You know mostly of people does called Deaf people "Dumb and Mute" that they think it's ok to call them like that. But a Deaf person doesn't like that when hearing people call them by insulting. Understand this time was long time ago in old fashion time they don't know what to called to deaf people, they use "Dumb and Mute" that what their first words. Until few years later, hearing people changed from "Dumb and Mute" to Deaf or Hard of Hearing.
However, there are still going on by called "Dumb and Mute" also think that deaf people should be put as handicap or retarded. But deaf people felts that they have been insulted. Sometime hearing people has discrimation on deaf people about driving, jobs, and many more, deaf people are same as hearing people are humans.
Therefore, hearing people is very picking on deaf about not able to do anything that all.
Deaf people wanted to show them that they can do anything; just especially unable hear anything that's all.
I went through same experience with other deaf people who has problem with hearing people in all years. I was born hearing but became deaf by allergic reaction to D.P.T. shot. My parent is hearing. They have learned a lot about my being deaf and learn about deaf culture about sign language to communicate and learn how I can do anything with my abilities.
I remembered in years ago when I was young age; my mom and I went to food store to buy something. When my mom and I were standing the line to waiting for cashier. The lady stand behind me and starting shoted said "Will you move along? are you dumb and mute? Are you retarded?" As when my mom heard it from her.