English tense and lax vowels. Lai (2010) was interested in

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the way that learners discriminate English vowels and how they assimilate the L2 vowels to their L1 segments and conducted two perception experiments, including English vowel discrimination and English vowel assimilation experiments. Ninety Taiwanese EFL learners aged from nineteen to twenty-two participated in her study.

The participants were divided into two groups according to their level of achievement in English. The first one was a vowel decision task with minimal pairs, and the second asked the participants to transcribe the sound played in Zhuyin Fuhao (aka the Mandarin Phonetic System) if they felt that the sound they had heard was familiar to any sound in Zhuyin. The results of the perception task showed that the sensitivity of both low-achieving EFL (LEFL) and high achieving (HEFL) toward English vowels share a similar pattern. The discrimination tasks show that HEFL may be more sensitive to tense/lax vowels, while LEFL may not. In assimilation tasks, misperceptions of differences were made, and this phenomenon was thus suspected to be the probable reason why learners may perform mismatched sounds in tense/lax vowels.