There are different languages and methods to communicate and understand others without hearing any sound or only aided by very little sound.
However, some of these options work better when some amount of sound is available at the same time like some form of hearing aid or amplification.
As we talk and pronounce letters and words we move our mouths to form those sounds. Lip Reading aka Speech Reading is a technique of following what a person is saying by observation. This is easiest done with some amount of sound and requires a lot of practice that can take years to develop.
With this technique, since people talk differently, some people do not speak clearly and if a person talks to fast makes it hard to use this method to understand all people. Also this method requires a lot of concentration and can be tiring to do for lengthy periods of time.
American Sign Language was the first language for the deaf in the United States. Certain English speaking words are not necessary in deaf communication, which resulted in a structure of words different to English. Once understood this can be an easier language to sign since it includes fewer words than actual Spoken English.
ASL is a complete language and can be difficult to learn for late deaf individuals and their families.
There are alternate forms if Sign Language similar to ASL yet completely different in other countries. Example; BSL (British Sign Language).
ESL (English Sign Language) aka SEE (Sign Exact English). This form of sign language was created by hearing individuals. It uses different sign words from ASL and uses Spoken and Written English Structure.
Pigeon is a combination of ASL and ESL. Typically ASL sign words with English Structure or some combination.
Late deaf individuals typically resort to a form of Pigeon Sign Language for communication.
The Rochester Method is fingerspelling only. This method requires learning only the characters of the alphabet. This takes much longer to do than spoken language.
As hearing starts to diminish it is a good idea to learn Fingerspelling if nothing else is learned.
Fingerspelling in England is known as Makaton sign.
Cued Speech is not a language but a Manually Coded Sign System that can work well along with Lip reading. One of the problems with Lip Reading alone is that many characters look the same when spoken.
Cued speech is a phonemic-based system that can help differentiate those common appearing characters.
There are different versions of Sign Language for different verbal languages in the world. Within the same country and different communities there are variations on different and unique sign words, where even letters for Fingerspelling might be different.