Abstract:
Sign language is a visual-gestural language mainly used by hearing-impaired people to
communicate with each other. As in oral language, sign language is not universal; it varies
according to the country, or even according to regions. Ethiopian Sign Language (ESL) is the
sign language of the deaf in Ethiopia.
Hearing-impaired people usually face communication problems when they want to
communicate with hearing people without signing skill. At present, sign language interpreters
are used to remove the language barriers between people who are deaf and use sign language
and people who can hear and speak. However, cost, availability and privacy issues make this
an awkward solution at best. A computer application which translates written text into sign
language, would better bridge the communication gap between deaf and hearing worlds.
This thesis was therefore to contribute in this area by developing translator software, which
automatically translates Amharic text into Ethiopian Sign Language (ESL). The developed
translator is referred in this thesis as AmESL-T.
The system is composed of a text-analysis, mapping and sign animation (using 3D avatar)
module. The input for the system is Amharic word, letter and number. The output of the
system is avatar animation of Ethiopian sign language. The signs are represented by means of
VGuido (the eSIGN 3D avatar) animations. For creating gesture animations, eSIGN editor is
used. Amharic has complex morphology which makes complete listing of all words in the
database impossible. Hence, a morphological analyzer that reduces morphological variants of a
word into a common form is developed and integrated to AmESL-T.
AmESL-T is constructed as a web application to allow usage to large population. Using the
translator, it is possible to translate Amharic texts into gestures that a hearing impaired can
understand. The tool is useful in enabling people who don’t know sign language to communicate with deaf individuals. The hearing-impaired can also utilize the software to
develop written language skills. Moreover, it may be used as a teaching tool for Ethiopian sign
language.
AmESL-T was evaluated in terms of quality of signing and subjective opinions. Quality of
signing was measured based on intelligibility and acceptability of signs. The evaluation results
showed that the quality of signing and the translation accuracy are acceptable, and it satisfies
users' need. For better translation results, further research areas are also pointed out.