Common Desktop Environment: Style Guide and Certification Checklist

Hearing Disabilities

People with hearing disabilities either cannot detect sound or may have difficulty distinguishing audio output from typical background noise.

Never assume that users will hear an auditory notice. Remember that users sitting in airplanes, in noisy offices, or in other public places where sound must be turned off need the same types of visual notification as hearing impaired users. Additionally, some users are able to hear audible cues only at certain frequencies or volumes. Volume and frequency of audio feedback should be easily configurable by the user. Never hard code these parameters.

Sounds unaccompanied by visual notification, such as a beep indicating that a print job is complete, are of no value to users with hearing impairments or others who are not using sound. While such sounds can be valuable, never create a design that assumes sounds will be heard.

On the other hand, it would be intrusive for most users to see a warning window whenever a printout is ready. Visual notices can take the form of changing an icon, posting a message in an information area, or providing a message window as appropriate. Anyone using a system in a public area will benefit from the option of choosing to see rather than hear such notices.

The key point is to provide users with a choice. When appropriate, provide visual as well as audio notification. If visual notification does not make sense as the default behavior, then be sure to provide it as an option.

Guidelines

Recommended 

ii: 

Interactions do not depend upon the assumption that a user will hear an audible notification. 

Recommended 

ij: 

Where appropriate, users can choose to receive cues as audio or visual information. 

Recommended 

ik: 

The application does not overuse or rely exclusively on audible information. 

Recommended 

il: 

Users can choose to configure the frequency and volume of audible cues.