DESIGN
AND IMPLEMENTATION OF SYSTEM TO ENHANCE ACCESSIBILITY INFORMATION FOR VISUAL
IMPAIRED PEOPLE
L.A.M.P
Nimalaratne1, A.P
Madurapperuma1, K.A.R.D Gunaratne1
1 The Open University of Sri Lanka,
Faulty Of Engineering Technology, Department of Computer Engineering
INTRODUCTION
Technology can be used to enhance the life of people
with physical impairments. There are a considerable number of people who are
either visually impaired or totally blind (There 285 million people are visually impaired worldwide:
39 million are blind and 246 have low vision) [5]. Also this software can be used by those who cannot read, but have
the ability to understand the Sinhala language (Other Communities).Such people
find it difficult to benefit from the information sources widely available on
the Internet. Western countries and other more technologically advanced
countries have tried to remedy this situation by building screen readers that
would read out a selected piece of text. However, there are no such systems
capable of converting text written in Sinhalese language to voice. This project
is an attempt to build an open source text-to-speech (TTS) system that will be
widely available, platform independent and easy to use. The solution will be
implemented as a browser plug-in making it usable by anybody who has access to
a browser.
BACKGROUND
The conversion of text to speech, i.e.
the process of automatic generation of speech output from computer readable
text, is called speech synthesis. TTS systems have been developed for many
languages, with majority of them working with the English language [2]. Sinhalese
is a language used by a very limited population of the world. There are only a
few attempts that tried building TTS systems especially for Sinhalese language [1].Those
that are implemented function as stand-alone applications that require the user
to follow a complex installation procedure. In contrast, this is the first known
documented work on a Web Based Sinhala TTS Application that has been developed
as a plug-in for the Mozilla Firefox Internet browser. This application uses
Festival Framework Based Sinhala TTS System [1][2][3] .The
Festival Speech Synthesis System is an open source, stable and portable multilingual
speech synthesis framework developed at the Center for Speech Technology
Research (CSTR) of the University of Edinburgh [3]. This framework is
considered the most suitable for Sinhala language by the local research community
involved in language processing [2].
METHODOLOGY
Figure 1 :Overall concept view of the system .
Diagram in
Figure 1 shows the overall system. The user selects the text to listen to from
the browser (01) and activates the extension (02).The extension converts the
selected text to speech and plays the output on the computers speakers or other
sound producing device (03).The core of the system consists of Sinhala TTS
engine which will be used to generate speech synthesis for Sinhala, it takes phones
dictionary from linguistic analyzer and normalised Sinhala Unicode text from
text analysis as input and match the letter to sound rules and letter to phone
prediction which results
in desired phone sequences. Then using the Unit Selection Algorithm, appropriate
sound segments for the phone sequences are generated with the help of Speech
Database. Finally the Waveform Synthesis mechanism outputs the sound relevant
to the wordings.
DESCRIPTION OF
TECHNOLOGIES USED
We describe implementation and evaluation of the
Sinhala TTS browser extension based on festival framework. We have used two
core components of the Java Speech API, i.e., speech recognition and speech
synthesis [3] as the foundation. We found that the Java platform to be the best
option to design a speech application given its portability, platform
independence and support provided by all major web browsers. Other technologies
used in this project include Live Connect [4], Speech Synthesizer [1][3],
Chrome [4], and XPCOM (Cross Platform Component Object module) [4].The Chrome
Component located in the Browser extension is able to add features to the
Browser and XUL files these are contained in the Chrome Component and helps to design
extension’s user interface. The XUL file in with the XUL file in the browser,
hence the extension adds additional functionalities to the browser. XPCOM is a
framework that allows different pieces of the software that are to be
developed independently. It helps integrate JavaScript and the Java component
of the software. LiveConnect is a feature of Web browsers that allows
Java and JavaScript software to intercommunicate within a Web page. From the
Java side it allows an applet to invoke the embedded scripts of a page or to
access the built-in JavaScript environment. Conversely, from the JavaScript
side, it allows a script to invoke applet methods, or to access the Java
runtime libraries [4].
DISCUSSION
AND FUTURE WORK
This system is a bowser plug-in that
can be installed on any browser supporting Java language. This system is attached
to the browser as a plug-in and is currently used with the mouse interface.
Currently the application is implemented in Firefox. This application can be
extend as a another browser application such as mobile browser (Opera mini,
Android Browser, Dolphin Browser like that).Also the project can be
carried further by generalizing the tool so that the application will be able
to function on voice commands thus maximizing the user’s interaction with the
computer.
REFERENCES
1. Prof Dias,Dr.Jayasena. (2010). Computer text to Speech System with pharse
breaking Algorithm(AMoRA). University of Moratuwa,Department
of Computer Science and Engineering,
2. Ruwan Weerasinghe,Asanka wasala,Viraj
Welgama,Kumudu Gamage. (2007). Festival-si:A
Sinhala Text to Speech System. IEEE Language Technology
reasearch Labotratory University of Colombo,School of Computing
3. Pawl Taylor,Alan W Black,Richard Caley
(1987) The Architecture of the Festival
Speech Synthesis System,University Of Edinburgh Center for Speech Tecnology
Reasearch.
4. Mozilla Development Network and
Individual Contributors(MDN)(2005-2013)
