Review: GetVocal SDK

by Hitesh Seth

This week in our Product Review section, we take a look at GetVocal SDK from GetVocal, a division of Digital Voice Technologies.


GetVocal SDK is an integrated VoiceXML editor/simulator that enables the creation and testing of VoiceXML based applications. Built on top of Microsoft Speech Recognition technologies (Microsoft TTS and ASR engines), the SDK supports the latest VoiceXML 2.0 specifications (including the XML based Grammar formats). An evaluation copy of the SDK is available from the GetVocal website.


The SDK supports a variety of operating systems, including Windows 98, ME, NT, 2000 & Windows XP. The installation program, which is based on the Windows Installer, is pretty straight forward. Since the SDK utilizes Microsoft TTS & ASR engines, Microsoft Speech SDK 5.1 is a key requirement for the installation and must be installed prior to its installation.

First Looks

(click on the image to see a large view)

Creation of new VoiceXML content is done through a VoiceXML Application Wizard which sets up the basic speech recognition parameters, such as support for DTMF/Voice input modes, support for barge-in, wait time for user response, confidence level of the ASR, sound sensitivity, recognition accuracy, timeout intervals, terminating character for DTMF entry, etc. In the background this process creates a set of property elements in the VoiceXML content and is used in the actual execution in the SDK/gateway.

View Voice Application Wizard

After the basic VoiceXML file has been generated using the code generator (which is based on the context sensitive menu), the user can build on the VoiceXML content using various VoiceXML elements.

Once the VoiceXML application (including the grammars) have been developed, the SDK can then be used to test the application. The SDK provides features such as a virtual phone pad, debug mode with steps and breakpoints, variable watches and a runtime tag highlighter to aid in the testing/debugging of the VoiceXML application. On the other hand, if you have developed a server side application using technologies such as Java Server Pages (JSP), ASP/ASP.NET or Perl/PHP, the SDK provides you with the ability to test a remote HTTP based VoiceXML Application as well.

Standalone VoiceXML Editor

As part of the installation program two shortcuts are created - one which links to the main SDK (which we saw earlier) and the second which is just the editor. The standalone VoiceXML Editor (shown below), provides a simplified tool for just editing VoiceXML files. It is the same editor used by the SDK and has features such as color syntax highlighter and tag shortcut keys.

Single Port Gateway

The most distinct feature of the GetVocal SDK is that the SDK doubles as a single port VoiceXML Gateway. What that means is that if you have installed the SDK on a computer which has a Voice Modem with TAPI support, then apart from the regular simulation of the VoiceXML content using the desktop environment, you can actually "call" the SDK. The quality of the voice may not be the best (it depends on how good your modem is) but this feature makes the tool an excellent candidate for creating on the spot demonstrations and live testing.

Support for ActiveX/Java Components

For an application developed using Microsoft ActiveX/COM technology, GetVocal SDK can go a little further in development. Based on the VoiceXML <object> tag, the SDK provides support for instantiating and calling methods/properties on COM compliant objects. Java classes are also supported by the same mechanism, however for calling Java classes an additional step is required. Using the JavaReg tool in the Microsoft SDK for Java 4.0, the user is required to expose the Java class as a COM component.

Scripts based Automated Testing

Another useful tool provided by the SDK is the support for automated test scripts-based regression testing. For instance, an example would be if we had developed a simple Voice Portal which provides integrated weather reports and latest news. We could develop a simple test script which includes the spoken phrases and DTMF keystrokes (as shown below) and once the SDK is executed, it would automatically take input from the test script and run accordingly.


In nutshell, the VoiceXML SDK provides a basic development environment for VoiceXML based applications. Similar to the other VoiceXML tools available, the SDK does provide integrated editor/code generator; the highlight of the SDK is really its ability to utilize TAPI based interfaces and regular Voice capable modems and function as a Single Port VoiceXML gateway. Integrated project management, a better palette, support for dynamic (server side) application generation, standalone grammar testing would be among my picks for enhancement requests to future versions of the SDK.


About Hitesh Seth

Hitesh Seth is Chief Technology Evangelist for Silverline Technologies, a global eBusiness and mobile solutions consulting and integration services firm. He is a columnist on VoiceXML technology in XML Journal and regularly writes for other technology publications including Java Developer's Journal and Web Services Journal on technology topics such as J2EE, Microsoft .NET, XML, Wireless Computing, Speech Applications, Web Services & Integration. Hitesh received his Bachelors Degree from the Indian Institute of Technology Kanpur (IITK), India. Feel free to email any comments or suggestions about the articles featured in this column at hitesh.seth@silverline.com.

This article was originally published on Tuesday Nov 19th 2002
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