2004 Conference Proceedings

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Supavadee Aramvith
Chulalongkorn University
Department of Electrical Engineering, Faculty of Engineering,
Chulalongkorn University, Pathumwan
Bangkok, Thailand
Email: supavadee.a@chula.ac.th

Teeranoot Chauksuvanit
Chulalongkorn University
Department of Thai Language, Faculty of Arts,
Chulalongkorn University, Pathumwan
Bangkok, Thailand
Email: teeranoot.c@chula.ac.th

1. Introduction

Communication is the important means that people in a society use in their correspondence to convey or exchange messages, news and information, thoughts and feelings. Rapid advances in information and communication technologies (ICTs) are central to transformations in the way people conduct in their everyday lives. Information and knowledge are expanding in quantity and accessibility. However, people with functional limitations, such as deaf people, often experience wide communication gaps even though most of them have normal intellectual capacity. Due to the hearing limitation, deaf people have developed their own culture and methods for communicating among them as well as with hearing groups by rely on signing.

In Thailand, Thai Sign Language (TSL) is used by deaf Thais. It is unique to Thailand as is spoken Thai. Deaf children learn signing only through interaction with other deaf people in their community or through school for the deaf. Learning from these two sources can cause confusions to deaf children as the sign language taught and originated by hearing teachers is technically different from their native mother language, "the Thai Sign Language of the Deaf Thai culture." Moreover, there are two methods of teaching communication to deaf children; teach sign language as the first language and the language of the majority hearing culture, that is, reading and writing, as the second; another approach is a bi-lingual one. Without good role models for learning sign language and without equal access to the full curricular content of education, these children represent an enormous waste of Thailand human resources as of today. Thailand represents one of the most progressive developing countries of the Asia-Pacific region in programs and opportunities for deaf children. The Royal Thai Government presently issues National Developmental Quality of Life of Person with Disabilities plan (year 2002-2008); part of it is to provide policies and directions to support the educational rights of deaf Thais [1]. An active organization for deaf Thais is the National Association of the Deaf in Thailand (NADT), formed in 1983. One of their outstanding activities is the research in TSL to compile signs in TSL from all the deaf groups in Thailand and collated them into groups in accordance with linguistic principles. As a result, "the Thai Sign Language Dictionary, Book One"[2] was published in 1986. It was approved for use within the existing school system. Prior to that, Sethsatian school for the deaf has published "Signing Exact Thai & English Book one"[3] in 1979, as a tool in teaching sign language using total communication approach. In this paper, we present the structure of Thai Sign Language in section 2. We provide some insights of the development of TSL dictionaries and the directions in developing electronics TSL dictionary in section 3. Conclusion is provided in section 4.

2. Structure of Thai Sign Language (TSL)

Sign languages can be considered as "gestural communications," which have been internationally accepted as languages among spoken languages. These special languages of deaf people are established as fully expressive languages which not only exhibit complex organizational properties, but also display grammatical devices not derived from spoken languages. The distinct national sign language of indigenous deaf populations should be officially recognized as their natural language of right for direct communication [2].

Native Thai Sign language used by deaf Thais has a very long history of its establishment, as well as the spoken Thai language, which has been developed over 700 years ago. Modern TSL, like all languages, has evolved, borrowed, and adapted features from both external and internal influences. TSL is a language as unique to Thailand as is spoken Thai. It is also distinct and different from the spoken Thai language in both grammar and in syntax. These distinctions reflect the cultural textures of deaf Thais and their communities that use TSL as a communication medium and cultural transfer from one generation to the next one. Signing in TSL system can be differentiated into 5 categories as follows:

1. Pantomimic signs are the signing of hand-shape, hand orientations, and hand movements simultaneously to convey meanings of that signing.

2. Imitative signs are similar to Pantomimic signs. However, by using the imitative signs, the signers intend to convey particular meanings instead of the overall meanings. For example, the signer pronounces the signing of hand holding steering wheel of the car to convey the meaning of both "car" and "car driving."

3. Metonymic signs are similar to Imitative signs but how the sign was presented is the result of reference. For example, the sign of saluting refers to "soldier."

4. Indicative signs are represented by point the finger to the reference object in which that object does not need its presence at that moment of signing. For example, to represent themselves, the signers just simply point their index finger toward their chest.

5. Initialized signs are done by initialize hand-shape corresponding to the first letter of the word in a spoken/written language. It is invented in such a way for deaf people to remind the listeners of a word in a spoken/written language.

Like any other language, a sign language will have a large number of signs which are nearly synonyms, i.e., have similar meanings. The slight distinctions in the meanings are part of the richness of the language, permitting sign languages to be very precise and make fine distinctions, just as in spoken language. The structure of fluent sign languages is very efficient. Hand-shape, location, motion, orientation, and the broad category of non-manuals and facials-occur simultaneously are all integrated and represent meanings in the ways easiest for the hands, the eyes and the mind. Each sign is not isolated, but uses parts common to many other signs. The principle of verb directionality will save much time and effort in signing. Some verbs in sign language can move in different directions to show who is the actor and who is the receiver. Other verbs or adjectives or nouns can be signed at different locations to show which person or thing is referred to. This is one of the most important ways in which sign language is efficient with time and efforts, since what is happening and who or what is acting or acted upon can be signed at the same time, rather than separated by long pauses. The principle of simultaneous grammar on the face is most important. For negation, the form using a small headshake is the most common and important. Repeating a movement or not, using a larger or smaller movement, and changing the speed or rhythm of movement in various ways can be performed very rapidly on the hands, and corresponds in some spoken language to a longer phrase often using many extra words. Even the difference between a verb and a noun related in meaning is sometimes shown this way. To create a new sign, it can be done by changing the formation of a sign defined earlier. Such changes are according to the rule used in defining new spoken words. Yet there are two limitations regarding the evolution of sign language: the physical and language limitations [4] It was also suggested from the research work of Warinthorn [5] that some parts of TSL is borrowed and adapted from American Sign Language (ASL). The issue of noun and verb related to the formation of signs in TSL needs to be investigated in order to realize the nature of TSL, the correct understanding of the study of TSL. This indeed will lead to the effective communication system for within the group of deaf people and with normal people. This could be achieved by creating such tools to develop TSL communication system such as dictionary, database, and various electronic media.

3. Thai Sign Language Dictionary: Approaches and Directions

Although Thailand has provided educational supports to deaf Thais since 1950s, as of today the place of deaf Thais in the society is still limited. Part of the reasons is that they lack the tools help in their communication such as dictionary. Its development is not in pace with the rapid advances in communication technology. In Thailand, the compilation of TSL dictionary is divided into 3 periods as follows: 1. Early phase. In the early phase, there is no systematic approach in compiling signs in TSL since Thai signs used have been imitated and influenced from American Sign Language to use in school for deaf. 2. 2nd phase. In the second phase, the study of signing in TSL started to be more systematic as the deaf teacher is well-educated. The person who played an important role in developing TSL dictionary is Nirun Santitrakul, a deaf teacher at Sethasatian school of deaf. A dictionary titled "Signing Exact Thai & English Book one" was released in 1979. It consists of 3,000 Thai words, 1,860 English words, 2,000 illustrations, and notation together with explanations in Thai and English. The dictionary is an important teaching tool based on total communication approach which is the method to practice deaf students to listen by ear, to talk by mouth, and to perform lip reading and study TSL as a structured sign language with a particular finger spelling, as hearing people do. Yet, it is the system that teaches the deaf to understand the language of hearing people, not for the hearing people to understand TSL. 3. 3rd phase. In the third phase, the development of TSL dictionary is based on sign language. In 1980, Charles Reilly and Manfa Suwanarat proposed the project for compilation of the TSL by handshapes, using the notation system designed by [6]. The result was "The Thai Sign Language: A Model Dictionary by Handshapes" which became a model for the later issue of the "Thai Sign Language Dictionary, Book One" in 1986. NADT has released the second, Revised and Expanded, edition of the TSL dictionary in 1990. This demonstrated how possible it would be for deaf people in Thailand to direct research efforts into their own sign language, and document their own sign languages instead of replacing theirs with sign languages from developed countries. The dictionary was the pride of deaf people and their friends in Thailand. In this dictionary, the information for over 3,000 signs in TSL are shown. The dictionary is organized so that related signs are together, i.e., those which have the same sign or handshape "root". The signs are grouped into 5 broad groups and 3 small groups. The extra features of this dictionary include the index in Thai and in English, the grouping methods of signs, aided the understanding and the studying of TSL.

From analysis of the history and features of TSL dictionary, we propose a development of an online electronics TSL dictionary which will be based on signing in TSL as well as the uses of hand locations, handshapes, and the hand movement as the TSL that deaf Thais commonly used in communication. The dictionary will also include finger spelling system which becomes a standard of TSL such that it can support more TSL vocabularies for deaf Thais to communicate more efficient and effective. The dictionary system will employ sign language recognition, developed based on vision-based gesture recognition technology [7], to provide users additional method in query the database. The users will be able to interact with the system not only through using keyboard but also through signing in front of the camera connecting to the system. We also propose a method for optimizing the database of signing videos by employing a new method of video coding. The method enhances video quality and reduces the size of the signing videos.

4. Conclusions

In this paper, we described the structure and current state of Thai Sign Language (TSL) which is a language used by deaf Thais. The needs and developments of TSL dictionary were reviewed. Finally, we proposed a development of an online electronics Thai Sign Language dictionary which will employ the state-of-the-art technologies such as vision-based recognition and video synthesis. We believe the development of TSL database is such an important task to make a standardized TSL educational system which serves as an information source and aids effective communication among deaf Thais and among deaf Thais and hearing people.


[1] Ministry of Social Development and Human Security, National Developmental Quality of Life of Person with Disabilities plan (year 2002-2008), Royal Thai Government, 2002.

[2] The National Association of the Deaf in Thailand, The Thai Sign Language Dictionary, Revised and Expanded Edition, Thai Watana Panich Press co.,Ltd. Bangkok, Thailand, 1990.

[3] Niran Santitrakool, Signing Exact Thai & English. Book one, 1979.

[4] Woll, B. & kyle, J.G., Sign Language, In Asher, 1944.

[5] Warintorn Jaruchottanawat, "A Study of Noun and Verb Pairs in Thai Sign Language," Master's Thesis, Graduate School Chulalongkorn University, 1979.

[6] Stokoe, William C., A Dictionary of American Sign Language on Linguistic principles, Silcer Spring MD, Lintok Press, 1965.

[7] Ying Wu & Thomas S. Huang. "Vision-based Gesture Recognition: A Review," A. Braffort et al. (Ed.) Lecture Notes in Artificial Intelligence 1739, Gesture-Based Communication in Human-Computer Interaction, 1999

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