1. Reading Aid for Visually Impaired Veera Raghavendra, Anand Arokia Raj, Alan W Black, Kishore Prahallad, Rajeev Sangal Language Technologies Research Center, International Institute of Information Technology, Hyderabad www.iiit.ac.in

2. Agenda Motivation Challenges Architecture of RAVI Sub Systems What is working and progressing Salient features of RAVI

3. Motivation Visually impaired should be able to access and interact with the computer as a normal person. Visually impaired should be able to access computers in their native language - Indian languages Multi-Lingual screen reader

4. Challenges Tracing the system context information Identifying the active application and extracting the text content Identifying the language or script notation Language processing or script/font conversion Text normalization Invoking the right TTS system Building a high quality TTS system for a language Real-time response of the system

5. WordPadMicrosoft Word Microsoft Excel Microsoft PowerPoint Internet Explorer Language Based TTS Selector Font Converters, Text Normalization Module and LTS Text, Font Name Text Speech Output Text, Font Name Phonetic Notation of Input Text Text to Speech (TTS) Engine Accessibility proxy & Stub System Wide Accessibility Event Tracer Keyboard Event Tracer Microsoft Outlook Architecture of RAVI

6. Sub Systems Text Information Retrieval System wide Application specific Speech Synthesis Font Conversion Text Normalization Letter to Sound (LTS) Rules TTS for Indian and English Language (s)

7. Text Information Retrieval System Information Retrieval Microsoft’s Accessibility Technology is used to retrieve the system information It allows application to expose the type, name, location, and current state of all objects And notifies any Windows event that leads to a user interface change. Application specific Information Retrieval Identifying the Active Application on the desktop Retrieving the Text information from the Active Application Microsoft Active Accessibility (MSAA) Component Object Model / ActiveX Controls Windows Message processing

8. Speech Synthesis Font Conversion True Type Fonts Uses 1-256 ASCII characters to represent characters Character representation is different from one font to other [even in the same language] Separate converter required for each font Proprietary fonts Unicode A universal character set provides a unique number for each character in a language Supports all platforms Supports all the languages..Continued

9. Text Normalization This is a Taj Mahal Welcome to Dr.A.P.J Abdul Kalam Cost of this pen is Rs.50. Monday 14 January 2008, 19:48 GMT I need P3 2.6Ghz, 2GB RAM, 300 GB SATA with 17” LCD screen. Letter to Sound Rules Written form of the word is different from spoken form in some languages like Hindi and Tamil. Eg: /r aa m a/ is spoken as /r aa m/ /aa ch I y aa/ cab be spoken as /aa s I y aa/..continued

10. TTS for Indian and English Language (s) Indian Languages A character in Indian language scripts is close to a syllable a syllable and can be represented as C*VC* where C is a consonant and V is a Vowel Syllable based synthesizer has been built for Indian Languages Collect few thousand of sentences which are phonetically balanced Record those sentences using native and well known speaker of the language Create syllable database from the recorded sentences To reduce the database between 20-40 MB, select the syllable units which are neutral English Microsoft SAPI 5.0 (default for Windows XP)

11. What is working and progressing Working System Information Retrieval Application specific Information Retrieval Font Conversion True Type Fonts UNICODE Text Normalization Letter to Sound Rules Indian Language TTS for Telugu Progressing Indian Language TTS for Hindi, Tamil, and Kannada

12. Salient Features of RAVI Voice guided installation support Automatically starting at system boot up and option to remove start up Character echoing while typing Detailed help documentation for usage and keystrokes combinations This software integrates itself with almost all the variants of Windows operating system This system identifies the language, based on the current context (font name) and automatically switches to the respective speech engine For producing English voice, we have used “Microsoft TTS” system and for Indian Language voices, we have used ‘Indian Language TTS’ system developed at IIIT-Hyderabad This software supports applications like MS Word, Notepad, WordPad, PowerPoint, Outlook and Internet Explorer

13. Thanks

14. Questions?