In medical terms the word “acquired” is often used when referring to a condition or a disease that affects a person after birth, therefore opposite to “congenital” when an individual is born with a condition.
When the term “acquired deafblindness” is used it generally refers to adults who have become deafblind at a later stage in their life. Acquired deafblindness may also be described as “acquired dual sensory impairment (ADSI) or “acquired dual sensory loss” (ADSL).
In the field of deafblindness, reference is made more specifically to children or adults who experience a combination of significant vision and hearing loss after they have developed a means of communication whether that is speech or using sign language. As discussed in “Congenital Deafblindness” although not born with a condition, a child may become deafblind at a young age before they have been able to master a language system for communication purposes and would therefore be considered congenitally deafblind.
Reference to the terms “acquired deafblindness” or “acquired dual sensory loss” means that a person was not born with this condition; instead they became so at a later stage in their life.
People who are not totally deaf and blind are sometimes confused if the term “deafblind” is used, and may prefer “Acquired Dual Sensory Loss” or “Acquired Dual Sensory Impairment” to describe the deterioration of their two senses of vision and hearing.
As described in the section “About Deafblindness”, as a result of many different causes, there are three types of acquired deafblindness:
- A person who is born deaf or hard of hearing and later their vision starts to deteriorate
- A person who is born blind or vision impaired and later their hearing starts to deteriorate
- A person who is born with vision and hearing and later both senses start to deteriorate (not necessarily at the same time)
In rehabilitating people with acquired deafblindness to maintain independence, their skills in communication and other aspects of daily living prior to becoming deafblind will determine how they need to adapt those skills.
For a person who is born Deaf or hard of hearing and later their vision starts to deteriorate, language acquisition will depend on their level of hearing:
- When a person is born Deaf they may learn to use visual forms of communication through the use of lip reading and/or manual signs such as Australian Sign Language (Auslan), a language in its own right being the first language used by people in the Deaf Community. For people who have an intellectual disability they may use Key Word Sign (formerly known as Makaton).
- When born hard of hearing (or hearing impaired) a person may, or may not, wear a hearing aid or a cochlear implant depending on the level and type of hearing loss. They may be missing a percentage of conversations and therefore they are unable to rely on speech alone, lip reading may help to fill in the gaps.
- A person with a hereditary condition such as Usher Syndrome, where they are born Deaf or hard of hearing may start to experience gradual sight loss in their teens or early 20’s through Retinitis Pigmentosa (RP).
A person who is born blind or vision impaired and later their hearing starts to deteriorate:
- Being born blind or vision impaired, a person may have developed skills to use their hearing to compensate, relying on their listening skills in conversations, using audio feedback on television or radio, listening to talking books. Over the last 20 years the advances in technology have provided options with speech reading software on computers and other equipment.
- Whilst challenging, a person who is blind or vision impaired may have been taught orientation and mobility skills using a cane or a guide dog, and making best use of their hearing to identify auditory cues when out and about.
- For people who have residual vision they may have learned skills to make best use of their vision to be independent in everyday life.
A person who is born with vision and hearing and later both senses start to deteriorate (not necessarily at the same time):
- Having lived with vision and hearing intact it is likely that for most people they will have learned to use speech as their primary form of communication.
- Whether through accident, injury, disease or the ageing process a person may become deafblind. Under these circumstances the majority of people are likely to have some residual vision and/or hearing.
- The degree of functional vision and/or hearing that a person has will vary, as will the degree and rate of deterioration of the sense(s).