2. CONTENTS
 Introduction
 History
 Usage
 Sample Program
 VoiceXML Inputs
 Goals of VoiceXML
 Advantages of VoiceXML
 Conclusion

3. Introduction
 VoiceXML (VXML) is the W3C's
standard XML format for specifying interactive
voice dialogues between a human and a
computer.
 It allows voice applications to be developed and
deployed in an analogous way to HTML for
visual applications.
 Just as HTML documents are interpreted by a
visual web browser, VoiceXML documents are
interpreted by a voice browser.

4. VoiceXml HTML

5. ACHITECTURE

6. Welcome
to voice
portal
query
 A common architecture is to deploy banks of
voice browsers attached to the Public
Switched Telephone Network (PSTN) to
allow users to interact with voice applications
over the telephone.

7. History
 AT&T,IBM, Lucent, and Motorola formed
the VoiceXML Forum in March 1999, in
order to develop a standard markup
language for specifying voice dialogs.
 In March 2000 they published
VoiceXML 1.0
 The W3C produced version of VoiceXML
2.0, which reached the final
recommendation stage in March 2004.

8. Usage
 Many commercial VoiceXML
applications have been deployed,
processing millions of telephone calls
per day.
 These applications include:
order inquiry, package tracking, driving
directions, emergency notification, flight
tracking, voice access to email, audio
news magazines, voice dialing etc.

9. Sample program
VoiceXML has tags that instruct the voice browser to
provide speech synthesis, automatic speech recognition, dialog
management, and audio playback.
The following is an example of a VoiceXML document:
<vxml version="2.0"
xmlns="http://www.w3.org/2001/vxml">
 <form>
 <block>
 <prompt> Hello world! </prompt>
 </block>
 </form>
 </vxml>

10. When interpreted by a VoiceXML
interpreter this will output "Hello world"
with synthesized speech.
 Typically, HTTP is used as the transport
protocol for fetching VoiceXML pages.
Some applications may use static
VoiceXML pages, while others rely on
dynamic VoiceXML page generation using
an application server like tomcat, web
logic.

11. Sample program:
<?xml version="1.0" encoding="UTF-8"?>
<vxml version="2.1"> <form id="MainMenu">
<field name="instrument">
<prompt>What is your favorite musical
instrument?</prompt>
<grammar > [guitar mandolin dobro (violin fiddle) banjo]
</grammar>
<noinput> Did you say something? I didn't hear you.
<reprompt />
</noinput>
<nomatch> I suppose that's OK, but it's not on my top five.
Want to try again?
<reprompt />
</nomatch>
</field>

12. <filled namelist="instrument">
<if cond="instrument == 'guitar'">
<prompt>That's right! Hang up and go practice.</prompt>
<elseif cond="instrument == 'mandolin'" />
<prompt>Nice... and only four strings to keep in tune.</prompt>
<elseif cond="instrument == 'dobro'" />
<prompt>Boy, that's no fun to learn, is it?</prompt>
<elseif cond="instrument == 'violin'" />
<prompt>We call that a fiddle, Mr. Fancy Pants.</prompt>
<elseif cond="instrument == 'fiddle'" />
<prompt>Does playing classical music on a fiddle make it a
violin?</prompt>
<elseif cond="instrument == 'banjo'" />
<prompt>Wow, I hope you live alone.</prompt>
</if>
</filled>
</form>
</vxml>

13. Playing a Sound
 The Audio Element
 Must be contained with a block:
<block>
<audio src="ui/welcome.wav">
Welcome
</audio>
</block>

14. Voice XML Inputs
Voice XML accepts:
 Touch tone key
 Speech
There is a difference between voice
recognition and Voice XML.
 Personal voice recognition systems allow
for wide grammar, but restrict the number
of users.
 Voice XML restricts the grammar, but
allows for a wide number of users.

15. Goals of voicexml
 Minimizes client/server interactions by
specifying multiple interactions per
document.
 Separates user interaction code (in
VoiceXML) from service logic (e.g. scripts).
 Promotes service portability across
implementation platforms.
 Is easy to use for simple interactions, and
yet provides language features to support
complex dialogs.

16. Advantages of Voice XML
 Allows for the easy implementation of
voice interfaces
 VoiceXML supports playback of
prerecorded audio files
 Runs on existing web infrastructure

17. Conclusion
Voicexml has become a standard:
 All-in-one solutions available
 Reduces dialogue system development
time
 Additional functions can be easily
implemented
 Develop our own dialogue system with free
VoiceXML browser

19. ANY Queries
???