Microaggression is defined as "a statement, action, or incident regarded as an instance of indirect, subtle, or unintentional discrimination against members of a marginalized group such as a racial or ethnic minority." Source
Harvard University psychiatrist and professor Chester M. Pierce coined the term "microaggression" in the 1970s to describe the subtle behaviors.
"What makes microaggressions different from other rude or insensitive actions or comments?"
"They're something very specific: the kinds of remarks, questions, or actions that are painful because they have to do with a person's membership in a group that's discriminated against or subject to stereotypes. And a key part of what makes them so disconcerting is that they happen casually, frequently, and often without any harm intended, in everyday life." Source
Here are some examples of everyday real-life scenarios of microaggression experienced by Deaf people.
"Field trip to a local theater to see an ASL play: Students K12 were there from their various placements: One of their teachers asked me if I were a teaching assistant. No, I teach 4th graders. That just stuck in my mind. Ugh." -- Lala DeLumeau, April 2020.
"Oh, you're deaf? ... Oh poor, you're so beautiful." -- from a hotel maid to a Deaf teenager in the 1990s. "You don't look deaf." -- one of some common experiences. "You speak well." "Not hear anything at all? How do you read and write English so fluently?"
"Did you know that there is a wonderful technology called cochlear implants that might help you?" "Why don't you get a cochlear implant?"
Video: "I have long been known as an unappreciative troublemaker who is selfish for not letting sleeping dogs lie. And yet I endure." -- American Deaf lawyer and advocate Kelby Brick. Source
Another example is when professors or teachers turn off captioning or subtitle in class because it is distracting for other students, ignoring the deaf student's need.
A hearing person asks the interpreter a question such as "What is the sign for (word)?" instead of asking the Deaf/hard-of-hearing person.
A disability service coordinator assigns a different support/need that the student may not need or want.
Other forms of microaggression that Deaf students may experience are patronization and infantilization. Infantilization is defined as not allowing a person with a disability to perform actions they are perfectly capable of doing.
"Deaf people cannot function in the hearing world."
A hearing preschool teacher asked a Deaf mother of the 3-year-old coda who was in her class, "What is the sign for cauliflower?" The mother replied, "Fingerspelling." The teacher signed, "Oh, it's hard and it's a long word. I had to make up a sign for 'cauliflower'".
More reading: "What exactly is a microaggression?" By Jenée Desmond-Harris. Feb 16, 2015. https://www.vox.com/2015/2/16/8031073/what-are-microaggressions