Depending on the remaining functions of the limbs, head, or articulation organs, various types of aids are available to motor impaired persons for controlling technical devices. For those with their speech organs and speaking ability unimpaired, an innovative approach has recently become available through voice input which uses speech recognition to automatically identify spoken input. This mode permits the largest possible information input per time unit, may however involve faulty recognition. Practical applications of speech recognition systems for motor impaired persons lie in the private and occupational settings, with purposes ranging from telecommunication, environmental control, to locomotion or computer control. Examples are the speech-controlled use of a television set or a wheelchair. Apart from controlling technical devices, voice input may, in other disabling conditions, also be employed to aid human communication. An overview of commercial speech recognition devices is given.