Most web sites rely on text to convey their messages. On sites that contain digitized content, there is generally a mix of still images and text. Yet we learn not only by reading words and seeing pictures, but also through hearing the spoken word, music and sounds. A site that can combine text to read, images to view, audio to hear, and video to watch allows the users to taken in information in different ways. That site provides a more meaningful experience.
Creating and building such a site takes much planning and forethought. More thought must be given to the equipment that users will have access to, and if that equipment will be sufficient. If the user will need additional software, then thought must be given to how that software will be obtain. Hopefully it will be painless and easy for the users to install.
One digitization project that does a nice job of including audio is the Martin Luther King Jr. Papers Project at Stanford University. When you go to the web site, you hear audio of Dr. King immediately. The initial audio requires QuickTime and, if it is not on the user's computer, the site asks the user if he would like to download it. Several audio clips are available on the site of his speeches, as well as in Adobe PDF format. So, for example, you can read and listen to his final speech (I've Been To The Mountaintop). (These speeches are available in both QuickTime and Real Audio formats.)
The site's interactive chronology includes text, images, audio and video. The chronology also has links to items that are for sale, like a book King published in 1967. Here the site assumes that you have to correct software installed to play the audio and video. If you do not, it doesn't even tell you what software is needed. So even a well designed site such as this has its flaws.
But even with its flaws, it is a site that should inspire a digitization project to include various types of media, giving users a fuller experience.