Ways to Communicate with a Deaf-Blind Person
There are many ways of communicating with a deaf-blind person. If you happen to come across a deaf-blind person, let them tell you how to communicate with them. This list is just to help familiarize you with some of the ways beforehand. Before reading the list, please note that most deaf-blind people have some usable vision or hearing. Because a deaf-blind person can't compensate for the loss of one sense with the other, even a partial loss of both senses can be considered deaf-blind. So a "deaf-blind" person might be totally blind and hard of hearing, totally deaf and partially sighted, or may be close to totally blind and close to totally deaf but have some usable vision and hearing. Generally people that are only a bit vision- and hearing-impaired are referred to as vision-impaired/hard-of-hearing. But for someone who is totally one and partially the other, it's not uncommon to be considered deaf-blind.
Because of the wider definition of deaf-blindness, some deaf-blind people can use auditory or visual ways to communicate, but just need these ways to be modified for their poor vision or hearing. A good number of deaf-blind people can use some vision or hearing in some situations but are functionally totally deaf-blind in other situations. Some deaf-blind people are truly completely deaf and completely blind and therefore can only use tactile methods of communication in all situations.
1) Print on palm
This method involves printing letters on the palm of the person's hand. The way it works is that you use your finger as a writing utensil and write on the palm of their hand. When doing this, draw big, clear block letters. Make each letter fill up the whole palm. It takes a lot of concentration and effort on the deaf-blind person's (for most people), so make the letters as clear as possible when doing this. Small letters or cursive letters are nearly impossible to distinguish by touch. Though this may seem obvious, remember to write on their palm and not your own.
2) The Deaf-Blind Manual alphabet
The Deaf-Blind Manual alphabet is a modified version of the British Manual Alphabet, or the hand shapes used to finger spell in British Sign Language. This method can be found all over the Internet and learned quickly. It's just 26 hand shapes to indicate each letter of the alphabet. The original British alphabet uses two hands to form each letter, but the Deaf-Blind alphabet is modified so that you move your hand on the deaf-blind person's passive hand. Depending on where and how you make contact with their hand, it forms a letter. When finger spelling, make sure to do it clearly because many of the letters feel the same with sloppy signing. Better clarity than speed.
3) Large Print Notes
For someone who is totally deaf and legally blind, they might be able to see enough to see big letters on paper. In this case you might exchange notes on paper just as you would with a deaf-sighted person, but you would need to write or type in large bold letters. Let the person tell you what is easiest for them to read (all caps, bold, which font works best on a computer, etc.)
4) Speech with amplification
For someone who is totally blind and hard of hearing, they might still be able to understand speech through a hearing aid or FM system, which are both ways of amplifying speech. An FM system only amplifies, which makes speech louder but not clearer. Therefore several people talking in a room at once or a lot of background noise will still make it hard or impossible for the blind/hard-of-hearing to understand. Hearing aids are custom-made to the person's hearing loss so they tend to improve speech comprehension much more effectively. However, it can still be hard to make sense of sound in a noisy area.
5) Tactile finger spelling
Some deaf-blind people like to use what is called the Rochester Method, tactually. This is where you finger spell the American Sign Language (or whatever other sign language is used locally) into their hand. This obviously requires knowing the sign language alphabet. Don't assume all deaf-blind people know sign language. (Some went deaf later in life and haven't learned sign language.) But if both you and they know finger spelling, this method can be used. Keep in mind to let the deaf-blind person choose where to place their hand to interpret your finger spelling. Resist the temptation to correct their hand placement or hold their hand. They know where to hold their hand to understand, not you.
6) Close range sign language
Some deaf-blind people use full blown sign language at a close range, most commonly deaf-blind people who grew up or have spent a lot of time in a Deaf community using sign language for communication, and have lost some vision but still have enough to see signing up close. This obviously requires you knowing sign language. So if you do, you can sign to them, closer than usual.
7) Tracking sign language
This is used most often by deaf-blind people who grew up or have spent a long time using sign language and now have tunnel vision and can only see in the central part of their field. The way this works is that you sign normally, but let them hold your wrists to ensure your hands stay within their visual field. Sometimes this is done by you standing farther away than usual and signing within a small space so as to stay within their tunnel vision field.
8) Tactile sign language
Deafblind people that know sign language but have no useful vision for taking in signs visually receive it tactually. This means that as you sign to them, they place their hands lightly over yours and feel your signs. This requires you to sign in a smaller space than usual, so as to relieve the stress on their arms and shoulders. Let the deaf-blind person choose how to place their hands. They know what placement helps them understand best. Resist the temptation to sign big, exaggerated signs, because this ends up in extremely sore arms and shoulders for both of you the next day. Generally this requires an advanced knowledge of sign language so you can know how to make signs more neutral in space without sacrificing their meaning. The signs used are the same, except for some occasional modifications to make up for lack in facial expression and to disambiguate some signs that are hard to distinguish by touch. Usually this is done by finger spelling the sign right before or after signing it, or by coupling it with another sign. (An example is disambiguating "chicken" and "twenty" by signing "number twenty" and "chicken c-h-i-c-k-e-n.")
9) A deaf-blind communication device or braille display
Some deaf-blind people have a specific device for facilitating communication, where you can type back and forth, and where you receive visual output and they receive braille output. This can also be done with a TeleBraille (braille TTY, kind of like a phone for the deaf-blind) or a computer attached to a braille display. Again, you simply type to them, let them read the braille, and they can either type back to you or speak back to you, depending on if they can speak or not.
10) Braille card
This method is generally used for deaf-blind people that don't know print well or that have a hard time understanding print-on-palm. This involves having a card with the alphabet on it, both in print and braille. The way it works is you place their finger on the braille characters and spell out your message. Remember to point their finger onto the braille character and not the print character above/below it. Though this may seem obvious, remember to point their finger to the card and not your own.
11) Tadoma Method
This method is rarely used nowadays but you might still come across it. It's essentially tactile lipreading. The deaf-blind person places their hand or hands on your nose, mouth, jaw, and neck to feel the vibrations of your speech and understand your speech through these vibrations. The accuracy of comprehension from this method varies.
12) Co-active signing
This involves using sign language, but instead of signing in your own space and on your own body, you sign on the deaf-blind person's body. This method is generally reserved for deaf-blind people with a cognitive disability, but might also be useful for deaf-blind people with tactile issues who have a hard time interpreting direct tactile information and therefore need added kinesthetic information. A way to do this with letters is to move the deaf-blind person's arm, wrist, or finger in the shape of the letters.
13) Finger braille
This method is generally used with deaf-blind people who are familiar with a braille but don't know (enough) sign language. A braille typewriter, or Perkins brailler, has 6 keys representing each of the 6 dots of braille, and a space bar. To type braille, the person uses "chording" (where they hit one or more of the keys at once) corresponding to each of the 6 possible positions in the cell that is dotted for a particular cell. Finger braille works by typing on a virtual Perkins brailler, formed by three points on each wrist or palm. Each hand rests on the palm or the wrist of the person in the same configuration as the Perkins keys, and then you "type" to them.
Please remember that not all deaf-blind people know sign language or braille, or they might not feel fluent enough to use it as a method of communication. Braille doesn't come with blindness, nor sign language with deafness. They come with practice and usage. Let them offer which method to use so you don't have to play a guessing game. Another thing to keep in mind is that some deaf-blind people can speak and some can't. Some can speak but prefer not to because they have trouble making themselves understood. Speech skills don't necessarily relate to hearing loss, so just because someone speaks well doesn't mean they hear pretty well.
Generally speaking, people that went deaf before or around the time they started learning to speak have much more obstacles to overcome in terms of learning to speak. If they've gone deaf before/around learning to speak, they've had to rely on visual or tactile methods to learn speech, which is a lot harder to do than learning it by ear. Despite the added difficulty, some pre-lingually deaf people have achieved great speech skills and you might not even be able to tell they're deaf/hard-of-hearing based on their speech.
On the other hand, late-deafened people have learned to speak before they lost some or all of their hearing, so in general, these people have normal or close to normal speech. Generally late-deafened people have a harder time with volume control but otherwise maintain clear speech. For people that have become progressively deaf over a long period of time, they might have been able to keep their speech up, or they might have started to forget what words sound and feel like and might start slurring or mispronouncing words.
The important thing to remember is that each person has a different ability in terms of speech. If the deaf-blind person uses speech, they can reply to you that way (unless you require a different method yourself), and if not, they will use other methods such as communicating back to you the same way you communicate to them (typing, finger spelling, signing, etc.)
Another thing to keep in mind is that a partial vision or hearing loss can mean useful hearing/vision in some situations and functional total deafness/blindness in other situations. Just because someone can read large print in a dim room doesn't mean they can in the bright sunlight, or just because someone can understand speech in a quiet room doesn't mean they can understand speech in a noisy room.
Other factors such as fatigue, hormonal changes, or the very nature of their cause of deafness/blindness may cause their level of hearing/vision loss to vary. Please make sure to understand that someone's functional hearing or vision isn't always the same, and that when they say they cannot hear you or see you now, even though they could last night/yesterday/last week, doesn't mean that they're lying or being lazy. It just means that for whatever reason, their functional hearing or vision is worse now because of the lighting/sound conditions or other factors mentioned before. Sometimes when fatigue sets in from trying to use residual hearing or vision itself makes the person unable to continue using it.
The variation in functional vision/hearing also means that many deaf-blind people use more than one form of communication depending on the situation. Someone who can hear speech in total silence may need tactile signing in a noisy place, and someone who can see signing in bright light may be totally blind in the dark and need to receive it tactually, etc. Adjust your communication method with them based on their needs. If you're not sure, let them tell you what they need for communication.