Visual feedback and lip-positioning skills of children with and without impaired hearing.

Interplay between visual feedback and lip-positioning skill was studied in 10 5- to 14-year-old children with normal hearing and 10 with severe to profound hearing impairment. With visual feedback, the subjects in both groups had similar response times and accuracy in matching six visually specified lip separation "targets." Special skill in processing visual information by the hearing-impaired subjects was suggested by higher velocities of lip movement toward the targets and shorter latencies in reaching the goal positions. In the responses of the hearing children, lip-closing movements were executed more accurately than opening movements both with and without visual feedback. In general, the findings showed that, given visually displayed lip-position targets and feedback from positioning actions, children can achieve the targets with high accuracy regardless of hearing status or prior speaking experience.