What Is a Voice Portal?
A voice portal is really nothing more than a call center with connections to Web services, some voice recognition services for navigation, a speech synthesis engine for converting text output to the caller, and, usually, some kind of programming or scripting capability. A voice portal application provides a service that can be accessed from the convenience of a telephone or a cell phone. VoiceXML (VXML) is emerging as a popular standard for scripting dialogs. This article focuses primarily on the use of Java to develop voice applications, but we’ll discuss the advantages of VXML in Part 2 of this series. A voice portal application must talk to its user. All user input and output is through narrow-bandwidth audio channels. A voice application must operate efficiently and reliably with nothing more than audio input and output in a narrow range between 30 and 4,000Hz. A voice portal application developer is essentially a signal processing engineer. Developers must write applications that
