I know that the deaf communicate with sign language. But then, how does the deaf-blind communicate?

First, ASL (american sign language) and all other forms of sign language are accessible to Deafblind folk. We can either stand in close range of a person, stand in close range AND use a hand or two to keep their motions within our field-of-vision, or place one or both of our hands over their hands and follow the signs via tactile means.

We also use hearing aids, printed letters on palm, fingerspelling only, large-print note writing, computer or TTY communication systems, brailled communication cards or boards, visual or tactile speech reading, and so much more.

Most blind people are not completely blind, but rather have a visual impairment that makes it difficult to do things using sight that a normally sighted person would do using sight. Likewise, some d/Deaf people have enough hearing to communicate using spoken language in some circumstances.

People who have multiple disabilities often employ multiple strategies to deal with situations, depending upon circumstances.

For example, a person who has some usable sight may use a visual-only sign language, or they may use handwriting or typing. A deafblind person who has a developmental disability may use a picture board to communicate.

A person who has some hearing may use spoken language and a hearing aid.

Tactile written alphabets such as Moon type (more common in the U.K.) or braille may be used, especially if a person has a refreshable computer braille display.

A person may place their hands over the hands and arms of a person who is signing. There are also hands-on signed alphabets and some people have worked out ways of tapping out braille symbols on a person's hand. Since braille uses hundreds of abbreviations and contractions, this can be faster than using a regular signed alphabet.

Someone mentioned people who are legally blind and/or legally deaf. That complicates it, and can make it easier, either by the person being able to hear, or see. better. They use tactile signs.

Something I find more interesting is not how they communicate, but how they can be mobile. Could you imagine having to walk down a street being both blind and deaf? Well there are guide dogs that are specifically trained to work with blind/deaf persons, and I find that to be amazing and very helpful. That to me seems more interesting...

Have you heard the story of Helen Keller?

She was deaf, blind, and mute.

She was taught sign language and basic manners through, well quite honestly a miracle.

She wrote books and gave speeches through sign.

As for how they communicate with each other, I'm not sure.

Contact the Helen Keller institute in NYC. There is a man who works there who is deaf/blind - and was interviewed by Barbara Walters decades ago. He is an amazing man! Wish I could remember his name; but I remember he used to hold his fingers against someone's mouth as they spoke so he could comprehend what they were saying - and he had taught himself to speak.

Brilliant! Compassionate! Incredible man!

Read Nah's answer, but realize that people who are deaf/blind can be legally blind and see some and be totally deaf. Or hear some but be totally blind. Or see and hear some.

This is 2008 and where have you been?

Same way, only the hands have to be held the signing hands.

The following links may help.

URL: http://www.actionfund.org/ohsay/saysee18.htm

URL: http://www.deafblind.com/tipsdbp.html

URL: http://www.deafblind.com/info-db.html

I Hope this Helps!

Go rent "The Miracle Worker".