voice browsers

Introduction

This page describes and demonstrates voice browsing: that is, using a Web browser to speak the text of a page to you. There are two major cases where this would be useful: firstly, for vision-impaired people; secondly, where a handheld device (e.g. mobile phone) is being used which has a screen of very limited size. The latter possibility is exciting because it would offer an alternative to the physical limitations of very small screens when rendering Web content.

Vision-impaired users are already catered for by screen reader software such as JAWS. Screen readers take the screen output from a normal browser and then read the text on it. By contrast, a voice browser is a regular browser with additional voice capability. It is potentially much more powerful than a screen reader because the spoken text can be styled (with CSS) according to the design and content of the page. For example, elements of the page that are relevant only to the screen can be suppressed (e.g. menus). Different sections of text can be spoken in different voices, according to context.

At present, Opera is the only browser to have voice capability.

Demonstration

For a demonstration of voice browsing, you will need to download and install Opera 8.00 thru 8.54 and run it using Windows XP. From the Tools menu select Preferences and then Voice. Check the box Enable voice-controlled browsing. Press the Details... button and check the box Enable high quality text-to-speech. Select the text to be read and press V, or right-click and select Speak.

There are four situations in which Opera can operate as a voice browser:-

1. Opera can speak part or all of the text (as selected by the user) on any Web page. The page may be coded in HTML or XHTML. To speak the text, Opera uses its voice libraries. It doesn't depend on XHTML+Voice or CSS3 Speech support.

   You can try this scenario on any Web page, on any site!

2. The user can define a User Stylesheet in Opera containing voice rules. If the user then invokes the stylesheet, Opera can speak the text selected by the user on any Web page and it will be styled according to the CSS rules. The page may be coded in HTML or XHTML. To speak the text, Opera uses its voice libraries and its support for User Stylesheets and for the CSS3 Speech Module.

   You can try this scenario on any Web page, on any site, provided you know how to write a User Stylesheet and define it to Opera.

3. If a Web page (coded in HTML or XHTML) invokes a CSS stylesheet containing speech rules, then Opera can speak the text selected by the user and it will be styled according to the CSS rules. To speak the text, Opera uses its voice libraries and its support for User Stylesheets and for the CSS3 Speech Module.

   The present page is an example of this scenario. The main text is read in a male voice. Headings, panels and paragraphs are announced (cued) in a female voice (e.g. "New paragraph"). The text in the panels is read in a female voice.

   This sentence is styled with several CSS properties, including voice-volume, voice-balance, voice-rate, voice-family, voice-pitch, speech-speak and cue-after. Opera currently supports only voice-family, speech-speak and cue-after.

4. A Web page may be authored using XHTML+Voice and styled with speech rules. Opera can speak the text selected by the user and it will be styled according to the CSS rules. The use of XHTML+Voice enables the author to provide additional functionality, e.g. a button on the page which, if pressed, will cause the page text to be spoken. To speak the text, Opera uses its voice libraries and its support for XHTML+Voice and for the CSS3 Speech Module.

Opera also supports the separate but related facility of browser control by speech.