Audism, along the line of racism, sexism, and so on, is widely prevalent that most hearing people aren't aware of it. First, let's define the term audism, coined by Tom Humphries in 1975. Audism is invariably defined as:
Audism n. 1. The notion that one is superior based on one's ability to hear or behave in the manner of one who hears. 2. A system of advantage based on hearing ability 3. A metaphysical orientation that links human identity with speech. -- (1) Tom Humphries, (2) Wellmann (1992), (3) Deaf Studies conference by Bahan and Bauman, 2000.
Image screenshot from Crack the Audism (2003), www.lapiak.com.
Let's explore scenarios related to audism that happened in real life.
"A Deaf administrator told me this: a [hearing] parent had come to his superior objecting to their child being placed in a classroom headed by a Deaf teacher. The superior listened for a half hour of parental concerns about speech modeling and so on, then incredulously exclaimed, 'You want to prevent your child from becoming a teacher of deaf children, too?'" -- Dianrez, 2011. 
The best educational experiences that many Deaf children have are the Deaf teachers and a few hearing teachers who are fluent in ASL and have excellent attitude toward Deaf children, such as the belief that Deaf children are as fully capable as hearing children.
A few more examples of other behaviors of audism in employment are: hiring a hearing person over a better qualified deaf person for a job position; dismissing a job application without giving a deaf person an interview when she/he may be the best worker...
Other examples of audism on language: judging a deaf person's English when not knowing that she/he may be an immigrant; judging Deaf people how well they can hear and speak when they can read and write English well at the graduate level...
Video above: The Holcomb family members share their experiences of audism in educational settings. Their stories are kind of universal among many Deaf people of the days.
Deaf people see themselves as a linguistic-cultural ethnic group and they are all human beings with intelligence and human feelings no different from hearing people.
 Dianrez. Accessed, June 20, 2011. http://handeyes.wordpress.com/2011/06/17/ an-answer-to-mishka-zena%E2%80%99s-noble-and-just-question/
Look at institutional audism on a larger scale.