Engineering Full Stack Apps with Java and JavaScript
What is voice xml?
VoiceXML is a declarative, XML-based language markup language for writing telephone-based speech applications. Users call applications by telephone. They listen to spoken instructions and questions; they provide input using the spoken word and the touchtone keypad.
What does a VoiceXML interpreter do?
A VoiceXML interpreter renders VoiceXML documents audibly. You can think of the VoiceXML interpreter as a telephone-based voice browser. A user connects with your application by dialing the appropriate phone number. The VoiceXML interpreter answers the call and starts executing your VoiceXML document.
In order to support a telephone interface, the VoiceXML interpreter runs within an execution environment that includes a telephony component, a text-to-speech (TTS) speech-synthesis component, and a speech-recognition component. The VoiceXML interpreter transparently interacts with these infrastructure components as needed. For example:
Text strings in output elements are rendered using TTS.
Connection issues (picking up the incoming call, detecting a hang-up, transferring a call) are handled by the telephony component.
Listening to spoken input from the user and identifying its meaning is handled by the speech-recognition component.
Although both HTML and VoiceXML use markup tags, the two languages use tags differently. Briefly explain?
Whereas the markup tags in HTML describe how to render the data, the markup tags in XML (and consequently in VoiceXML) describe the data itself. This allows an XML interpreter or browser to display the data in whatever way is appropriate.
VoiceXML conforms to XML standards; the formats for VoiceXML tags are more strictly defined than are the formats in HTML.
In VoiceXML forms, each logical piece of information to be collected from the user is identified with a ………. tag.
<field>
The ………. tag specifies a block of client-side JavaScript code.
<script>
The ………. tag declares a variable to be used within the form.
<var>
The ………. tag produces audio output for the user.
<prompt>
The ………. tag assigns a value to a variable.
<assign>
The ………. tag evaluates an expression and produces spoken output of the result.
<value>
Describe the header information that needs to be added to every vxml application?
Every VoiceXML document must start with header information that conforms to the XML standard:
<?xml version="1.0" ?>
<!DOCTYPE vxml
PUBLIC "-//W3C/DTD VoiceXML 2.0//EN"
<vxml version="2.0" xmlns="http://www.w3.org/2001/vxml">