Sound Is Not Always Helpful For People Who Are Blind
Probably you have encountered situations where you open a site, or activate a link and you hear something through the speaker. This sound can be just background noise, or information you were looking for. It is a commonly known fact that people who are blind make use information which is in the form of sound. But is it always helpful?
Consider the following: people who are blind mostly use a screen reader to communicate with their computer. A screen reader reads aloud everything you type or information which appears on the screen. Now, if sound comes through the speaker, it makes it more difficult or impossible to listen to the screen reader. However, sound is still useful, so the question is, when to present sound, or how to present it so that people can stop it or pause it at any time.
As a rule, you should always provide instructions on disabling or pausing the sound even before it starts. Usually the best way to do it is to provide a keyboard shortcut and let users know beforehand which will allow them to do it. This is how people who are blind can use media players. Before they start playing the sound, they know what to press right away to disable the sound. What is even better, in some player, you can adjust the volume of the sound independently from the volume of the speaker. So, if you turn the sound volume down, you can still hear the screen reader. However, many players the volume control directly effects the speaker volume.
The other question is, what kind of sounds should be played. Personally, I categorize sounds into three areas:
Noise is what is good for nothing, it is there, not even sure why, probably to annoy people. It can be something like background beat, wave sounds, or elevator music.
Entertainment is what we consciously elect to listen to, such as music, ebooks, etc.
Information is something that helps people understand the content, for example a lecture, reading the site aloud, a description of a video, etc.
Entertainment and information definitely has validity, and use it to enhance the content. But always remember, let people know what's coming, and give them instructions on stopping or pausing it. This way you can enhance the experience of browsing the web for people, who are blind.