Audism, along the line of racism, sexism, and so on, is widely prevalent that most hearing people don't realize 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.
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 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, judging a deaf person's English when not knowing that she/he may be an immigrant, and so on.
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/