Please be advised that the term, “hearing impaired” is unacceptable. Here is the explanation:
The term "Hearing Impaired" is a technically accurate term much preferred by hearing people, largely because they view it as politically correct. In the mainstream society, to boldly state one's disability (e.g., deaf, blind, etc.) is somewhat rude and impolite. To their way of thinking, it is far better to soften the harsh reality by using the word "impaired" along with "visual", "hearing", and so on. "hearing-impaired" is a well-meaning word that is much-resented by deaf and hard of hearing people.
While it's true that their hearing is not perfect, that doesn't make them impaired as people. Most would prefer to be called Deaf, Hard of Hearing or deaf when the need arises to refer to their hearing status, but not as a primary way to identify them as people (where their hearing status is not significant).
Hope that you and your people respect by refusing to use the outdated and offensive term.