XML News from Friday, October 24, 2008

The W3C Voice Browser Activity has published the finished recommendation of Pronunciation Lexicon Specification (PLS) Version 1.0. This is an XML syntax for specifying pronunciation lexicons for Automatic Speech Recognition and Speech Synthesis engines in voice browser applications:

The language allows one or more pronunciations for a word or phrase to be specified using a standard pronunciation alphabet or if necessary using vendor specific alphabets. Pronunciations are grouped together into a PLS document which may be referenced from other markup languages, such as the Speech Recognition Grammar Specification [SRGS] and the Speech Synthesis Markup Language [SSML].

In its most general sense, a lexicon is merely a list of words or phrases, possibly containing information associated with and related to the items in the list. This document uses the term "lexicon" in only one specific way, as "pronunciation lexicon". In this particular document, "lexicon" means a mapping between words (or short phrases), their written representations, and their pronunciations suitable for use by an ASR engine or a TTS engine. Pronunciation lexicons are not only useful for voice browsers; they have also proven effective mechanisms to support accessibility for persons with disabilities as well as greater usability for all users. They are used to good effect in screen readers and user agents supporting multimodal interfaces.