Control over audio playback
Music and audio that plays as the site loads presents a serious challenge to screen reader users. The audio from a movie created with Adobe® Flash® software can interfere with the end user's ability to hear the contents of a movie using a screen reader. As a result, it is important to make sure that the user has control over when music is played.
The simplest strategy for handling audio playback is simply to allow the end user to control audio with a play and pause button. Allowing the end user to initiate audio provides the experience of the audio without creating an additional hurdle.
A more advanced strategy for controlling playback relies on the use of keyboard shortcuts for audio playback. Providing global keystrokes that allow the user to control the audio can greatly enhance the experience for end users. Here are several controls to consider.
- Play and Pause
- Mute
- Volume
Play and Pause is typically controlled using a single keystroke, such as the letter "p," as a toggle. The first time the button is pressed, the audio starts to play. The second time the button is pressed, the audio is paused. A mute button, such as the letter "m" or the number "0," silences but does not stop the audio. This provides the screen reader user with the opportunity to listen to the screen reader temporarily without stopping the audio. When utilizing shortcut keys, it is important to consider potential conflicts with assistive technology keystrokes, such as quick navigation keys used by the JAWS screen reader.
Finally, volume controls allow the user to quietly play the audio in the background while still listening to the screen reader. This is most appropriate in cases where the audio does not require the focused attention of the user, as in the case of a music stream. Using the ability of Flash to detect assistive technologies, a developer might choose to automatically reduce or mute the audio for a movie to simplify the experience, while granting the user the flexibility to adjust the audio level if desired.
