In accordance with AP style, use the lowercase form “deaf” for the physical condition of total or major hearing loss. You can use “hard of hearing” to describe people with a lesser degree of hearing loss.

Many deaf people use the uppercase form “Deaf” to signify their identification with a culture shared among deaf people who use sign language. If you’re writing a specific piece of copy about a person or group that uses the uppercase form, it’s acceptable for you to also use it in phrasings such as “Deaf community,” “Deaf culture,” and so on.

However, don’t use the uppercase form in reference to an individual person; instead, use lowercase “deaf” to describe an individual. For example: 

Smith, who has been deaf since childhood, said Deaf culture plays a defining role in her life.