On PHPBuilder.com today Jason Gilmore has a new tutorial showing how to create voice recognition applications with PHP and the help of open source voice interpretation tools.
Voice recognition or speech recognition technology is not easy to develop. In-house development would be very costly, and buying proprietary libraries that convert voice to text would make the developed application very expensive for end users. On the other hand, when developing in PHP, you have many open-source solutions available. The same dilemma happens with voice recognition in PHP -- there is an open-source class that can be used in voice applications. That way your application would cost less, and you also can offer it for free.
His tool of choice is Voice PHP, an open source project that uses four classes with support for SSML, SRGS, CCXML and VoiceXML. In his sample application he shows how to use the libraries to generate an application that can listen to a user's voice and translate that into certain menu options.