Voice Extensible Markup Language or VoiceXML/VXML is a standard developed by the World Wide Web Consortium (W3C) for creating interactive voice dialogues.
Essentially, VoiceXML is to voice applications what HTML is to the web – it lets users leverage the web infrastructure already available for HTML to develop and deploy voice-based apps.
First launched in 2000, this standard for telephony controls remains relevant two decades on.
Understanding the Origins of VoiceXML
In March of 2000, a group of 500+ companies called the VoiceXML Forum first published the document’s version 1.0.
Since then, it has handed over ownership of the standard to W3C and supports individuals/organizations developing apps using VoiceXML.
It powers almost all voice-based UIs, despite its legacy nature. That's because of its simple core value proposition – enabling a voice browser where audio and keypad inputs are necessary to generate audio output.
In the context of modern app development, VoiceXML predates current programming languages - such as Python, Node.JS, etc. - and aligns best with Java-based applications. The most recent release of VoiceXML was in 2007, when version 2.1 came into being.
But does this mean that the VoiceXML standard is no longer essential or is irrelevant to CX? The answer is a resounding NO. After all, it is still commonly used in IVR systems.
Why VoiceXML Continues to be Integral to Telephony and CX
The closest replacement to VoiceXML is a deep neural network (DNN)-based speech-to-text, which processes audio input and generates audio output with far greater prowess and sophistication.
However, mature DNN technologies remain rare, and most companies are happy with partially modernizing VoiceXML apps into a JSON/YAML-friendly architecture. These architectures support integrations with RESTful APIs using web call-backs.
Moreover, VoiceXML is doubly relevant due to the more recent launch of CCXML.
CCXML adds to VoiceXML’s capabilities by introducing more granular call controls such as multi-participant conferencing and outgoing calls.
If doubts remain over VoiceXML’s readiness to take on the challenges of modern telephony, consider the VoiceXML Forum’s 2021 announcement to provide VoiceXML pioneers with $25,000 in grants.
Among the grant recipients is a researcher who developed a VoiceXML virtual agent for Alzheimer’s and dementia patient caregivers.