The term deafness refers to inability to receive spoken messages with ease. Deafness is loss of sense of hearing. This can be complete or partial loss.
- 5% of deafness is due to genetic reasons
- 30% results from damages and diseases during pregnancy and birth
- 40% of deafness result from infections and diseases e.g meningitis, malaria etc
- 10% of deafness is a result of accident and physical mistreatment
- 15% of deafness has no known cause
To date there exist no successful medical or technological treatment for profound deafness. A few people with partially impaired hearing can gain some degree of hearing with the help of learning aids or rely on Sign Language or lip reading techniques.
The term hearing impairment is a general term that refers to people who have problems with hearing. They can be divided into two different groups i.e. hard of hearing and deaf. Deaf people can be divided into sub groups according to the time of the hearing loss. There are groups which solely rely on Sign Language.
- Congenitally Deaf
Refer to a person who was born deaf and never heard of any spoken Language. This group of Deaf people is fully dependant on Sign Language and cannot learn the spoken language of the surrounding
- Prelingually Deaf
Refer to a person who was born hearing but lost it before mastering the spoken language of the family at approximately the age of 5 and below. This group of people cannot ably speak the spoken language of the hearing community.
- Post Lingually Deaf
A person who was born hearing and lost it only after learning the spoken language of the environment. At approximately after 10 years onwards. If given proper support can be able to speak the language of the hearing community
It is important to make a distinction between these three groups in order to understand why some deaf people can speak while some find it difficult to learn how to speak as he /she has never heard any spoken language but has no idea of how speech sounds.
This is more or less true for prelingually Deaf child without only vague memories of sound. A post lingually deaf child or adult may be able to speak although the voice of a deaf person may sound different. But if it is important to understand that even if it is difficult for a deaf child to learn how to speak, it is not at all impossible to teach the child how to read and write through sign language.
Hard of Hearing
Refer to people who can hear the spoken language to some extent but it may take them time to receive the message such people can benefit from use of hearing aids.