The Deaf, Deafblind, Deafened and Hard of Hearing are each very distinct groups in their own way. Using the proper terminology shows respect for their uniqueness.

Terminology, Definitions & Explanations

Deaf (with capital D)
A sociological term referring to those individuals who are medically Deaf or Hard of Hearing who identify with and participate in the culture, society and use the primary language, which is Sign Language.

deaf
A medical/ audiological term referring to persons who have little or no functional hearing. May also be used as a collective noun ("the deaf") to refer to persons who are medically deaf but who do not necessarily identify with the Deaf Community.

Deafened (also known as late-deafened)
This is both a medical and a sociological term referring to individuals who have become deaf later in life and who may not be able to identify with either the Deaf or Hard of Hearing Communities.

Hard of Hearing
A person whose hearing loss ranges from mild to profound and whose usual means of communication is speech. It is both a medical and a sociological term. A person who is able to hear speech using assistive devises, can sometimes use the phone and listen to music. Some HOH people use ASL or other sign systems, but often have fluency in English as well. Often the person is raised in the hearing community and associates more with the hearing culture, although that is not always the case.

hearing impaired
This term is not acceptable when referring to persons with a hearing loss. It should never be used in referring to Deaf persons. "Hearing impaired" is a medical condition; it is not a collective noun for people who have varying degrees of hearing loss. It fails to recognize the differences between the Deaf, Deafblind, Deafened and Hard of Hearing Communities.
This label was created by hearing people to be politically correct, although Deaf people do not like this term because they do not feel that they are impaired in any way.

oral deaf
A deaf person whose preferred mode of communication is verbal and auditory and/or lip-reading/ speech-reading. An oral deaf person who can both Sign and speak can be considered "Deaf" if he/she is accepted as such by other Deaf persons and uses Sign within the Deaf community.

Deaf-plus
Although it has been used for many years to refer to people who have disabilities in addition to deafness, the preferred terms now are "Deaf with mental disabilities", "Deafblind", "Deaf with CP", etc.

Hearing (upper-case "H")
A general term when referring to the Hearing Community.

hearing (lower-case "h")
A general term when referring to hearing persons when in reference to their ability to hear.

deaf-mute
Unacceptable. A deaf person may choose not to use his/her voice; this does not make him/her a "mute".

deaf and dumb
Offensive.

Sign Language
Sign Language is the official language of the Deaf Community. When written it should always be capitalized, just as "English" and "French" are capitalized because all three are legitimate languages.

American Sign Language (ASL)
ASL is a visual signed language used by the Deaf in the United States and most provinces of Canada. ASL is not a universal language; it has existed for several centuries in North America, and started out as a mixture of French Sign Language, existing signs brought in by Deaf Martha's Vineyard residents, and home-made signs brought in by Deaf students at the American School for the Deaf (ASD) in Connecticut. It is a unique three-dimensional language with its own grammatical rules and syntax (sentence structure), and is every bit as precise, versatile, and subtle as English
However, it wasn't until 1960 when William Stokoe first identified ASL as a native and a natural language. ASL has its own grammatical structure and rules that govern the way words combine to form phrases and sentences. ASL is a distinct language, separate from English. The grammatical structure of ASL has more in common with Romance Languages (such as French, Spanish, or Italian) than it does with English, and there are some words or phrases in ASL that are not easily translated to English or any other language. Like all other languages, ASL has evolved to reflect the needs of its users.

Fingerspelling
The manual alphabet in sign language. Fingerspelling is used primarily for names, places, and objects without a sign.

International Sign (IS)
IS was created in order for Deaf people to communicate more effectively at international Deaf conferences. There is a dominant influence from ASL and European Sign Languages thus African and Asian signers find IS considerably more difficult to understand. IS does not have a fixed grammar, so some argue it's better defined as a vocabulary rather than a complete language. IS cannot be learned in the classroom, but by socialization with international Deaf individuals. This is the current Sign Language used at international Deaf conferences.

PSE (Pidgin Sign English)
Mixed ASL and English signs, signed following the English language (remember ASL is not English).

Signed English
A sign language based on English used by many late-deafened and oral deaf individuals. A person who knows Signed English will not understand ASL unless they are bilingual in both languages. Signed English is not a true language and is confusing and hard to understand for native ASL users.

Deaf Interpreters (DI)
A Deaf Interpreter is a deaf person who has been trained to provide interpreting services to Deaf consumers who may have linguistic impairments that prevent them from fully utilizing a traditional ASL interpreter. The DI works as a part of team with a hearing ASL interpreter. The ASL interpreter interprets in ASL to the Deaf Interpreter and they then interprets the ASL message into a visual communiqué that is customized to suit the specific needs of the Deaf consumer.
The DI may make use of mime, props, circumstantially-relevant language entities and other mechanisms to ensure that the message is effectively communicated to the Deaf consumer. This type of interpreting is sometimes called "relay interpreting." However, a "relay interpreter" is not necessarily the same thing as a using a DI which can make for the most efficient use of time and clarification of linguistic or cultural confusion that may occur with some Deaf consumers.

Tactile Interpreting
Some people are not only Deaf, but blind as well. When Deafblind consumers have little to no vision they need to receive linguistic information by feeling the interpreter's hands while the interpreter signs or fingerspells. This can also be called tactile interpreting.
With tactile interpreting, the interpreter typically sits or stands next to the Deafblind consumer while interpreting. The interpreter also adds visual descriptions along with the interpreted message. Depending on the consumer's preference, tactile interpreters may either be a CDI or a hearing ASL interpreter.

Low-Vision Interpreting
Unlike Deafblind individuals, some Deaf consumers have vision impairments that render them able to see signs only at close range. The low-vision consumer may request an interpreter that specializes in this type of interpreting. In order to ensure that the consumer sees the low-vision interpreter as clearly and easily as possible, lights may be placed in such way to illuminate the interpreter's face and hands.

Hands-On Signing
This is used by some Deafblind individuals. It is an adaptation of signing in which the receiver remains in physical contact with the signer, so she can feel the hand-shapes and movement of the signer's hands and feel the fingerspelling.

Speech-reading
The practice of getting meaning from a person's lip movements; also known as lip-reading. Used mostly by the late-deafened and hard-of-hearing individuals, who have a lifetime of contextual hearing understanding of the language being spoken.

Communication Access Realtime Translation (CART)
CART is a method of live captioning which is typically provided during meetings or conferences so that a Deaf, Deafened or Hard of Hearing person are able to read what is being said. The CART provider is usually a Captioner with courtroom typing experience who uses a court reporting machine to type in text, which is then fed into a computer and displayed on a screen for the audience's viewing.

TTY
The proper acronym for a specially designed telephone used by Deaf, Deafblind, Deafened and Hard of Hearing and hearing people to communicate with each other through the telephone system. The French term is ATS.

TT (Text Telephone)
Used in some European countries and by the Federal Communications Commission of the United States as a substitute term for "TTY". Not accepted in Canada because it is a hearing-invented term and because the Sign for it is impolite in ASL.

Relay Center
Message relayed between a Deaf person using a TTY and a hearing person on the phone through the operator.

Video Relay Services (VRS)
Video Relay Services provides a new communication tool that allows a person whose primary mode of communication is ASL the ability to communicate effectively and naturally with the hearing world. VRS uses the internet and a Videophone device as a link to a qualified, certified Sign Language Interpreter who interprets between the visual language of ASL and the auditory language of a hearing person. Canada is still in the process of setting up this service.

C.C.
Closed-captioned or closed-captioning; subtitle-like captioning on television.

Deaf Culture
All the individuals within the Deaf Community and their local cultures contribute to what is Deaf Culture. Deaf culture is a collection of bonds that hold Deaf people together. These bonds include: a common language (ASL) and values, among others interests.

Deaf Community
Deaf individuals with a history as a community that goes back for generations. They have a defined system of beliefs and patterns of behavior which have been passed down for generations and live within a society of people who hear.

C.O.D.A.
'Child of Deaf Adults', which means hearing children of Deaf parents. CODA’s grow up within the Deaf Community and many become Sign Language Interpreters or work in the Deaf Community as adults.

Deafie(s)
Slang referring to Deaf person(s).

Hearie(s)
Slang referring to hearing person(s).