The term DEAF is used to describe people who have a hearing impairment. UNHEARING is a synonym for deaf, meaning unable to hear. EARLESS is another word for deaf, referring to the lack of ears. OBLIVIOUS is an adjective that can be used to describe someone who is unaware or not paying attention, which can be a common occurrence for those with hearing impairments. SIGN is a form of communication used by those who are deaf, such as SIGN language. TONE is a sound frequency that is used to communicate with those who are deaf, such as in the use of assistive listening devices.