Anyone who speaks English as a native language knows that certain words can be pronounced differently and based on the pronunciation of the word, the meaning can change. In order to develop a website that can be heard by persons who have a vision disability, the ability to distinguish the differences between these pronunciations is important. As a result, the World Wide Web Consortium recommended the development and use of the PLS which is an acronym for the Pronunciation Lexicon Specification. This specification is used for speech recognition as well as speech synthesis, but emphasis is placed on the synthesis portion of it.
While developed traditionally for the use in the English language, there was also the realisation that in other worldwide languages this pronunciation can be a burden as well. In Korea for example, the entire language is composed of syllables. When these syllables are combined in a particular fashion they then create a word which is distinguishable. Some of these syllables while written the same, are pronounced differently and can become an entirely different word altogether. As a result, the PLS was quickly recognised by the international community as well for the development of websites for the visually impaired internet surfer.
Using a standardised pronunciation alphabet, the PLS allows the developer to choose one or even many different pronunciations of a particular word depending on which meaning they wish to get across to the site’s visitors. Furthermore, for the use by the international community, vendor specific alphabets can also be created for various languages. Using the Speech Recognition Grammar Specification, the PLS document can be referenced in order to ensure that the understanding of the written words are clear. Using the Speech Synthesis Markup Language, this PLS file can also be accessed to make the synthesised words understandable.
The concept behind the PLS and the reason why W3C supports it is for the development and creation of more accessible websites which can be browsed by anyone, even those who are blind. With millions of websites and billions of pages already out on the internet, a visually impaired visitor will have a difficult time distinguishing what is on the page and this is because the vast majority of these websites are not accessible for them. More developers need to start focusing on the development of websites which can be visited by anyone, not just specific people of certain race, national origin, familial status, gender or handicap. An equal opportunity world free of discrimination and racism needs a World Wide Web which is also free of this hate and in many cases, sheer laziness.
Original Authors: Nick
Edit Update Authors: M.A.Harris
Updated On: 04/03/2009