Glossary » hearing impairment
difficulty hearing or deafness. For those who are hard of hearing, volume controls can help them use a computer, as well as output devices that enable them to plug in headphones and control the position and direction of speakers. For deafness or partial deafness, provide an option to turn off sound in the interface and use alternative ways of displaying information, such as closed captions, and providing visual alerts instead of or in addition to audio alerts.
Many of these solutions for users with hearing impairments are quite useful to unimpaired users who work in noisy environments or wish to work without having audio disturb others around them.