“How many times have you been asked this question: if you had to choose, which would you prefer to be: deaf or blind? The question illustrates the misconception that deafness is in some way the opposite of blindness — as though there’s some sort of binary representation of disability. When we look at accessible Website design for the deaf, it’s not surprising to see it addressed in a similar fashion to accessibility for the blind.
Video captioning by itself oversimplifies the matter and fails many Deaf people. To provide better user experiences for the Deaf, we need to stop thinking of deafness as simply the inverse of hearing — we need to understand deafness from both a cultural and linguistic perspective. Moreover, to enhance the online user experience for the deaf, we must understand how deafness influences web accessibility.”
The above is a snippet from an excellent article about website accessibility for the deaf and hard of hearing, it is written by Lisa Herrod, you can read it in full on the A List Apart site.