Britannica.com has a great article and definition of audism (which I have summarized and clarified here—why re-invent the wheel?):

Audism (by Dr. H. Dirkson Bauman): The belief that the ability to hear makes one superior to those with hearing loss. Those who support this perspective are known as audists, and they may be hearing or deaf. The term audism was coined in 1975 in an unpublished article written by American communication and language researcher Dr. Tom L. Humphries as a way to describe discrimination against persons who are deaf.

So just like other "-isms", audism is based on hearing ability and status. An interesting point is that the audist can be hearing or deaf (or have any varying hearing ability in-between!). Dr. Bauman goes on to state that: Audism manifests in the form of people who continually judge deaf people’s intelligence and success on the basis of their ability in the language of the hearing culture. It can also appear when deaf people themselves “actively participate in the oppression of other deaf people by demanding of them the same set of standards, behavior, and values that they demand of hearing people.”

There's both an out-group pressure/judgment on deaf people's abilities, and an in-group pressure/judgment and expectation on each other. This can be seen by the expectation that "Deaf-of-Deaf parents" (even going back multiple generations) hold more esteemed positions in the Deaf Community, but only for those who use ASL as their primary language and support/conform to their local Deaf Community and members.

In 1992, American psychologist and speech researcher Harlan L. Lane wrote Mask of Benevolence: Disabling the Deaf Community and described audism as a way for the hearing to dominate the deaf community with environments tailored for deaf persons, limited in their visual stimulation, continuing to give advantage to hearing persons. He introduced the idea of institutional audism—hearing ability was favoured over inability to hear.

Institutional oppression is inherently difficult to detect, for it often masks itself as practices that follow "common sense": hearing-as-norm.

Audism has roots that extend to fundamental questions of human identity. The idea of metaphysical audism, which is based on the concept that speech is fundamental to human identity, emerged in the late 20th and early 21st centuries, with the work of American English professor Brenda Brueggemann and American professor of deaf studies H-Dirksen L. Bauman. Brueggemann identified the problematic syllogism on which metaphysical audism rested: “Language is human; speech is language; therefore deaf people are inhuman and deafness is a problem.”

However, the realization of the grammatical nature of sign languages and research in neurolinguistics suggest that every human is able to communicate via spoken, signed, or written language. Thus, speech is not the only language of humankind.

Awareness of audism has increased in the deaf and hearing communities, and it is now considered to be a matter of human rights and dignity for a linguistic minority to have access to a fully human language that best fits their visual learning needs.

Thus, the discourse around audism allows its users to perceive the overarching drive to normalize deaf persons into hearing persons as a severe instance of discrimination and oppression at the hands of a ruling majority.

(Almost entirety of article taken from Britannica.com)

Examples of Audism*

• “People who can talk/hear are more educated than those who do not talk or hear.”

• Talking in front of a Deaf person when you know ASL.

• Assuming a Deaf person needs help.

• Asking a Deaf person to read your lips.

• Refusing to repeat something that was said.

• Encouraging oralism instead of looking at what is best for the child

• Diagnosing Deaf children with disabilities when they have not had access to language

Intentional vs. Unintentional*

• Many instances of audism are unintentional or passive

• Some instances are intentional but “excused”

• We are human and make mistakes

• Even Deaf people can perpetuate audism

  • Hearing aids, cochlear implants, hard of hearing, Deaf born to hearing families

Some Helpful Tips*

• Support Deaf businesses, events, and individuals

• Ask the Deaf person what they prefer

• Recognize hearing privilege

• Use positive labels such as "Deaf" or "Hard of Hearing", "hearing level", "Deaf gain" (instead of focusing on the "hearing loss")

• Avoid assumptions of a Deaf person’s intelligence based on interpreters’ ability

*Heather Arazi, Notes/Slides on "Audism", 2019.

Sorenson--Deaf History Month: What is Audism?

HSDC Equity Team: addressing Audism