Models

國

立 政 治 大 學

‧

N a tio na

l C h engchi U ni ve rs it y

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.

2.3 Models

A number of studies have tried to investigate this phenomenon through different forms of analysis, techniques and frameworks. The three theories of the Contrastive Analysis Hypothesis, the Speech Learning Model or the Perceptual Assimilation Model are the most famous and most commonly applied analytical frameworks for use in perception and production research, and some have been introduced in the former section of this chapter.

Notwithstanding the use of the different models mentioned above, the different stages of progress in language learning and U-Shaped Learning Theory are also widely

‧ 國

立 政 治 大 學

‧

N a tio na

l C h engchi U ni ve rs it y

applied in related research. We may find a growing trend in utilizing error analysis to discuss how language learners may develop their interlanguage to acquire their idealist target language. In this section, we will also give a brief review on how these theories may be applied in studies.

2.3.1 Contrastive Analysis Hypothesis

The Contrastive Analysis Hypothesis compares two languages, which are usually the L1 and L2, and make structural analyses to predict a learner’s potential errors in order to isolate what is important, difficult or easy in second language learning (Gass

& Selinker, 2008). It is widely used to predict the possible output of language learners.

However, it does not deal with the problem of over-production. Lado (1957) first posited the hypothesis, and it was later applied in many studies. Though the Contrastive Analysis Hypothesis has been challenged by many and is notorious for its over-simplicity and lack of explanation in respect to several aspects of psychological and cognitive issues which need to be taken into consideration, it still plays a crucial role in the segmental analysis of the performance and production of an L2.

2.3.2 Speech Learning Model

Flege (1995) created Speech Learning Model which postulated the possible stages of production that language learners might go through. The main purpose of the Speech Learning Model is to construct hypotheses to explain the developments in the production of an L2 by learners of the language. It is composed of four postulates and seven hypotheses which illustrate how language learners process their L2 phoneme inventory based on their L1. The core concept of the Speech Learning Model is that language learning should be seen as dynamic and can be separated into stages. Different

‧ 國

立 政 治 大 學

‧

N a tio na

l C h engchi U ni ve rs it y

stages in the Speech Learning Model composed several hypotheses. The seven hypotheses, labeled one to seven (H1 to H7), normally happen in order, but, in the case of the last few ones, the attainments would depend on the individuals. H1 to H4, for example, proposed that different phones between L1 and L2 may be initially allophonic to L2 learners, and later on, when one can differentiate the phonetic differences and phonemic differences, a new category of vowels would be gradually constructed. For H6 to H7, the representation of the new vowel categories may rely much on the performance in the previous steps as to whether the L2 learners have succeeded in making correct judgements on the classification or not.

2.3.3. Perceptual Assimilation Model

Best (1995), on the other hand, proposed the Perceptual Assimilation Model (PAM), which simulates the perceptual process model that a learner may tend to have to go through when learning a new concept, especially the segmental features in languages. The main purpose of the PAM was to elaborate the speech perception of a non-native speaker. It elaborates a direct realist model of cross-language speech perception and development. It gives hints for us to realize how L2 learners perceive the L2 segments by the similarities to or discrepancies from the segments of their L1.

He raised some assertions such as the following. L2 learners perceive a new sound by assimilating a new sound to one already stored in his/her vowel inventory, dissimilate a new sound from an already stored one and create a new category for it, or do neither for the learners cannot perceive the distinct features of the sound. A number of scholars have then further revised them into different ones at certain level. Below we will review different studies relating to the acquisition or learning of English vowels.

‧ 國

立 政 治 大 學

‧

N a tio na

l C h engchi U ni ve rs it y

2.3.4. Application of the models

Chang (2007), as mentioned before, used Contrastive Analysis Hypothesis in her study and compared all of the possible pairs which appear in the three languages which she included in her account, i.e., Taiwan Mandarin, Southern-Min and English. After a series of comparison and contrasting analyses, she gave recommendations and suggestions as to how the features were transferred from one to another.

Hung (2012) adopted both Flege’s (1995) SLM and Best’s (1995) PAM. She analyzed all of the values retrieved from speakers and cross-examined them with the similar characteristics performed by her participants. She tried to see if the there was any assimilation of each sound and to see if learners dissimilated the different phonemes from each other. Both purposes were done under the SLM and PAM.

2.3.5 More on the Developmental Process

As L2 learners construct their language knowledge, they may experience several processing stages (Brown, 2007; Gass & Selinker, 2008; Lennon, 2008; Zobl, 1984).

Zobl (1984) first proposed a learning progress that learners may undergo on their path to picking up a new language. Many have later revised the theory and created their own model of the learning progress (e.g., Brown, 2007; Gass & Selinker, 2008; White, 1998).

Though not all of the theories applied their practices in studies related to phonetics and phonology, they may still shed light on our study.

Brown (2007) proposed that there may be four different stages of language learning for a language learner: first, a pre-systematic stage, then, an emergent stage, next, a systematic stage, and finally, a post-systematic stage (Brown, 2007; Lennon, 2008; Zobl, 1984). A beginning learner may be unaware of any specific linguistic

‧ 國

立 政 治 大 學

‧

N a tio na

l C h engchi U ni ve rs it y

features of the L2, and they may make random errors in that language. Then, they may start to establish their own rules in this interlanguage, while there may be some errors on the rules they make. Later, those such rules begin to be self-revised by the learners themselves, and the errors will be more consistent and fewer in number. Finally, they may develop a mature system and only sporadic errors may occur within the interlanguage. Repeated errors may still be seen under this stage for ‘fossilization’ could appear in their process of L2 learning.

The U-shape learning theory suggests that L2 learners may seem to produce more occasional errors or mistakes in the middle of their way towards learning the language (Bowerman, 1982; Gass & Selinker, 2008; P. M. Lightbown, 1985). That is, the learners may have overgeneralized some rules about the target language and perform as though going backwards to a stage that may seem to be the same as that of a previous level.

This phenomenon may often appear in the emergent stage and systematic stage (Brown, 2007).

2.3.6 ABX Discrimination Task

Perceptual examination can be assessed by the use of an ABX discrimination test. The model was first introduced by Fujisaki and Kawashima (1970) to see if a listener can differentiate the difference between item A and item B. Listeners have to listen to stimulus A and stimulus B, and, after a while, stimulus X, and they will have to decide whether stimulus X is more like stimulus A or stimulus B. The participants in an ABX discrimination test relies heavily on their short-term memory, for short-term memory has been claimed to play a crucial role in speech perception (Fujisaki &

Kawashima, 1970; Pisoni, 1975). The decision that the listeners make involves a string

‧ 國

立 政 治 大 學

‧

N a tio na

l C h engchi U ni ve rs it y

of reactions implying that the ABX is a result of retrieving one’s phonetic information.

It is also noteworthy that if A and B are the same and listeners will not be informed that the stimuli are identical or not, we can further ask listeners to first identify if A and B are the same phonetic segment. We can see in Figure 2-3 that a listener will have to first identify three stimuli, A, B and X, and then make a comparison among these three. In our study, we will not use such a complicated decision test, but we will inform our participants that A and B will not be identical. The pause between A, B and X may influence the participants’ short-term memory. Therefore, we follow the procedure in Pisoni (1975) in which each stimulus is separated by one second, each set is separated by four seconds, and every set of ten sets is separated by an eight-second pause.

Figure 2-3 is adopted from Pisoni (1975). It represents the process one might go through when undertaking an ABX decision task. The participant has to listen to A, B and then X during the task. If the stimulus is stored in his/her vowel inventory, it will be placed in the phonetic short-term memory, while if it is not, it will be placed in the auditory short-term memory.

Figure 2-3 The perceptual processing when participants undertaking a ABX decision task

‧ 國

立 政 治 大 學

‧

N a tio na

l C h engchi U ni ve rs it y

This figure originally illustrated the use of short term memory, while here we utilize it to explain the operational procedure of our task.