COMB in ADJYou use -impaired in adjectives where you are describing someone with a particular disability. For example, someone who is hearing-impaired has a disability affecting their hearing, and someone who is visually-impaired has a disability affecting their sight.
More than 1 in 20 of the population is hearing-impaired to some extent...
There are 1.7 million blind and visually impaired people in Britain.COMB in N-PLURAL: the NThe hearing-impaired or the visually-impaired are people with disabilities affecting their hearing or sight.
...giving a voice to the speech-impaired.
English dictionary. 2008.