Finding your way:

Accessible Web Page Design:
Making Audio Accessible.

There are really two issues here:

1. Making the audio clips you include on your site accessible to persons who are hard of hearing or deaf.

2. Using audio clips containing descriptive information as an accessible alternative for persons who are blind.

Text alternatives for users who are hard of hearing.

Hear a 26K byte message (in .WAV format) or,
read the text of the message.

Guideline: If the file contains a speech or spoken passage, provide a link to a textual version. While people who are deaf or hard of hearing will appreciate this accommodation, you will also add benefit for the large number of people that do not yet have a sound-card in their computer.

Also be sure to indicate its format (.WAV, .AU, etc.) and file size in kilobytes: no one wants to download a 100K byte file and THEN learn they can't play it on their system.

Reality Check: If you are publishing sound clips of instrumental music on your site, I don't think anyone expects you to publish the sheet music as an accommodation. However, if you are delivering music that includes vocal tracks, then it might be appreciated if you include the lyrics in a linked file. Of course, all of this assumes that you have worked out any copyright issues beforehand.

Using audio as an alternative to descriptive text.

Recent advancements in tools for delivering information and multimedia on the World-Wide Web have, for the most part, decreased the overall accessibility to information on the Web. One exception may be the new audio-on-demand applications that are becoming popular. These deliver a highly compressed stream of audio information to your PC in real time. It is possible to deliver very long audio clips via these systems -- far more efficiently, although at much reduced quality, than is possible by downloading .WAV or other digitized audio formats. For instance, the five word sentence that I speak in the above example requires you to download a twenty-six thousand byte file. Using traditionally digitized methods to deliver long speeches is impractical -- no one really wants to download a million byte file just to hear a few moments of speech or music. Audio-on-demand seems to have solved this problem, although the quality of sound may not suite all ears.

There is one major difference between traditional sound capture and audio-on-demand for developers wanting to include sound on their site: in the PC world anyone with a sound card and microphone can capture and replay .WAV files (or equivalent on other computer platforms) and include them on their web-pages. However, to deliver audio-on-demand you need special software on your web-server to deliver it, as well as still needing the local audio input and output capabilities. If you can deliver audio-on-demand from your site, be sure to inform visitors to your page how they can acquire the client-software necessary to receive your chosen audio-on-demand format.

As multimedia PCs become more common, and as audio-on-demand systems become better and more widely accepted, then real-time audio may become a viable alternative format for describing graphics or even delivering the entire content of your web site. But remember: do not use audio-on-demand at the expense of textual information... you will exclude people who are hard-of-hearing.

Finding your way.

General design tips.
Are columns accessible?