ˈhearing-imˌpaired adjective
a) not able to hear well Synonym : hard of hearing ⇒ deaf
b) the hearing-impaired people who are not able to hear well

[TahlilGaran] Dictionary of Contemporary English ▲

deaf adjective physically unable to hear anything, or unable to hear well:
Deaf people use sign language to communicate.
be hard of hearing to have difficulty hearing things, for example because you are old:
You’ll have to speak up – she’s a bit hard of hearing.
subtitles for the hard of hearing
hearing-impaired formal adjective having a permanent physical condition which makes it difficult for you to hear things:
Not all hearing-impaired people are completely deaf.

[TahlilGaran] English Thesaurus ▲