Children who are born deaf or lose their hearing ability in their infancy can learn to speak if they are fitted with suitable hearing aids and trained early enough. Children who become deaf after having already acquired oral language can be trained to retain their speaking ability.
‘Dumb’ is, increasingly, a term with demeaning connotations associated with the mental capacity of a person. It is insulting for a deaf person, who has difficulty in speaking clearly because he does not hear sounds clearly, to be called ‘Dumb’. Speech-impairment may be a disability in some situations but it does not make the person any less intelligent.
Children who do not acquire oral language can be trained to communicate using other modes of communication. Either way, with timely intervention, deaf children can perform at par with hearing children, and are not mentally inferior.
The universally acceptable terms are ‘deaf’ or ‘hearing-impaired’.