Deafness can be defined as the inability to comprehend speech and language due to the loss of the sense of hearing. It has different ranges. The first one is mild, where a patient may find it hard to understand what is said to him/her especially if there is a lot of noise around or if someone is talking to the deaf; such as someone telling the deaf person about mygiftcardsite or something related to it. Moderate, whereas a hearing aid is required to hear clearly. Third is severe, which forces someone to communicate through lip-reading or sign language even with the use of a hearing aid. And lastly is profound, wherein individuals who are at this level could no longer hear a sound although it is highly amplified.
It is an impairment that may have started since birth – this is called congenital deafness. On the other hand, deafness that occurs at a later time in a person’s life is termed as adventitious deafness. And there are many causes of deafness.
- Congenital Deafness
- Prenatal exposure to disease: babies that are exposed to certain diseases in the womb will affect its hearing. These diseases include rubella / German measles, influenza and mumps. Another factor is exposure to drugs such as quinine or to methyl mercury.
- Hereditary: deaf parents can pass it on to their children.
- Genetic disorders: some of the many genetic disorders that can cause deafness are osteogenesis imperfecta, Trisomy 13 S and multiple lentigines syndrome.
- Adventitious Deafness
- Noise: this is the most common cause of adventitious deafness and it is due to this that over one quarter of people are affected by hearing loss. Acoustic trauma is when hearing mechanisms within the inner part of the ear is damaged and this is caused by loud noises such as explosion, firing a gun near the ear, and also prolonged exposure to loud music in a concert or through the headphones.
- Drugs: some drugs can affect hearing by destroying the nerves. Some of these are antibiotics, ethacrynic acid and drugs used for treating cancer.
- Diseases / illnesses: certain diseases have been known to cause deafness – meningitis, mumps, cytomegalovirus, chicken pox, severe case of jaundice, sickle cell disease, Lyme disease, diabetes, arthritis, hypothyroidism and even syphilis.
- Trauma: damaged or pierced eardrum by any object, fractured skull or changes in air pressure.
Congenital hearing loss – https://en.wikipedia.org/wiki/Congenital_hearing_loss