Deafness

Deafness is when someone cannot hear or cannot hear well. There were many famous people who were deaf, such as Ludwig van Beethoven and Helen Keller. Deafness is also known as 'hearing loss'.

Definition

A person is considered to be deaf if they cannot hear the same range of sounds as a person with normal hearing ability. People that cannot hear any sounds are also deaf. People who are partially deaf may hear some sounds and may hear words.

Things that help deaf people

• Hearing aid, which helps a deaf person to hear sounds.
• Teletypewriter (TTY), that allows a deaf person to communicate with people.
• Sign language, which allows a deaf person to have a conversation with someone else.
• Hearing dog is a dog that has been trained to hear sounds and help a deaf person.

Causes

There are different causes of deafness:

• Age: People will lose their hearing as they get older.
• Exposure to noise: A noisy environment may affect the hearing of people and cause people to become deaf.
• Genetic conditions: There can be a family history of deafness. If the mother and/or father are deaf, their child will have a strong chance of being deaf.
• Diseases: Certain diseases may cause deafness.
• Drugs: Certain drugs may affect hearing.
• Chemicals: Certain chemicals can damage the ear.

Categories of deafness

These categories may overlap.

• Unilateral -- loss of hearing in one ear only
• Pre-lingual – deafness at birth or deafness that started before language is learned
• Peri-lingual – deafness that started while learning a first language
• Post-lingual – deafness that started after a language has been learned
• Partial – limited hearing loss
• Progressive – hearing loss that becomes worse as time passes
• Profound – complete or near-complete hearing loss
• Tone deaf – not able to hear differences in relative pitch (in music)
• Tinnitus – hearing damage that causes high pitched ringing. This makes it so that the person cannot hear other sounds