What is deafness?

There are many definitions to the word "deaf." According to Stephen P. Quigley and Peter V. Paul in their book Language and Deafness (1984), "a child is considered deaf if hearing impairment is so great, even with good amplification, that vision becomes the child's main link to the world and main channel of communication." This is a general and relatively vague definition.

Other definitions are based on the degree of hearing loss in terms of decibels (dB) ranging from mild to profound hearing loss. A loss of 35 to 70 dB is generally considered hard of hearing, while a loss of 90 dB or greater is considered profoundly deaf. Each state classifies what is deaf and hard of hearing in different ranges. Check with your state or local County Office of Education for more information.

What are the types of deafness?

There are two general types of deafness:

A conductive hearing loss can be described as a temporary hearing loss due to an ear infection, wax buildup, ruptured ear drum, colds, atresia and otosclerosis. Note that otosclerosis can become a permanent hearing loss if not treated. The area of concern with conductive hearing loss is the middle and outer ear.

A sensorineural hearing loss is a permanent hearing loss in about 99.9% of cases. The causes of a sensorineural hearing loss are numerous: nerve damage due to illness, menengitis, maternal rubella, RH blood incompatibility, scarlet fever, absence of semicoclear fluid, cytomeglovirus, cronic exposure to loud noises (industrial work), premature birth, head trauma, drug exposure,heredity/genetics and unknown causes. The areas of concern with sensorineural hearing loss are in the inner ear.

References

Moores, David. Educating the Deaf: Psychology, Principles, and Practices. Houghton Mifflin Company. Boston.1996.

Quigley, Stephen P. and Paul, Peter V.. Language and Deafness. College-Hill Press, San Diego, CA. 1984.