The Effect of Using of TBLT on Vocabulary Learning by Deaf or Hard of Hearing Learners

The aim of the present study was to investigate the effect of Task-Based Language Teaching (TBLT) on the learning of new lexical items by Deaf and Hard of Hearing (DHH) learners. For this purpose, 30 beginner learners, studying English in the first grade of high school in two exceptional learners’ education centers in Yazd, Iran were selected. They were divided into two groups: experimental and control groups. The experimental group received Task Based Language Teaching (TBLT) treatment within which new lexical items were taught through different techniques based on form-focused task design. In the control group, the learners were learning the vocabulary items through the traditional method of Grammar Translation Method (GTM). Firstly a pre-test based on pictures was given to DHH learners. After 9 sessions of treatment, each lasted 30 minutes, a post-test was given to learners. T-test was used to analyze the data collected. The results showed that there was a significant difference between experimental and control groups. From different perspectives, the implication of this study can be discussed. This study can open an opportunity for teachers of DHH learners to experience some teaching methods not usually used in exceptional educational curriculum. Furthermore, these methods may be of high potentials for exceptional learners.


Spencer, 2001).
During teaching a foreign language to DHH learners in lower level grades of school, it is necessary to focus on the teaching of the new lexical items of that foreign language. (Paul, 1998) The main and important point is that many of DHH learners don't have the same amount of knowledge of vocabulary as their hearing peers. Learners who are DHH have limited range of vocabulary and they use vocabulary inappropriately while they speak and write. Besides they use shorter, simpler and less precise sentences (Paul, 1996(Paul, , 1998Schirmer, 1985).
These learners face with many problems in acquiring a native or a foreign language because their knowledge of lexical items quantitatively is less than that of normal hearing peers and because they have smaller lexical repertoire, they usually encounter many problems in making new sentences (Luckner & Cooke, 2010). The hearing impairment learners are reported to use phrases like "the window in front of the car" or "the step by the street" instead of "windshield" or "curb" (Barker, 2003).
It is necessary to realize that teaching a foreign language to Deaf learners require careful preparation of the teacher. During teaching a foreign language to Deaf learners, especially in low level learners, the focus should be mainly on vocabulary of foreign language. Also teachers should be aware of the difference between the degrees of hearing loss. Usually it is not appropriate to give the translation of new words in the first language; it does not guarantee the success of learning. Also the variety of degrees of deafness affect the teaching of a foreign language to DHH learners. Deaf children are visual learners (Luckner & Cooke, 2010). As such, they may particularly benefit from using visual strategies (Easterbrooks, 2010;Schirmer, 2000). Thus his study attempted to investigate the role of TBLT in learning new lexical items to DHH junior high school learners in Yazd in Iran.

Review of Related Literature
There are some methods for teaching vocabulary to normal students (Heidari & Arāghi, 2015;Shoari & Davatgar, 2015;Taheri, 2014;Touti, 2013) but unfortunately as it was mentioned, it seems that there is no research addressing English vocabulary development for DHH learners in Iran.
Among different approaches offered for language education, although TBLT has not yet been sufficiently researched or proven empirically in terms of its classroom practice in school foreign language learning contexts (Carless, 2001), Shintani (2012) believes that TBLT can be applicable for beginners if the input-based-tasks used for them. These kinds of researches were done in normal language learners; however, the current study takes initiative to examine the effect of TBLT on learning new lexical items to DHH learners.
There is no specific definition for TBLT, but many writers agree that this approach has three main principles: the first one is that it is a learner-centered approach (Ellis, 2003;Nunan, 2004;Richards & Rodgers, 2001); it has some components like goals and procedures (Murphy, 1996;Nunan, 2004;Skehan, 2003) and it supports content-based and meaning-based tasks (Carless, 2002;Littlewood, www.scholink.org/ojs/index.php/sll Studies in Linguistics and Literature Vol. 2, No. 2, 2018 Published by SCHOLINK INC.

2007).
Long and Robinson (1998, p. 15) defines TBLT "as a pedagogy which uses pedagogical tasks to draw learners' attention to particular aspects of the language code". Based on this definition we can imply that pedagogy does not include only one task, but a sequence of tasks and these tasks focus on specific language features. By language feature it is not limited only to grammar, but also it extends to cover vocabulary, expressions and language functions.
TBLT proposes the use of tasks as a main component in language classroom because it provides better context for learners to activate their acquisition process and promote L2 learning (Shehadeh, 2005).
TBLT, therefore, is based on a theory of language learning rather than a theory of language (Richard & Rodgers, 2001). One of the characteristics of TBLT is Focus on Form (FonF). Focus-on-form instruction can subsume planned focus-on-form and incidental focus-on-form. Ellis, Basturkmen and Leowen (2001) explain that the former as a kind of instruction which involves the use of focused tasks.
Like the same-or-different task could also be used to present pairs of pictures where the learners are required to use "on" and "in" (the target forms) so as to determine whether the pictures are the same or different. Shintani (2013) investigated the effects of two instructional approaches, Focus on Forms (as present-practice-produce) and Focus on Form (as task-based teaching) on the acquisition of new words (nouns and adjectives) by young Japanese learners. He found that both types of instruction were effective for the acquisition of nouns on the part of young beginner learners, so "task-based teaching" is more effective in comprehension-based tasks rather than production-tasks. There are several reasons for examining the effectiveness of using TBLT in acquiring new English lexical items by DHH learners.
The most important one is that many studies have been using TBLT for teaching English as a foreign In line with the educational purpose of the present study and to shed light on the plausibility of the TBLT, the researcher has made an effort to use different types of tasks to teach new lexical items to DHH learners. As less hearing able people are more vision-oriented people, TBLT may work for them better.

Research Questions
Concerning the special subjects of the study and with respect to the application of TBLT approach in their contexts, the following questions have been addressed in this study: 1). What is the difference between the effects of applying TBLT versus traditional method (GTM) to teach vocabulary to DHH learners?
2). Does the DHH learners' gender have any moderating effect on the main effect of the study?

Methodology
The current study was conducted to examine the effect of TBLT in learning new lexical items by DHH learners in two exceptional schools in Yazd. A quasi-experimental design was selected. For the population available to the researcher of the study, a pre-test, post-test design was selected.

Participants
The DHH learners in Iran have two educational options. They can either attend exceptional schools or go to ordinary state schools with their hearing peers. In the present study from the two exceptional junior high schools in Yazd, Iran, 30 DHH learners were selected (18 girls and 12 boys). They aged from 14 to 18 years old and their degree of deafness is from mild (24-45 dB) to profound (>90 dB).
One of the groups was chosen as the control group with 12 members (7 females and 5 males) and the other one as experimental group with 18 members (11 females and 7 males) Their English language proficiency is at beginning level.

Instruments
In order to examine the research hypotheses of the study, two sets of test (pre-test and immediate post-test) were designed and developed by the researchers. The Cronbach's Alpha of the both tests which show the relatively high degree of internal consistency, i.e., reliability of the test, are in turn .78 and .82. The tests were also reviewed by two professional English teachers for practical purposes. The focus of the tests was on receptive vocabulary knowledge through pictures, as many of the DHH learners are vision-oriented and they can answer these kinds of tests more easily than the normal tests.
The immediate post-test was the parallel form of the pre-test consisting of multiple-choice tests containing 45 items. Each item on pre-test and post-test consisted of a sentence followed by four pictures.
In this study, the researcher in the eleventh session gave the DHH learners a pre-test form A at the beginning of the session and after thirty minutes; she gave them the second form (B). Because these www.scholink.org/ojs/index.php/sll Studies in Linguistics and Literature Vol. 2, No. 2, 2018 learners seemed bored to answer all of the questions once, so the researcher decided to give the test in A and B forms. The participants in both the experimental and control groups were tested on these two forms in pre-test and post-test ( 25 items in form A and 20 items in form B).

Procedure
As mentioned earlier, the present study aimed to examine the effectiveness of using TBLT in learning new lexical items by DHH learners in the first grade of junior high school through employing the following procedures: When the English classes started at the beginning of the academic year, one of the researchers attended ten sessions as an observer in both the control and experimental groups. The researcher wanted to become familiar with the context and the participants of this study. These observations helped the researchers to collect data in better ways.
After administering pre-test, the researcher started the treatment of the study for teaching new English lexical items. Different tasks were designed for the treatment including "picture cued task, finding the picture task, same or different pictures and word mapping task". These kinds of focused tasks (Ellis, 2001) could be appropriate for DHH learners who are vision-oriented learners. In the pictorial cued task, some sentences with missing words were written on the board. Then the researcher listed some pictures and helped the participants to write the missing words in the incomplete sentences by writing the name of the pictures. For example, there were pictures of a table, a chair and a bedroom. Then the participants of the study were asked to fill the gaps in the sentence like the following one by the corresponding names of the pictures: There are ... and a … in my … In the same or different picture task, for example, the researcher listed a set of pictures on the board and helped the participants to divide them into two columns, for example, objects and animals. Usually one of the words in this task was an extra one to check the participants' careful attention. Following the completion of all the activities, the post-test parallel to the pre-test was administered on session 10. In the control group the researcher used the traditional way of the teaching the new vocabulary. By translating the words and writing the Persian equivalents of the English words she tried to help the participants to make sense what the words meant.

Data Analysis
Considering the research questions, the researchers tried to measure the effectiveness of the treatment on the participants with respect to data collected between the experimental and the control groups.
They also tried to measure the effect of the gender as the moderating factor of the study on the main variable of the study which is the use of TBLT in teaching of the vocabulary to the DHH learners. The data were analyzed using an independent samples t-test. The scores were fed into the SPSS software to compare the results of the study taken from experimental and control groups across gender.

Results
After examining the participants' answers to questions, a total score was given to each subject. An independent sample t-test was conducted to compare the mean scores of pre-test for the two groups; experimental and control. Table 1 presents the descriptive statistics about the mean and Standard Deviation in the two groups.  The second independent sample t-test was conducted, after nine session of treatment in the experimental group, to compare both groups' mean scores of pre-test and post-test in applying TBLT for teaching new lexical items to DHH learners in the two groups.  The second independent samples t-test indicated that there was a statistically significant difference (t (28) = 3.29, p = 0.003< 0.05 (two-tailed)) between the two groups. An examination of the data in the post-test indicated that there was no violation of the normality assumption (the significant level of Leven's test is less than 0.05 p = 0.04). The magnitude of the differences in means (mean difference = 4.58) was large (eta squared = 0.27) ( Table 4).

Table 4. Independent Samples T-Test for Pre-Test and Post-Test between Groups
Leven's Test for As gender was hunched to act as a moderating factor, the descriptive statistics for the difference in the vocabulary learning between genders in the two groups in post-test reported in Table 5. As it is observed in Table 6, there was not a statistically significant difference in the experimental group (t (16) = -1.60, p = 0.12> 0.05 (two-tailed)) and in the control group (t (10) = -1.23, p = 0.24> 0.05 (two-tailed)).

Discussion and Conclusion
The present study aimed to investigate the effect of using Task applicable and more appropriate in DHH learners' educational system.
As it was mentioned earlier, there are some researches which have been done in teaching new vocabularies to Hearing elementary learners (Taheri, 2014;Touti, 2013). However, to the best of the researcher's knowledge, no TBLT approach has been deployed to teach vocabulary to DHH learners in Iran. So the researcher applied TBLT as an efficient approach to teach new English vocabularies to DHH learners.
Many researchers have applied TBLT in their classes to show its effectiveness on lexical acquisition with hearing low level learners (Javanbakht, 2011;Leaver & Willis, 2004;Shinatti, 2011;Taheri, 2014; Willis & Willis, 2007; Zahedi & Abdi, 2012) but it seems that there are little researches were done to show the effectiveness of new methods and approaches with DHH learners.
In one comparable research to this study, Yaghoubi, Atarodi, and Khalili (2013) investigated the relationship between multimedia learning and lexical learning among DHH learners in the first grade of junior high school in Qom. Using multimedia significantly increases the ability of DHH learners to learn and understand the written words. The similarity between the study and the present study is that there was a significant difference between groups of participants after using semantic mapping in teaching new lexical items in pre-test and immediate post-test.
In one study, Ju (2009) studied the improvement of reading comprehension and English vocabulary learning by DHH learners. To overcome the difficulty of reading for these learners, the researchers used a kind of multimedia program, graphic organizer and key words. The results of post-test showed a significant difference compared to the pre-test in learning new words. Also, the learners found that the stories in multimedia form helped them to learn better.
In another research, the effectiveness of using pictorial representation of new words was detected by Paatsch et. al., (2006). Learners demonstrated significant improvement after vocabulary training. There is a similarity between this study in using pictorial cues and their studies.
It seems that in one comparable research on retention and retrieval of new lexical items by DHH learners, Barker (2003) taught 218 new lexical items to a group of DHH learners. After four weeks, he found that DHH learners retained more than half of the new words when retested 4 weeks after intervention. The difference between this study and Barker's study was the number of items, the intervention time and having control group but the similarity of both studies reveals the effectiveness of using a new approach for teaching new lexical items in retention of those new words by DHH learners.
As a matter of fact, DHH learners have special needs. Their needs should be fulfilled by educational system of country. Among the wide varieties of their needs, they need to learn a foreign language. The old traditional method being used in their contexts cannot be responsive to their conditions and requirements. Unlike traditional teacher-centered classroom where the teacher is the dominant figure, in TBLT the learners are at the center of the learning process: they are expected to assume a high degree of responsibility for their own learning through effective self-learning, working with others, and demonstrating an ability of their learning achievements.
Their headmasters should be well aware of the opportunities available for them. They should acknowledge that the new approaches of language education can be modified so as to meet the demands of the learners with special needs, particularly those who suffer from hearing deficiency.
As the results of the present study show, TBLT can be a more efficient approach in comparison to the old traditional ones. By designing some interesting and motivating tasks, the language practitioners can increase the efficiency of foreign language instruction to DHH learners. As they are vision-oriented people, they need different tasks accompanied by pictures, maps, games, graphs, role-playing and body-gestures activities. Such activities help to visualize the concepts and make sense in what they are teaching.
In this way, the language teachers can compensate the DHH learners' impairment in their hearing sense.
The researcher's observations of different classes in the exceptional centers clearly show that the extent to which the learners were looking forward to welcoming her to attend their English classes and present the different tasks to learn English. The results of the study and the researchers' personal experiences in working with DHH learners indicate that they are enthusiastic to learn a new language but they need innovative learning materials in term of designing new demanding tasks, which can engage their different senses by virtue of the fact that they have lost partially or totally their hearing senses.
Some people think that students with hearing impairment are unable to learn English. From the results of this study, it can be seen that even though DHH learners are not able to master English lexical items by using TBLT in comparison to their normal peers, but the teachers of these learners by using new and current methods can help them to learn much more compared to the traditional ones. It is important to note that this study is small in scope, and therefore the implication must be viewed with caution.
This research will give new viewpoints about students with hearing impairment and give strong motivation for the researcher to teach, not only in teaching normal students but also students with disabilities, especially students with hearing impairment. Also language practitioners in the field of Deaf and Hard of Hearing education should be more aware about the current methods of teaching in the field of ELT and use these kinds of methods and approaches as TBLT for educating DHH learners.
It is expected that the information can be useful for the readers and will give information about learners with hearing impairment that they have the same right in education just like other normal learners. The school should provide various materials to teach DHH learners such as flashcards, videos, wall charts and more reference books based on the needs of those learners. Also, they should recruit teachers who are specialized in the field of ELT, so as to can improve the quality of teaching and learning process.
Also the teachers should apply various teaching methods and approaches to improve DHH learners' mastery of English. They can use flashcards which contain picture following the written words; those learners are more attracted to visual things since their hearing disturbed. Teachers should not only rely on textbooks, but they should also search for more interesting materials in internet. Another suggestion www.scholink.org/ojs/index.php/sll would be directed to syllabus designers and material developers. It seems that DHH learners are very much in need of course books and materials based on their needs.
There are several sources of limitations regarding the methodology of this study. A key weakness of this study is the limited number of participants in this study. This investigation included only 30 DHH learners. So the generalizability of the findings to all DHH learners should be made with caution. Also, a true experimental design could not be used. A true experimental design requires that the participants be assigned randomly to the control and experimental groups.
In the current study, TBLT was used in the experimental group to test its efficiency to teach vocabulary.
Further researches should be done to use TBLT to teach other language skills to DHH learners.
Longitudinal research would be of particular benefit. The current findings are open for confirmation by further research. The researchers recommend their fellow researchers to be daring enough to test other approaches and bring change to DHH learners' centers. Also the prospective researchers are recommended to deploy more efficient techniques to set more well-documented results.
Generally, it seems that introducing new lexical items to DHH learners is not easy, even in their native language. Therefore, an appropriate approach or method is needed to overcome the problem of learning vocabulary by DHH learners. The chosen approach should consider DHH learners' limitations. It can be concluded from the results of this study that learning new lexical items through using different tasks results in better learning of vocabularies.