Multimedia content with Rich Internet Applications using Dynamic HTML (DHTML) and Adobe Flash is now becoming popular in various websites. However, visually impaired users cannot deal with such content due to audio interference with the speech from screen readers and intricate structures strongly optimized for sighted users.

We have been developing an Accessibility Internet Browserfor Multimedia (aiBrowser) to address these problems. Thebrowser has two novel features: non-visual multimedia audiocontrols and alternative user interfaces using externalmetadata. First, by using the aiBrowser, users can directlycontrol the audio from the embedded media with fixed shortcutkeys. Therefore, this allows blind users to increase ordecrease the media volume, and pause or stop the mediato handle conflicts between the audio of the media and thespeech from the screen reader. Second, the aiBrowser canprovide an alternative simplified user interface suitable forscreen readers by using external metadata, which can evenbe applied to dynamic content such as DHTML and Flash.

In this paper, we discuss accessibility problems with multimedia content due to streaming media and the dynamic changes in such content, and explain how the aiBrowser addresses these problems by describing non-visual multimedia audio controls and external metadata-based alternative user interfaces. The evaluation of the aiBrowser was conducted by comparing it to JAWS, one of the most popular screen readers, on three well known multimedia-content-intensive websites.

The evaluation showed that the aiBrowser made the contentthat was inaccessible with JAWS relatively accessibleby using the multimedia audio controls and alternative interfaceswith metadata which included alternative text, headinginformation, and so on. It also drastically reduced thekeystrokes for navigation with aiBrowser, which implies toimprove the non-visual usability.