[whatwg] Text-To-Speech (TTS) Web API for JavaScript

Olli Pettay Olli.Pettay at helsinki.fi
Thu Dec 10 17:42:46 PST 2009

On 12/10/09 4:54 PM, Weston Ruter wrote:
> I've been working on a web app which reads text in a web page,
> highlighting each word as it is read. For this to be possible, a
> Text-To-Speech API is needed which is able to:
> (1) generate the speech audio from some text, and
> (2) include the time indicies for when each of the words in the text is
> spoken.
> Microsoft has its Sapi.SpVoice API via ActiveXObject which does (1) but
> not (2) apparently. There are web services (usable in conjunction with
> HTML5 Audio) which also do (1) such as the iSpeech API
> <http://www.ispeech.org/api> and Google Translate's TTS
> <http://translate.google.com/translate_tts?q=Hello%2C+World&tl=en
> <http://translate.google.com/translate_tts?q=Hello%2C+World&tl=en>>, but
> none that I have found which do (2). In any case, web services
> aren't preferable since they require that the audio be transferred over
> the network which could take a significant amount of time.
> Is anyone aware of any work done to develop a standard TTS API for the
> Web? Operating systems already have this functionality built-in, and
> it's a shame that web apps can't make use of it. If Google Gears were
> alive, it would've been a good place to prototype this, but alas…

You probably want to ask W3C multimodal working group.
There are specifications like XHTML+Voice and SALT
(neither really W3C specifications) and (old) proposals like


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